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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

FORM 10-Q

(Mark One)


☒	QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the quarterly period ended March 31, 2026


☐	TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the transition period from ______________________ to ______________________

Commission File Number: 001-43254

Seaport Therapeutics, Inc.

(Exact Name of Registrant as Specified in its Charter)


Delaware	99-2235719
(State or other jurisdiction of incorporation or organization)	(I.R.S. Employer Identification No.)
101 Seaport Blvd., Floor 12 Boston, Massachusetts	02210
(Address of principal executive offices)	(Zip Code)

Registrant’s telephone number, including area code: (617) 807-4062

Securities registered pursuant to Section 12(b) of the Act:

      Title of each class

      Trading
Symbol(s)

      Name of each exchange on which registered

      Voting Common Stock, $0.0001 par value per share

      SPTX

      The Nasdaq Global Select Market

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ☐ No ☒

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes ☒ No ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.


Large accelerated filer	☐	Accelerated filer	☐
Non-accelerated filer	☒	Smaller reporting company	☒
		Emerging growth company	☒

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes ☐ No ☒

As of June 5, 2026, the registrant had 53,530,550 shares of voting common stock, $0.0001 par value per share, outstanding.

Table of Contents


		Page

PART I.	FINANCIAL INFORMATION	4

Item 1.	Financial Statements (Unaudited)	4
	Condensed Consolidated Balance Sheets as of March 31, 2026 and December 31, 2025	4
	Condensed Consolidated Statements of Operations and Comprehensive Loss for the Three Months Ended March 31, 2026 and 2025	5
	Condensed Consolidated Statements of Convertible Preferred Stock and Stockholders’ Deficit for the Three Months Ended March 31, 2026 and 2025	6
	Condensed Consolidated Statements of Cash Flows for the Three Months Ended March 31, 2026 and 2025	7
	Notes to Unaudited Condensed Consolidated Financial Statements	8
Item 2.	Management’s Discussion and Analysis of Financial Condition and Results of Operations	23
Item 3.	Quantitative and Qualitative Disclosures About Market Risk	33
Item 4.	Controls and Procedures	33

PART II.	OTHER INFORMATION	34

Item 1.	Legal Proceedings	34
Item 1A.	Risk Factors	35
Item 2.	Unregistered Sales of Equity Securities and Use of Proceeds	99
Item 3.	Defaults Upon Senior Securities	99
Item 4.	Mine Safety Disclosures	100
Item 5.	Other Information	100
Item 6.	Exhibits	101
Signatures		102

SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This Quarterly Report on Form 10-Q contains forward-looking statements about us and our industry that involve substantial risks and uncertainties. All statements other than statements of historical facts contained in this Quarterly Report on Form 10-Q, including statements regarding our future results of operations and financial position, business strategy, product candidates, planned preclinical studies and clinical trials, results of preclinical studies, clinical trials, research and development costs, regulatory approvals, commercial strategy, timing and likelihood of success, as well as plans and objectives of management for future operations, are forward-looking statements. These statements involve known and unknown risks, uncertainties, and other important factors that are in some cases beyond our control and may cause our actual results, performance, or achievements to be materially different from any future results, performance, or achievements expressed or implied by the forward-looking statements.

In some cases, you can identify forward-looking statements by terms such as “may,” “will,” “should,” “would,” “expect,” “plan,” “anticipate,” “could,” “intend,” “target,” “project,” “believe,” “estimate,” “predict,” “potential,” or “continue” or the negative of these terms or other similar expressions. Forward-looking statements contained in this Quarterly Report on Form 10-Q include, but are not limited to, statements about:

• the initiation, timing, progress and results of our current and future clinical trials, preclinical studies, and research and development programs;

• the timing of announcement of results from clinical trials;

• our ability to successfully complete our clinical trials;

• our ability to advance other product candidates that we may identify and successfully complete any clinical studies, including the manufacture of any such product candidates;

• our ability to quickly leverage programs within our initial target indications and to progress additional programs to further develop our pipeline;

• the prevalence of certain disorders we intend to treat and the size of the market opportunity for our product candidates;

• estimates of the number of patients with certain disorders we intend to treat and the number of patients that we will enroll in our clinical trials;

• the likelihood of our clinical trials demonstrating safety and efficacy of our product candidates;

• the timing of our investigational new drug applications, or INDs, submissions;

• the implementation of our strategic plans for our business, platform, and our programs;

• the scope of protection we are able to establish and maintain for intellectual property rights;

• developments related to our competitors and our industry;

• the success of competing therapies that are or may become available;

• our ability to leverage the clinical, regulatory, and manufacturing advancements to accelerate our clinical trials and approval of product candidates;

• our ability to meet future regulatory standards with respect to our product candidates, if approved;

• our ability to maintain our existing license agreements and identify and enter into future license agreements and collaborations;

• our reliance on third parties to conduct clinical trials of our product candidates;

• our reliance on third parties for the manufacture of our product candidates;

• developments related to our platform;

• regulatory developments in the United States and foreign countries;

• our commercialization, marketing, and manufacturing capabilities;

• our expectations regarding the period during which we will qualify as an emerging growth company under the JOBS Act or a smaller reporting company;

• our ability to attract and retain key scientific and management personnel; and

• our anticipated cash runway, our financial performance, estimates of our expenses, capital requirements, and needs for additional financing.

We have based these forward-looking statements largely on our current expectations and projections about our business, the industry in which we operate and financial trends that we believe may affect our business, financial condition, results of operations and prospects, and these forward-looking statements are not guarantees of future performance or development. These forward-looking statements speak only as of the date of this Quarterly Report on Form 10-Q and are subject to a number of risks, uncertainties and assumptions described in "Risk Factor Summary," “Risk Factors” and elsewhere in this Quarterly Report on Form 10-Q. Because forward-looking statements are inherently subject to risks and uncertainties, some of which cannot be predicted or quantified, you should not rely on these forward looking statements as predictions of future events. The events and circumstances reflected in our forward-looking statements may not be achieved or occur and actual results could differ materially from those projected in the forward-looking statements. Except as required by applicable law, we do not plan to publicly update or revise any forward-looking statements contained herein until after we distribute this Quarterly Report on Form 10-Q, whether as a result of any new information, future events, or otherwise. Our forward-looking statements do not reflect the potential impact of any future acquisitions, mergers, dispositions, collaborations, joint ventures, or investments that we may make or enter into. In addition, statements that “we believe” and similar statements reflect our beliefs and opinions on the relevant subject. These statements are based upon information available to us as of the date of this Quarterly Report on Form 10-Q, and while we believe such information forms a reasonable basis for such statements, such information may be limited or incomplete, and our statements should not be read to indicate that we have conducted an exhaustive inquiry into, or review of, all potentially available relevant information. These statements are inherently uncertain, and you are cautioned not to unduly rely upon these statements.

You should read this Quarterly Report on Form 10-Q and the documents that we have filed as exhibits to this Quarterly Report on Form 10-Q completely and with the understanding that our actual future results may be materially different from what we expect. The forward-looking statements contained in this Quarterly Report on Form10-Q are made as of the date of this Quarterly Report on Form 10-Q, and we do not assume any obligation to update any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by applicable law.

This Quarterly Report on Form 10-Q may include industry and market data, which we may obtain from our own internal estimates and research, as well as from industry and general publications and research, surveys, and studies conducted by third parties. Industry publications, studies, and surveys generally state that they have been obtained from sources believed to be reliable, although they do not guarantee the accuracy or completeness of such information. While we believe that such studies and publications are reliable, we have not independently verified market and industry data from third‑party sources.

Website and Social Media Disclosure

From time to time, we may use our website (www.seaporttx.com), investor and media relations website (investors.seaporttx.com), LinkedIn page (http://www.linkedin.com/company/seaport-therapeutics), Bluesky (https://bsky.app/profile/seaporttx.bsky.social), and X feed (https://x.com/SeaportTx) as channels for the distribution of information. The information we post through these channels may be deemed material. Accordingly, investors should monitor these channels, in addition to following our press releases and subscribing to our email alerts, Securities and Exchange Commission filings and public conference calls and webcasts. The contents of our website and social media channels are not, however, a part of this report.

Risk Factor Summary

Investment in our securities involves risk. You should carefully consider the following summary of what we believe to be the principal risks facing our business, in addition to the risks described more fully in Part II. Item 1A, “Risk Factors” in this Quarterly Report on Form 10-Q and other information included in this report. The risks and uncertainties described below are not the only risks and uncertainties we face. Additional risks and uncertainties not presently known to us or that we presently deem less significant may also impair our business operations.

If any of the following risks occurs, our business, financial condition and results of operations and future growth prospects could be materially and adversely affected, and the actual outcomes of matters as to which forward-looking statements are made in this report could be materially different from those anticipated in such forward-looking statements.

•

We are a clinical-stage therapeutics company, have no history of generating commercial revenue, have a history of operating losses and may never achieve or maintain profitability.

•

Company management has obtained and continues to pursue additional financing to support future operations, however such funding may not be available on acceptable terms or at all.

•

We are substantially dependent on the success of our drug product candidates, and significant additional research and development and clinical testing will be required before we can potentially seek regulatory approval for or commercialize any of our drug product candidates.

•

Our proprietary Glyph platform is based on a novel approach that may not result in approvable or marketable products, which exposes us to unforeseen risks and makes it difficult for us to predict the time and cost of product development and potential for regulatory approval.

•

Success in pre-clinical studies or early clinical trials may not be indicative of results obtained in later trials.

•

We have concentrated our research and development efforts on the treatment of disorders of the brain and central nervous system, a field that faces certain challenges in drug development.

•

We may conduct clinical trials for our product candidates outside of the United States and the FDA may not accept data from such trials, in which case our development plans may be delayed, which could materially harm our business.

•

We may not be successful in our efforts to identify additional drug product candidates. We must prioritize the development of certain drug product candidates, and these decisions may prove to be wrong and may adversely affect our business.

•

We expect to expand our organization, and as a result, we may encounter difficulties in managing our growth, and our future growth depends on attracting, hiring and retaining our key personnel and recruiting additional qualified personnel.

•

We rely on third parties to assist in conducting our clinical trials and preclinical studies, manufacture our product candidates and seek to establish collaborations on product development and commercialization plans.

•

Our commercial success depends on our ability to obtain, maintain, enforce, and otherwise protect our intellectual property and proprietary technology.

•

We are an “emerging growth company” and a “smaller reporting company” and have elected to take advantage of the reduced reporting requirements applicable to emerging growth companies and smaller reporting companies, and we will continue to incur significant costs associated with operating as a public company.

PART I—FINANCIAL INFORMATION

Item 1. Financial Statements.

Seaport Therapeutics, Inc.

Condensed Consolidated Balance Sheets

(In thousands, except share and per share amounts) (Unaudited)


	March 31,			December 31,
	2026			2025
Assets
Current assets:
Cash and cash equivalents	$	52,909		$	46,042
Short-term investments		129,696			169,941
Prepaid expenses and other current assets		5,736			7,247
Total current assets		188,341			223,230
Property and equipment, net		386			412
Right-of-use assets - operating leases		5,066			4,813
Long-term investments		30,037			17,670
Other non-current assets		3,843			2,884
Total assets	$	227,673		$	249,009
Liabilities, convertible preferred stock and stockholders' deficit
Current liabilities:
Accounts payable	$	4,787		$	2,007
Related party payable		11			7
Accrued expenses and other current liabilities		7,826			9,131
Operating lease liability		1,599			1,637
Total current liabilities		14,223			12,782
Operating lease liability, net of current portion		3,743			3,444
Total liabilities		17,966			16,226
Commitments and contingencies (Note 14)
Series A-1 convertible preferred stock, par value $0.0001; 40,000,000 shares authorized, issued, and outstanding; liquidation preference of $4,000 as of March 31, 2026 and December 31, 2025		—			—
Series A-2 convertible preferred stock, par value $0.0001; 26,342,102 shares authorized, issued, and outstanding; liquidation preference of $100,100 as of March 31, 2026 and December 31, 2025		99,757			99,757
Series B convertible preferred stock, par value $0.0001; 47,578,938 shares authorized; 47,578,934 shares issued and outstanding; liquidation preference of $226,000 as of March 31, 2026 and December 31, 2025		225,571			225,571
Stockholders' deficit
Common stock, par value $0.0001; 159,070,000 shares authorized; 2,595,342 and 2,594,960 shares issued and outstanding as of March 31, 2026 and December 31, 2025 respectively		1			1
Cumulative translation adjustment		—			—
Additional paid-in capital		23,831			21,262
Accumulated other comprehensive income		64			301
Accumulated deficit		(139,517	)		(114,109	)
Total stockholders' deficit		(115,621	)		(92,545	)
Total liabilities, convertible preferred stock and stockholders' deficit	$	227,673		$	249,009

The accompanying notes are an integral part of these condensed consolidated financial statements.

Seaport Therapeutics, Inc.

Condensed Consolidated Statements of Operations and Comprehensive Loss

(In thousands, except share and per share amounts) (Unaudited)


	Three Months Ended March 31,
	2026			2025
Operating expenses:
Research and development (including stock-based compensation expense of $0.9 million and $0.5 million for three months ended March 31, 2026 and 2025, respectively)	$	21,431		$	10,534
General and administrative (including stock-based compensation expense of $1.7 million and $1.1 million for the three months ended March 31, 2026 and 2025, respectively)		6,112			5,651
Total operating expenses		27,543			16,185
Loss from operations		(27,543	)		(16,185	)
Other income (expense), net
Interest income, net		2,133			3,100
Research and development tax credit		567			—
Other expense, net		(46	)		(9	)
Total other income, net		2,654			3,091
Loss before income taxes		(24,889	)		(13,094	)
Income tax provision		519			31
Net loss	$	(25,408	)	$	(13,125	)
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustment		15			—
Unrealized (loss) gain on available-for-sale securities		(252	)		192
Comprehensive loss	$	(25,645	)	$	(12,933	)

Net loss per share, basic and diluted	$	(10.34	)	$	(5.65	)
Weighted-average common shares outstanding, basic and diluted		2,456,766			2,323,724

The accompanying notes are an integral part of these condensed consolidated financial statements.

Seaport Therapeutics, Inc.

Condensed Consolidated Statements of Convertible Preferred Stock and Stockholders’ Deficit

(In thousands, except share amounts) (Unaudited)


	Series A-1 Convertible Preferred Stock				Series A-2 Convertible Preferred Stock				Series B Convertible Preferred Stock				Common Stock				Additional					Accumulated Other			Total
	Shares		Amount		Shares		Amount		Shares		Amount		Shares		Amount		Paid-In Capital		Accumulated Deficit			Comprehensive Income			Stockholders’ Deficit
Balance as of December 31, 2025		40,000,000	$	—		26,342,102	$	99,757		47,578,934	$	225,571		2,595,342	$	1	$	21,262	$	(114,109	)	$	301		$	(92,545	)
Stock-based compensation expense		—		—		—		—		—		—		—		—		2,569		—			—			2,569
Unrealized loss on investments		—		—		—		—		—		—		—		—		—		—			(252	)		(252	)
Cumulative translation adjustment		—		—		—		—		—		—		—		—		—		—			15			15
Net loss		—		—		—		—		—		—		—		—		—		(25,408	)		—			(25,408	)
Balance as of March 31, 2026		40,000,000	$	—		26,342,102	$	99,757		47,578,934	$	225,571		2,595,342	$	1	$	23,831	$	(139,517	)	$	64		$	(115,621	)

Balance as of December 31, 2024		40,000,000	$	—		26,342,102	$	99,757		47,578,934	$	225,571		2,594,960	$	1	$	14,378	$	(39,228	)	$	—		$	(24,849	)
Stock-based compensation expense		—		—		—		—		—		—		—		—		1,619		—			—			1,619
Unrealized gain on investments		—		—		—		—		—		—		—		—		—		—			192			192
Net loss		—		—		—		—		—		—		—		—		—		(13,125	)		—			(13,125	)
Balance as of March 31, 2025		40,000,000	$	—		26,342,102	$	99,757		47,578,934	$	225,571		2,594,960	$	1	$	15,997	$	(52,353	)	$	192		$	(36,163	)

The accompanying notes are an integral part of these condensed consolidated financial statements.

Seaport Therapeutics, Inc.

Condensed Consolidated Statements of Cash Flows

(In thousands) (Unaudited)


	Three Months Ended March 31,
	2026			2025
Operating activities
Net loss	$	(25,408	)	$	(13,125	)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense		2,569			1,619
Depreciation expense		26			36
Amortization of operating lease right-of-use assets		331			279
Net amortization of premiums and discounts on investments		(223	)		(835	)
Changes in operating assets and liabilities:
Prepaid expenses and other current assets		1,571			(2,655	)
Other non-current assets		-			(1,191	)
Accounts payable		2,780			(2,003	)
Related party payable		4			(229	)
Accrued expenses and other current liabilities		(1,499	)		(1,871	)
Operating lease liability		(323	)		(230	)
Net cash used in operating activities		(20,172	)		(20,205	)
Investing activities
Purchases of investments		(47,150	)		(225,497	)
Proceeds from maturities of investments		75,000			—
Purchases of property and equipment		—			(54	)
Net cash provided (used in) investing activities		27,850			(225,551	)
Financing activities
Payment of deferred offering costs		(783	)		—
Net cash used in financing activities		(783	)		—
Effect of exchange rates on cash and cash equivalents		(28	)		—
Net increase (decrease) in cash and cash equivalents		6,867			(245,756	)
Cash, cash equivalents, and restricted cash, beginning of period		46,496			309,553
Cash, cash equivalents, and restricted cash, end of period	$	53,363		$	63,797

Supplemental disclosure of non-cash operating, financing, and investing information:
Operating lease right-of-use assets obtained in exchange for lease liabilities	$	584		$	1,114
Deferred offering costs included in accounts payable and accrued expenses	$	541		$	—

The accompanying notes are an integral part of these condensed consolidated financial statements.

Seaport Therapeutics, Inc.

Notes to Condensed Consolidated Financial Statements

1. NATURE OF BUSINESS AND BASIS OF PRESENTATION

Background

Seaport Therapeutics, Inc., and its consolidated subsidiaries, Seaport or the Company, is a clinical-stage therapeutics company focused on inventing and developing medicines for patients with depression, anxiety, and other debilitating neuropsychiatric disorders using the Company's proprietary Glyph Platform.

The Company's lead product candidate, GlyphAllo ("Glyph Allopregnanolone"), is a Glyphed oral prodrug of allopregnanolone, an endogenous molecule that has been clinically validated in two third-party trials in the United States for the treatment of postpartum depression, or PPD, a form of major depressive disorder, or MDD, as a rapidly acting antidepressant with anxiolytic and sleep-promoting effects.

The Company's second product candidate, GlyphAgo ("Glyph Agomelatine"), is a Glyphed oral prodrug of agomelatine, a clinically validated anxiolytic and antidepressant that is approved for the treatment of generalized anxiety disorder, or GAD, in Australia and MDD in Australia and the European Union, or EU.

The Company is also advancing Glyph2BLSD (Glyph 2-bromo-LSD), a Glyphed oral prodrug of the non-hallucinogenic LSD analog 2-bromo-LSD, in preclinical studies for depressive disorders, including treatment-resistant depression, or TRD, post-traumatic stress disorder, or PTSD, and headache disorders.

There can be no assurance that the Company’s research and development efforts will be successfully completed, that any product candidates developed will obtain necessary government regulatory approval, or that any products, if approved, will be commercially viable. The Company operates in an environment of rapid technological innovation and substantial competition from pharmaceutical and biotechnology companies. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will realize significant product revenue from product sales.

Reverse stock split

On April 24, 2026, in anticipation of our initial public offering ("IPO"), the Company effected a 1-for-3.1407 reverse stock split of its issued and outstanding shares of common stock and a proportional adjustment to the existing conversion ratios of each series of the Company’s convertible preferred stock. The par value and authorized number of shares of common stock and convertible preferred stock were not adjusted as a result. All share and per share amounts for all periods presented in the accompanying condensed consolidated financial statements and notes thereto have been adjusted retroactively, where applicable, to reflect the effect of the reverse stock split.

Initial public offering

During the second quarter of 2026, the Company completed its IPO, in which the Company sold an aggregate of 14,446,658 shares of its common stock, including 286,568 shares issued pursuant to the exercise of the underwriters' overallotment option, at a public offering price of $18.00 per share resulting in aggregate net proceeds of approximately $238.7 million, after deducting underwriter discounts, commissions and other estimated offering expenses.

Immediately prior to the closing of the IPO, the Company's outstanding convertible preferred stock automatically converted into 36,272,475 shares of common stock. Following the closing of the IPO, no shares of convertible preferred stock were outstanding. In connection with the closing of the IPO, the Company's certificate of incorporation was amended and restated to authorize 700,000,000 shares of common stock, including 500,000,000 shares of voting common stock and 200,000,000 shares of non-voting common stock, par value $0.0001 per share and 10,000,000 shares of undesignated preferred stock, par value $0.0001 per share.

Liquidity

In accordance with Accounting Standards Update (“ASU”) 2014-15, Disclosure of Uncertainties About an Entity’s Ability to Continue as a Going Concern (Subtopic 205-40), the Company has evaluated whether there are conditions and events that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the date the condensed consolidated financial statements are issued. The accompanying condensed consolidated financial statements have been prepared on a going-concern basis, which contemplates the realization of assets and satisfaction of liabilities in the normal course of business.

Since inception, the Company has incurred significant operating losses. During the three months ended March 31, 2026 and 2025, the Company had a net loss of $25.4 million and $13.1 million, respectively. As of March 31, 2026, the Company had an accumulated deficit of $139.5 million. The Company has not generated any revenue from product sales and does not expect to generate revenue from sales of products in the near term, if at all. The Company expects to incur significant expenses and operating losses for the foreseeable future as it advances its product candidates into and through clinical development and continues to develop additional product candidates. As such, the Company expects our research and development and general and administrative costs to continue to increase significantly, including the costs associated with operating as a public company. The Company’s ability to access capital when needed is not assured and, if capital is not available to the Company when, and in the amounts needed, the Company may be required to significantly curtail, delay, or discontinue one or more of its research or development programs or the commercialization of any product candidate, or be unable to expand its operations, or otherwise capitalize on the Company’s business opportunities, as desired, which could materially harm the Company’s business, financial condition, and results of operations.

To date, prior to the Company's initial public offering, the Company has funded its operations with the aggregate gross proceeds of $326.1 million from the Series A and Series B Financings. During the second quarter of 2026, the Company raised aggregate net proceeds of $238.7 million from the sale of shares of common stock in its initial public offering, after deducting underwriter discounts, commissions and other estimated offering expenses. The Company believes that its existing cash, cash equivalents and investments of $212.6 million as of March 31, 2026, together with the additional proceeds received from the IPO, will be sufficient to allow the Company to fund operations at least twelve months from the date that of these condensed consolidated financial statements are issued.

Basis of Presentation

The accompanying condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America, or GAAP. These condensed consolidated financial statements include the accounts of Seaport Therapeutics, Inc. and its wholly owned subsidiaries. All intercompany transactions and balances have been eliminated in consolidation.

As of March 31, 2026, PureTech continued to provide various corporate services under the transition services agreement, or the TSA, which was initially set to terminate one year following the date of the Asset Transfer Agreement. In 2025, the TSA was amended to extend through July 2026 to provide ad-hoc support; however, the total value of the services are not material and the agreement was cancelled in April 2026.

2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

There have been no significant changes from the significant accounting policies and estimates disclosed in Note 2 of the “Notes to Consolidated Financial Statements” in the audited consolidated financial statements for the year ended December 31, 2025 and notes thereto, included in the Company’s IPO final prospectus filed pursuant to Rule 424(b) (4) under the Securities Act with the SEC on May 1, 2026.

Unaudited interim financial information

The accompanying condensed consolidated balance sheet as of March 31, 2026, and the condensed consolidated statements of operations and comprehensive loss, condensed consolidated statements of convertible preferred stock and stockholders' deficit and condensed consolidated statements of cash flows for the three months ended March 31, 2026 and 2025 are unaudited. The condensed consolidated interim financial statements have been prepared on the same basis as the December 31, 2025 and 2024 audited financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments necessary for the fair statement of the Company's condensed consolidated financial statements as of March 31, 2026. The results for the three months ended March 31, 2026 are not necessarily indicative of results to be expected for the year ending December 31, 2026, or for any other subsequent period.

Cash, Cash Equivalents, and Restricted Cash

The Company considers all highly liquid investments that are readily convertible into cash with original maturities of three months or less at the date of purchase to be cash equivalents. The Company invests excess cash primarily in overnight cash sweeps and money market funds which are highly liquid and have high credit ratings. Such investments are subject to minimal credit and market risks. The Company classifies all cash of which use is limited by contractual provisions as restricted cash. Restricted cash is recorded on the condensed consolidated balance sheet within other non-current assets and includes amounts held as a security deposit for a letter of credit in connection with leased facilities and its corporate card program.

The following table summarizes the Company’s cash, cash equivalents, and restricted cash (in thousands):


	March 31,		December 31,
	2026		2025
Cash and cash equivalents	$	52,909	$	46,042
Restricted cash within other non-current assets		454		454
Total cash, cash equivalents, and restricted cash per the condensed consolidated statements of cash flows	$	53,363	$	46,496

Deferred Offering Costs

The Company capitalizes certain legal, professional, accounting and other third-party fees that are directly associated with in-process equity financings as deferred offering costs until such financings are consummated. After consummation of an equity financing, these costs are recorded as a reduction of the proceeds from the offering, either as a reduction of the carrying value of the convertible preferred stock or in stockholders’ equity (deficit) as a reduction of additional paid-in capital generated as a result of the offering. Should the in-process equity financing be abandoned or delayed the deferred offering costs would be expensed immediately as a charge to operating expenses in the condensed consolidated statements of operations and comprehensive loss. The Company recorded deferred offering costs of $2.2 million and $1.2 million within other non-current assets as of March 31, 2026 and December 31, 2025.

Government Grants

The Company received an award to perform research activities by a United States government agency which provides the Company with payments to reimburse research and development expenses. The Company accounts for government awards under ASC 832, Government Assistance. For awards related to income, the Company recognizes amounts earned under government awards when it is deemed probable that the Company will comply with the conditions attached to the government award and the government award will be received. The Company recognizes amounts earned under government awards as a reduction of research and development expense as the qualifying research expense is incurred, and records a corresponding receivable within prepaid and other current assets on its condensed consolidated balance sheet.

Net Loss per Share

The Company applies the two-class method when computing net loss per share attributable to common stockholders as the Company has issued shares that meet the definition of participating securities. The two-class method determines net loss per share for each class of common and participating securities according to dividends declared or accumulated and participation rights in undistributed earnings. The two-class method requires income (loss) available to common stockholders for the period to be allocated between common and participating securities based upon their respective rights to share in the undistributed earnings as if all income (loss) for the period had been distributed. The Company considers its convertible preferred stock to be participating securities as, in the event a dividend is paid on common stock, the holders of convertible preferred stock would be entitled to receive dividends on a basis consistent with the common stockholders. There is no allocation required under the two-class method during periods of loss since the participating securities do not have a contractual obligation to share in the losses.

Basic net loss per share is computed by dividing the net loss in each period by the weighted average number of shares of common stock outstanding during such period, excluding potentially dilutive common shares. Diluted net loss per share is computed similarly to basic net loss per share except that the denominator is increased to include the number of additional shares of common stock that would have been outstanding if the potential shares of common stock had been issued and if the additional shares of common stock were dilutive.

Recently Adopted Accounting Pronouncements

In December 2025, the FASB issued ASU 2025-10, Government Grants (Topic 832): Accounting for Government Grants Received by Business Entities, which adds guidance to ASC 832 on the recognition, measurement, and presentation of government grants. In developing the ASU’s recognition and measurement framework, the FASB largely leveraged the guidance in IAS 20, to which many for-profit entities that apply U.S. GAAP have historically analogized when accounting for government grants. The ASU is effective for fiscal years beginning after December 15, 2028, including interim periods within those fiscal years. Early adoption is permitted. The Company early adopted ASU 2025-10 prospectively on January 1, 2026. There was not a material impact on the Company’s condensed consolidated financial statements as a result of this adoption.

Recently Issued Accounting Standards Updates Not Yet Adopted

From time to time, new accounting pronouncements are issued by the FASB, or other standard-setting bodies that are adopted by Seaport as of the specified effective date. The Company qualifies as an ‘‘emerging growth company’’ as defined in the Jumpstart Our Business Startups Act of 2012 and has elected not to ‘‘opt out’’ of the extended transition related to complying with new or revised accounting standards, which means that when a standard is issued or revised and it has different application dates for public and non-public companies, the Company can adopt the new or revised standard at the time non-public companies adopt the new or revised standard and can do so until such time that the Company either (i) irrevocably elects to ‘‘opt out’’ of such extended transition period or (ii) no longer qualifies as an emerging growth company. The Company may choose to early adopt any new or revised accounting standards whenever such early adoption is permitted for non-public companies. Unless otherwise discussed, the Company believes that the impact of recently issued standards that are not yet effective will not have a material impact on its financial position or results of operations upon adoption.

In November 2024, the FASB issued ASU 2024-03, Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses, or ASU 2024-03, which is intended to provide more detailed information about specified categories of expenses (purchases of inventory, employee compensation, depreciation, and amortization) included in certain expense captions presented on the statement of operations. The guidance in ASU 2024-03 is effective for fiscal years beginning after December 15, 2026. Early adoption is permitted. The amendments may be applied either (1) prospectively to financial statements issued for periods after the effective date of ASU 2024-03 or (2) retrospectively to all prior periods presented in the financial statements. The Company is currently evaluating the impact that the adoption of ASU 2024-03 may have on its consolidated financial statements and disclosures for fiscal years beginning after December 15, 2026.

3. PREPAID EXPENSES AND OTHER CURRENT ASSETS

Prepaid expenses and other current assets consisted of the following (in thousands):


	March 31,		December 31,
	2026		2025
Prepaid research and development	$	1,187	$	3,026
Interest receivable		1,383		1,733
Australia research and development tax credit receivable		1,894		1,296
Prepaid other		1,272		1,192
Prepaid expenses and other current assets	$	5,736	$	7,247

4. FAIR VALUE MEASUREMENTS

The following table sets forth by level, within the fair value hierarchy, the financial assets, and liabilities carried at fair value on a recurring basis (in thousands):


	March 31, 2026
	Total		Quoted prices in active markets for identical assets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)
Cash equivalents:
Money market funds	$	52,287	$	52,287	$	—	$	—
Investments:
U.S. treasuries		159,733		—		159,733		—
Total financial assets	$	212,020	$	52,287	$	159,733	$	—

	December 31, 2025
	Total		Quoted prices in active markets for identical assets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)
Cash equivalents:
Money market funds	$	45,710	$	45,710	$	—	$	—
Investments:
U.S. treasuries		187,611		—		187,611		—
Total financial assets	$	233,321	$	45,710	$	187,611	$	—

As of March 31, 2026 and December 31, 2025, the Company’s cash equivalents consisted of money market funds which are classified as Level 1 financial assets, as these assets are valued using quoted market prices in active markets without any valuation adjustment. As of March 31, 2026 and December 31, 2025, the Company's investments consisted of United States treasuries, which are classified as Level 2 financial assets. The Company estimates the fair value of the investments by taking into consideration valuations obtained from third-party pricing sources. As of March 31, 2026 and December 31, 2025, the Company had no financial liabilities that required fair value measurement. As of March 31, 2026, there were no securities in an unrealized loss position for more than twelve months.

During the three months ended March 31, 2026, there were no transfers or reclassifications between fair value measurement levels of assets. The carrying amounts reflected in the condensed consolidated balance sheets for prepaid expenses and other current assets, accounts payable, related party payable and accrued expenses and other current liabilities approximate fair value due to their short-term nature.

5. INVESTMENTS

The following table summarizes the Company’s investments held (in thousands):


	March 31, 2026
	Amortized Cost		Unrealized Holding Gains		Unrealized Holding Losses			Fair Value
Short-term investments:
U.S. Treasuries	$	129,924	$	—	$	(228	)	$	129,696
Long-term investments:
U.S. Treasuries		30,061		—		(24	)		30,037
Total financial assets	$	159,985	$	—	$	(252	)	$	159,733

	December 31, 2025
	Amortized Cost		Unrealized Holding Gains		Unrealized Holding Losses			Fair Value
Short-term investments:
U.S. Treasuries	$	169,662	$	279	$	—		$	169,941
Long-term investments:
U.S. Treasuries		17,639		31		—			17,670
Total financial assets	$	187,301	$	310	$	—		$	187,611

As of March 31, 2026, the Company’s investments were in net unrealized loss position of $0.3 million. These amounts are included in other comprehensive income (loss) in the condensed consolidated statements of operations and comprehensive loss. The Company determined that there was no material credit risk associated with its investments as of March 31, 2026. As of March 31, 2026, the Company’s investments had remaining maturities of two years or less.

As of December 31, 2025, the Company’s investments were in net unrealized gain position of $0.3 million. These amounts are included in other comprehensive income (loss) in the condensed consolidated statements of operations and comprehensive loss. As of December 31, 2025, there were no investments in an unrealized loss position. The Company determined that there was no material credit risk associated with its investments as of December 31, 2025. As a result, the Company did not record any charges for credit-related impairments for its investments during the year ended December 31, 2025. As of December 31, 2025, the Company’s investments had remaining maturities of two years or less.

6. PROPERTY AND EQUIPMENT, NET

Property and equipment, net consisted of the following (in thousands):


	March 31,			December 31,
	2026			2025
Lab equipment	$	943		$	943
Leasehold improvements		432			432
Furniture and fixtures		26			26
Total		1,401			1,401
Less: Accumulated depreciation		(1,015	)		(989	)
Property and equipment, net	$	386		$	412

Depreciation expense was $26 thousand and $36 thousand for the three months ended March 31, 2026 and 2025, respectively.

7. ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES

Accrued expenses and other current liabilities consisted of the following (in thousands):


	March 31,		December 31,
	2026		2025
Accrued research and development expense	$	3,694	$	2,639
Accrued personnel and bonus expense		1,712		5,192
Accrued professional and legal fees		409		260
Accrued other		2,011		1,040
Accrued expenses and other current liabilities	$	7,826	$	9,131

8. LICENSE and collaboration AGREEMENT

Monash License Agreement

In April 2024, PureTech Health exclusively assigned to the Company, and the Company assumed all rights and obligations under a license agreement between PureTech Health and Monash University entered into in August 2017, or the Original License Agreement. In March 2025, the Company entered into an amended and restated license agreement with Monash University, which amended and restated the Original License Agreement, or the Monash License Agreement.

Pursuant to the Monash License Agreement, Monash University grants the Company (i) a worldwide, exclusive, sublicensable license under certain Monash University intellectual property rights, including patent rights related to the Glyph platform, or the Licensed Patents, know-how, and intellectual property stemming from joint research and development activities, for the purpose of developing and commercializing products in all fields with one exception, (ii) a worldwide, non-exclusive, sublicensable license under certain background technology and certain other intellectual property strictly to the extent necessary to exercise the license described in subclause (i) above, and (iii) a first right and an exclusive option to obtain an exclusive license to any invention generated by Monash University outside of the Licensed Patents and pertaining to certain prodrug technology. Additionally, the Company and Monash University agreed to collaborate in conducting research and development activities.

Under the Monash License Agreement, the Company has agreed to use reasonable commercial endeavors to (i) develop at least one Licensed Product, (ii) seek regulatory approval for at least one Licensed Product, and (iii) after receipt of such regulatory approval in the United States or Europe, promote, and develop the sale of at least one Licensed Product in such territory. Monash University agrees to provide reasonable technical assistance and advice based on Monash University’s know-how relating to the technology licensed under the Monash License Agreement. The Company granted Monash University a non-exclusive, perpetual, royalty-free license under the Licensed Patents, related know-how, and intellectual property stemming from joint research and development activities solely for academic, teaching, and non-commercial collaborative research uses, which includes the right to sublicense for non-commercial collaborative research to other academic institutions or non-commercial research entities.

As consideration for the licenses granted by Monash University, the Company is required to pay Monash University: (i) between 3% and 5% on net sales per calendar year (subject to certain reductions); (ii) a low-double digit percentage of any net income received under a sublicense (subject to a license payment stacking reduction) with the percentage varying based on the development stage of the Licensed Products at the time the sublicense is granted during the term of the Monash License Agreement; (iii) an agreed upon research funding amount to progress mutually agreed research and development or commercialization activities; (iv) a mid-five-figure annual maintenance fee during the term of the agreement commencing on the third anniversary of the execution date of the Original License Agreement until the first commercial sale of a Licensed Product creditable against net income sharing, royalties, and milestone payments; (v) milestone payments in the event of successful development milestones of up to $1.075 million per Licensed Product for the first three Licensed Products; and (vi) milestone payments in the event of successful commercial milestones of up to $7.25 million per Licensed Product for the first three Licensed Products. The Company is also obligated to (a) pay all costs incurred for the prosecution and maintenance of the Licensed Patents and patent filings stemming from collaboration activities and (b) reimburse Monash University for all patent prosecution costs of the Licensed Patents prior to the execution date of the Original License Agreement.

The Monash License Agreement commenced on the execution date of the Original License Agreement and will expire seven years after the last of the Licensed Patents expires, unless terminated earlier. Either party may terminate for due cause, including for material breach and bankruptcy. Monash University may terminate if the Company fails to meet its diligence requirements. Either party may terminate the Monash License Agreement if the Company determines that the activities are no longer commercially viable.

The Monash License Agreement was determined to represent an asset acquisition, as the acquired licenses and intellectual property did not meet the definition of a business. All upfront consideration paid in exchange for the Monash License Agreement was expensed as research and development upon execution of the agreement, as the Licensed Patents and intellectual property was determined to represent in-process research and development with no alternative future use.

Prior to the formation of the Company, PureTech paid $0.2 million in development milestones under the Monash License Agreement. Since the formation of the Company, the Company paid $0.1 million in development milestones under the agreement. No milestones were paid by the Company under the Monash License Agreement during the three months ended March 31, 2026.

Monash Collaboration Agreement and ARPA-H Award

In March 2026, the Advanced Research Projects Agency for Health (“ARPA-H”) granted the Company and Monash University an award for research under the Groundbreaking Lymphatic Interventions and Drug Exploration (“GLIDE”) program (the "Award Agreement"). The Award Agreement provides for total funding of up to $15.2 million, which includes committed funding of $3.5 million for the first phase of research under the award and uncommitted funding of up to $11.7 million for the second phase of the research plan under the award. The funding for the second phase is not currently committed and is subject to mutual agreement by the parties; if exercised, the parties will execute a contract modification at that time. The initial term of the Agreement is 48 months. The Agreement may be terminated by either party upon 60 days’ written notice, in which case the parties are required to negotiate in good faith to resolve any outstanding matters.

Payments under the Award Agreement are fixed and are earned upon the achievement of defined milestones. As of March 31, 2026, no milestones have been earned under the Award Agreement. During the three months ended March 31, 2026, the Company recognized immaterial amounts under the Award Agreement as a reduction of research and development expense.

9. CONVERTIBLE PREFERRED STOCK

The Company has issued Series A-1 convertible preferred stock, or the Series A-1 Preferred Stock, Series A-2 convertible preferred stock, or the Series A-2 Preferred Stock, and Series B convertible preferred stock, or the Series B Preferred Stock, and collectively with the Series A-1 Preferred Stock and Series A-2 Preferred Stock, the Preferred Stock.

Series A-1 and Series A-2 Preferred Stock

In April 2024, the Company issued to PureTech LYT, a wholly owned subsidiary of PureTech, 40,000,000 shares of its Series A-1 Preferred Stock, as part of the consideration for the assets contributed to the Company as part of the Asset Transfer Agreement. No value was assigned to the Series A-1 Preferred Stock as it represented consideration paid as part of a common control transaction. See Note 1—Nature of Business and Basis of Presentation, for further disclosure of the Asset Transfer Agreement.

Concurrently, upon the issuance of the Series A-1 Preferred Stock to PureTech LYT, the Company entered into a Series A-2 Preferred Stock Purchase Agreement, or the Series A-2 Financing, with PureTech LYT and other third-party investors pursuant to which the Company issued and sold 26,342,102 shares of its Series A-2 Preferred Stock at a price of $3.80 per share for gross aggregate proceeds of $100.1 million.

Series B Preferred Stock

In October 2024, the Company entered into a stock purchase agreement with new and existing investors, or the Series B Financing, pursuant to which the Company issued and sold an aggregate amount of 47,578,934 shares of its Series B Preferred Stock at a purchase price of $4.75 per share, for gross aggregate proceeds of $226.0 million.

Upon issuance of the Preferred Stock, the Company assessed the embedded conversion and liquidation features of the securities and determined that such features did not require the Company to separately account for these features.

As of March 31, 2026 and December 31, 2025, Preferred Stock consisted of the following (in thousands, except share and per share amounts):


	Preferred Stock Authorized		Preferred Stock Issued and Outstanding		Carrying Value		Liquidation Preference		Conversion Price per Share		Common Stock Issuable Upon Conversion
Series A-1 Preferred Stock		40,000,000		40,000,000	$	—	$	4,000	$	0.32		12,736,014
Series A-2 Preferred Stock		26,342,102		26,342,102		99,757		100,100	$	11.94		8,387,331
Series B Preferred Stock		47,578,938		47,578,934		225,571		226,000	$	14.92		15,149,130
Total Preferred Stock		113,921,040		113,921,036	$	325,328	$	330,100				36,272,475

As of March 31, 2026, the holders of the Preferred Stock have the following rights and preferences:

Voting

The holders of the Preferred Stock are entitled to vote, together with the holders of common stock, as a single class, on all matters submitted to the shareholders for a vote and are entitled to the number of votes equal to the number of shares of common stock into which the Preferred Stock would convert on the record date for determination of shareholders entitled to vote. The holders of the Preferred Stock generally vote together as a single class with holders of common stock except that, (i) the holders of Series A-1 Preferred Stock, exclusively and voting together as a separate class on an as converted basis, shall be entitled to elect two (2) directors of the Company, each, a Series A-1 Director, (ii) the holders of record of the shares of Series A-2 Preferred Stock, exclusively and voting together as a separate class on an as converted basis, shall be entitled to elect two (2) directors of the Company, each, a Series A-2 Director, (iii) the holders of record of the shares of Series B Preferred Stock, exclusively and voting together as a separate class on an as converted basis, shall be entitled to elect one (1) director of the Company, or the Series B Director and, together with the Series A-1 Directors and Series A-2 Directors, each, a Preferred Director.

Further, a majority vote of the holders of the Company's Preferred Stock is required to, among others, liquidate or dissolve the Company, amend the certificate of incorporation or bylaws, reclassify common stock or establish another class of capital stock, create shares that would rank senior to or authorize additional shares of Preferred Stock, declare a dividend or make a distribution, or change the authorized number of directors constituting the board of directors.

Dividends

The holders of the Preferred Stock are entitled to participate in any dividends payable to common stockholders on an as converted basis and have priority over the payment of dividends to holders of common stock.

In the case of a dividend on common stock or any class of stock that is convertible into common stock, the dividend per share of Preferred Stock would equal the product of (A) the dividend payable on each share of such class or series as if all shares of such class or series had been converted into common stock and (B) the number of shares of common stock issuable upon conversion of such share of Preferred Stock. In the case of a dividend on any class or series that is not convertible into common stock, the dividend per share of Preferred Stock would be determined by (A) dividing the amount of dividend payable on each share of such class or series of capital stock by the original issue price of such class or series and (B) multiplying such fraction by the original issue price of the applicable class or series of Preferred Stock.

Conversion

Each outstanding share of Preferred Stock is convertible, at any time, at its holder’s discretion, and without the payment of additional consideration, into such whole number of fully paid, non-assessable shares of common stock, at the applicable conversion ratio then in effect. The conversion price for each share of Preferred Stock shall initially be equal to the original issuance price for such series of Preferred Stock and is subject to standard anti-dilutive adjustments for share splits and similar transactions. In the event certain conditions are not met prior to March 31, 2026, the conversion price of the Series B Preferred Stock will be reduced to $3.80. In July 2025, the Company satisfied the applicable condition, thereby eliminating the conversion price reduction contingency.

Each outstanding share of Preferred Stock shall automatically be converted into fully-paid, non-assessable shares of common stock upon the earliest to occur of (i) the consummation of a qualified initial public offering at a public offering price of at least $5.70 per share, in a firm commitment resulting in at least $100.0 million of gross proceeds or (ii) the date specified by vote or written consent of the holders of at least a majority of the outstanding shares of the Preferred Stock, voting together as a single class on an as-converted basis, and the holders of a majority of the outstanding shares of Series A-2 Preferred Stock and Series B Preferred Stock, which majority must include at least one new investor from the Series B Financing that holds at least 2,100,000 shares of Series B Preferred Stock,

voting together as a single class on an as-converted basis, or the Requisite Holders, and the holders of at least 65% of the then-outstanding shares of Series B Preferred Stock, or the Series B Majority. All outstanding convertible preferred stock was converted into common stock immediately prior to the closing of the Company’s IPO.

There shall be no adjustment in the conversion price of the Preferred Stock as a result of the issuance or deemed issuance of additional shares of the Company’s common stock if the Company receives written notice from the holders of at least a majority of the then outstanding shares of Preferred Stock, voting together as a single class, and, solely in the respect of an adjustment in the conversion price of the Series B Preferred Stock, the Series B Majority, agreeing that no such adjustment shall be made as the result of the issuance or deemed issuance of additional shares of the Company’s common stock.

Liquidation

In the event of any voluntary or involuntary liquidation, dissolution, or winding up of the Company, or upon the occurrence of a Deemed Liquidation Event (as defined below), the holders of shares of Preferred Stock then outstanding shall be entitled, on a pari passu basis among the series of Preferred Stock, to be paid out of the assets or funds of the Company available for distribution to stockholders before any payment is made to the holders of common stock. The holders of Preferred Stock are entitled to an amount per share equal to the greater of (i) the original issue price for such series, plus any dividends declared but unpaid thereon, or (ii) the amount that would have been payable had all shares of each series of Preferred Stock been converted into common stock immediately prior to such liquidation, dissolution, winding up or Deemed Liquidation Event. After the payment in full of the Preferred Stock preference amount, the remaining assets of the Company available for distribution to stockholders shall be distributed among the holders of common stock on a pro rata basis.

Each of the following events shall be considered a “Deemed Liquidation Event,” unless the Requisite Holders, elect otherwise; a merger, consolidation, statutory conversion, transfer, domestication, continuance involving the Company or a subsidiary, or a sale, lease, or transfer of substantially all of the assets of the Company.

Redemption

The Preferred Stock does not have any redemption rights, except for the contingent redemption upon the occurrence of a Deemed Liquidation Event.

10. COMMON STOCK

The voting, dividend, and liquidation rights of the holders of the Company’s common stock are subject to and qualified by the rights, powers, and preferences of the holders of the Preferred Stock set forth above. Each share of common stock entitles the holder to one vote, together with the holders of the Preferred Stock, on all matters submitted to the stockholders for a vote. The holders of common stock are entitled to receive dividends, if any, as declared by the Company’s board of directors, subject to the preferential dividend rights of Preferred Stock. As of March 31, 2026, no dividends have been declared or paid.

As of March 31, 2026, the Company had authorized 159,070,000 shares of common stock, of which 2,595,342 were issued and outstanding, including 121,612 unvested shares of restricted common stock that are subject to service-based vesting as of March 31, 2026.

11. STOCK-BASED COMPENSATION

2024 Equity Incentive Plan

The 2024 Equity Incentive Plan, or the 2024 Plan, was approved by the Company’s subsidiary’s Board and Stockholders and became effective for the Company in April 2024 and was subsequently amended in April 2024 and October 2024.

Under the 2024 Plan, the Company can issue incentive stock options, stock appreciation rights, restricted stock, restricted stock units, and other stock-based awards to employees, directors, and consultants of the Company. The 2024 Plan is administered by the Company’s Board of Directors, or by a committee at the discretion of the Board of Directors. The exercise prices, vesting, and other restrictions are determined at the discretion of the Board of Directors, or its committee if so delegated, except that exercise prices of each stock option shall not be less than 100% of the fair market value of the Company’s common stock and that each stock option term cannot exceed 10 years. The Company’s Board of Directors determines the fair market value of the Company’s common stock, taking into consideration its most recently available valuation of common stock performed by third parties as well as additional factors which may have changed since the date of the most recent contemporaneous valuation through the date of grant.

A total of 3,184,003 shares of common stock were initially reserved for issuance under the 2024 Plan, and it was subsequently amended to allow for the issuance of up to 12,292,486 shares of common stock. As of March 31, 2026, there were 866,126 awards available for future grants under the 2024 Plan. Shares of common stock underlying any awards that are forfeited, canceled, or reacquired by the Company prior to vesting will again be available for the grant of awards under the 2024 Plan. Through the completion of its IPO, the Company granted additional equity awards to certain individuals to maintain in total a 12.5% ownership on a fully diluted basis as specified by underlying agreements. See Note 18—Subsequent Events, for further disclosure related to the equity grants associated with the IPO.

The vesting periods for stock options issued under the 2024 Plan generally vest over four years with a one-year cliff and equal monthly installments thereafter and may be subject to accelerated vesting. Performance-based options vest in three annual installments that are contingent upon the achievement of the Company’s annual goals. For restricted stock awards, the vesting periods can vary and may contain accelerated vesting that would result in unvested shares becoming fully vested upon the occurrence of certain events.

2024 Plan Stock Option Activity

The following is a summary of the Company’s stock option award activity under the 2024 Plan during the three months ended March 31, 2026:


	Number of Stock Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2025		8,569,619		$	4.60		8.67	$	28,669
Granted		1,038,909			10.09		—		—
Exercised		—			—		—		—
Forfeited		(289,028	)		4.64		—		—
Expired		—			—		—		—
Outstanding at March 31, 2026		9,319,500		$	5.30		8.43	$	47,390
Vested and expected to vest at March 31, 2026		9,319,500		$	5.30		8.43	$	47,390
Exercisable at March 31, 2026		5,688,843		$	4.22		8.01	$	33,744

The table above excludes 152,515 of the 228,771 performance-based options which have an exercise price of $7.39 per share, that were approved to be issued by the Company’s Board of Directors in December 2024, but have not yet been deemed granted from an accounting perspective as of March 31, 2026. During the three months ended March 31, 2026, 76,256 of these performance-based options were determined to be granted from an accounting perspective and the company recorded stock compensation expense of $0.6 million.

The Company utilized the Black-Scholes option-pricing model for estimating the fair value of the stock options issued under the 2024 Plan on each grant date. The following table presents the ranges of assumptions used by the Company in the Black-Scholes option-pricing model during the three months ended March 31, 2026 and 2025:


	March 31,
	2026	2025
Expected term (in years)	5.50 - 6.11 years	5.85 - 6.08 years
Risk-free interest rate	3.59% - 3.86%	3.93% - 4.39%
Volatility	93.71% - 94.23%	90.74% - 91.63%
Dividend yield	0.00%	0.00%

The weighted-average grant date fair value of options granted during the three months ended March 31, 2026 and 2025 was $9.18 and $5.65 per share, respectively. The aggregate intrinsic value is calculated as the difference between the exercise price and the fair value of the Company’s common stock as of each period end or exercise date. There were no stock options exercised during the three months ended March 31, 2026 and 2025.

As of March 31, 2026, there was $22.4 million in unrecognized stock-based compensation expense associated with issued and outstanding service-based stock options, which is expected to be recognized over a weighted-average period of 1.3 years and is partially subject to future accelerated vesting upon the close of an initial public offering.

2024 Plan Restricted Stock Awards

The Company has granted restricted stock awards to certain members of the Company’s Board of Directors and Chief Executive Officer. Of the total 1,990,001 restricted stock awards granted: (i) 796,000 have service-based vesting in equal monthly installments over a three-year period, of which 50% of the unvested amount was subject to accelerated vesting upon the close of the Series B Financing and 50% of any unvested amounts is subject to future acceleration upon the close of an initial public offering; and (ii) 1,194,001 have performance based vesting which vested in full upon the close of the Series B Financing. The company completed an IPO in May 2026, see Note 18—Subsequent Events, for further disclosure related to the equity awards that vested upon the IPO.

The following is a summary of the Company’s restricted stock award activity under the 2024 Plan during the three months ended March 31, 2026:


	Number of Units			Weighted- Average Fair Value
Unvested at December 31, 2025		154,778		$	3.05
Vested		(33,166	)		3.05
Unvested at March 31, 2026		121,612		$	3.05

No restricted stock awards were granted during the three months ended March 31, 2026 and 2025. The total fair value of the restricted stock awards that vested during the three months ended March 31, 2026 and 2025 was $0.1 million and $0.1 million, respectively, and the total stock-based compensation associated with the restricted stock awards during the three months ended March 31, 2026 and 2025 was $0.1 million and $0.1 million, respectively. As of March 31, 2026, there was $0.4 million in unrecognized stock-based compensation expense associated with issued and outstanding restricted stock awards, which is expected to be recognized over a weighted-average period of 0.5 years.

Stock-Based Compensation Expense

The following table represents stock-based compensation expense recorded in the Company’s condensed consolidated statements of operations and comprehensive loss (in thousands):


	Three Months Ended March 31,
	2026		2025
Research and development	$	891	$	497
General and administrative	$	1,678		1,122
Stock-based compensation expense	$	2,569	$	1,619

12. INCOME TAXES

The Company's effective tax rates were (2.1)% and (0.2)% for the three months ended March 31, 2026 and 2025, respectively. The effective tax rate in 2026 differs from 2025 primarily due to additional tax expense recorded in Australia. The income tax provision and effective tax rate are driven primarily by a valuation allowance in the United States, partially offset by income tax in Australia.

The Company maintains a valuation allowance on the majority of its deferred tax assets, and it has concluded that it is more likely than not that the deferred assets will not be utilized.

13. LEASES

In October 2024, the Company entered into an operating lease for office space in Boston, Massachusetts, which commenced in December 2024 and has an initial lease term that continues through October 20, 2030, with no options to extend. In conjunction with entering into the lease, the Company paid a security deposit of $0.2 million in the form of a letter of credit, which is recorded as restricted cash within other non-current assets on the Company’s condensed consolidated balance sheets as of March 31, 2026 and December 31, 2025.

In December 2024, the Company entered into a laboratory lease agreement with a third party for lab space located in Boston, Massachusetts. The lease commenced in January 2025 and is for an initial term of 24 months from the commencement date. In March 2026, the Company exercised its option to extend the lease for an additional 12 months. The modification resulted in an increase to the operating lease right of use asset and lease liability of $0.6 million.

14. COMMITMENTS AND CONTINGENCIES

Legal Matters

The Company, from time to time, may be involved with lawsuits arising in the ordinary course of business. The Company is not involved in any pending legal proceedings that it believes could have a material adverse effect on its financial condition, results of operations, or cash flows.

Contracts

The Company enters into contracts in the normal course of business with various third parties for preclinical research studies, clinical trials, testing, manufacturing, and other services. These contracts generally provide for termination upon notice and are cancellable without significant penalty or payment, and do not contain any minimum purchase commitments.

License and Other Agreements

The Company is obligated to make fixed and contingent payments under the Asset Transfer Agreement and Monash License Agreement, See Note 8—Monash License Agreement, for further disclosure of the Monash license agreement.

The Asset Transfer and Series A Financing

On April 8, 2024, or the Asset Transfer Date, the Company entered into an asset transfer agreement, as amended in December 2025, or the Asset Transfer Agreement with PureTech Health LLC, or PureTech Health, and PureTech LYT, pursuant to which PureTech Health and PureTech LYT, agreed to contribute, convey, assign, transfer, and deliver to the Company all of its right, title, and interest in, to and under the assets related to its Glyph technology and products, or the Asset Transfer. As consideration, the Company issued to PureTech LYT 40,000,000 shares of its Series A-1 convertible preferred stock and 302,161 shares of its common stock on the Asset Transfer Date, and also agreed to contingent payments to PureTech upon successful development and commercialization of products developed using the Glyph platform, each of which is referred to as a Seaport Glyph Product, including; milestone payments of up to an aggregate of $10.0 million for the first product covered by assets transferred through the Asset Transfer Agreement, or the Seaport Glyph Product, of $2.0 million for the first patient dosed in the first phase 3 clinical trial, $4.0 million for the first commercial sales in the United States, $2.0 million for the first commercial sale in a major European market, and $2.0 million for the first commercial sale in Japan, and for each subsequent Seaport Glyph Product, the Company has agreed to make milestone payments of $1.0 million for the first patient dosed in the first phase 3 clinical trial, $2.0 million for the first commercial sale in the United States, $1.0 million for the first commercial sale in a major European market, and $1.0 million for the first commercial sale in Japan. In addition, the Company is obligated to pay royalties between 3% and 5% on the annual net sales of each Seaport Glyph Product as follows: less than $500 million: 3%; $500 million to $1 billion: 3.5%; $1 billion to $2.5 billion: 4%; $2.5 billion to $3.5 billion: 4.5%; $3.5 billion or greater: 5% and a percentage of net income generated by the Company from third parties on any products licensed under the Glyph intellectual property which was transferred as part of the Asset Transfer Agreement.

Guarantees and Indemnification

In the ordinary course of business, the Company may provide indemnification of varying scope and terms to vendors, lessors, business partners and other parties with respect to certain matters including, but not limited to, losses arising out of breach of such agreements or from intellectual property infringement claims made by third parties. In addition, the Company has entered into indemnification agreements with all members of the board of directors that will require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is, in many cases, unlimited. To date, the Company has not incurred any material costs as a result of such indemnifications. The Company is not aware of any claims under indemnification arrangements that could have a material effect on its financial position, results of operations, or cash flows, and it has not accrued any liabilities related to such obligations in its condensed consolidated financial statements as of March 31, 2026 and December 31, 2025 and for the three months ended March 31, 2026 and 2025.

Leases

See Note 13—Leases, for information related to the Company’s lease obligations.

15. Segments

The Company has one operating and reportable segment focused on inventing and developing novel medicines for patients with depression, anxiety, and other debilitating neuropsychiatric disorders using the Company's proprietary Glyph™ Platform.

The chief operating decision-maker, or CODM, manages the Company’s operations on a consolidated basis, and assesses performance based on consolidated net loss that is reported on the condensed consolidated statements of operations and comprehensive loss. The CODM makes decisions about allocating resources and assessing performance for the entire company. The measure of segment assets is reported on the condensed consolidated balance sheet as total consolidated assets.

The following table presents certain significant segment expenses that are regularly provided to the CODM (in thousands):


	Three Months Ended March 31,
	2026			2025
Research and development expenses:
GlyphAllo direct research and development expenses	$	8,297		$	3,309
GlyphAgo direct research and development expenses		6,494			1,960
Glyph2BLSD direct research and development expenses		582			896
Preclinical and early discovery assets		944			821
Personnel-related (including stock-based compensation expense of $0.9 million and $0.5 million for three months ended March 31, 2026 and 2025, respectively)		4,600			3,156
Other indirect research and development expenses		514			392
Total research and development expenses		21,431			10,534
General and administrative expenses:
Personnel-related (including stock-based compensation expense of $1.7 million and $1.1 million for three months ended March 31, 2026 and 2025, respectively)		4,124			3,024
Other general and administrative expenses(1)		1,988			2,627
Total general and administrative expenses		6,112			5,651
Other segment items(2)		(2,135	)		(3,060	)
Net loss	$	25,408		$	13,125

(1)

Other general and administrative expenses include professional fees, facilities, depreciation, IT, and other expenses.

(2)

Other segment items include interest income, net, research and development tax credit, income tax provision, and other expense, net.

16. Net Loss per Share

Under the two-class method, basic net loss per share is calculated by dividing the net loss attributable to common stockholders by the weighted average number of shares of common stock outstanding during the period, without consideration for potentially dilutive securities. The net loss available to common stockholders was not allocated to the Preferred Stock as the holders did not have a contractual obligation to share in losses. Diluted net loss per share is the same as basic net loss per share for the three months ended March 31, 2026 and 2025, presented since the effects of any potentially dilutive securities, would be antidilutive given the net loss of the Company.

Basic and diluted net loss per share is calculated as follows (in thousands except share and per share amounts):


	Three Months Ended March 31,
	2026			2025
Net loss	$	(25,408	)	$	(13,125	)
Net loss per share, basic and diluted	$	(10.34	)	$	(5.65	)
Weighted-average shares outstanding, basic and diluted		2,456,766			2,323,724

For accounting purposes, the computation of basic and diluted weighted-average common shares outstanding for the three months ended March 31, 2026 and 2025, excludes all shares of unvested restricted common stock as such shares are not considered outstanding. See Note 11—Stock-Based Compensation, for more information.

The following outstanding potentially dilutive securities have been excluded from the calculation of diluted net loss per share attributable to common stockholders, as their effect is antidilutive:


	Three Months Ended March 31,
	2026		2025
Stock options to purchase common stock (1)		9,319,500		8,304,263
Unvested restricted stock awards		121,612		254,278
Series A-1 Preferred Stock (as converted to common stock)		12,736,014		12,736,014
Series A-2 Preferred Stock (as converted to common stock)		8,387,331		8,387,331
Series B Preferred Stock (as converted to common stock)		15,149,130		15,149,130
Total		36,272,475		36,272,475

(1)

The table above excludes the performance-based options that have not been deemed granted from an accounting perspective. See Note 11—Stock-Based Compensation, for more information.

17. RELATED PARTIES

During the three months ended March 31, 2026, the Company incurred immaterial expenses from PureTech under the TSA related to general and administrative expenses. During the three months ended March 31, 2025, the Company incurred $0.2 million of expenses from PureTech under the TSA, primarily related to research and development expenses.

18. SUBSEQUENT EVENTS

2026 Equity Plans

In January 2026, the Board and the Company's stockholders adopted and approved the 2026 Equity Incentive Plan (the "2026 Plan"), which became effective on May 2, 2026, the date immediately preceding the date that the registration statement on Form S-1 for the Company's IPO was declared effective by the SEC. The 2026 Plan initially reserved 6,020,000 shares of common stock for future issuances and is subject to automatic increases in the number of shares of common stock reserved for future issuances in accordance with the evergreen provisions in the 2026 Plan. The shares reserved for future issuance under the 2024 Plan ceased to be available for issuance at the time the 2026 Plan became effective. Any shares underlying outstanding stock awards granted under the 2024 Plan that subsequently expire or are repurchased, forfeited, cancelled, or withheld will return to the 2026 Plan and be reserved and available for issuance. On the effective date of the registration statement, the Company granted certain executive officers and directors an aggregate of 3,172,781 options to purchase shares under the 2026 Plan with an exercise price equal to $18.00, subject to continued service through such grant date. Based on the fair value of $18.00 per share, the company estimates that the aggregate grant-date fair value of the shares that were granted in connection with the IPO is approximately $41.8 million, which is expected to be recognized as stock-based compensation expense over a period of immediate vesting to four years.

In May 2026, the Board and the Company's stockholders adopted and approved the 2026 Employee Stock Purchase Plan (the "2026 ESPP"), which became effective on May 2, 2026, the date immediately preceding the date that the registration statement on Form S-1 for the Company's IPO was declared effective by the SEC. The 2026 ESPP initially reserved 510,000 shares of common stock for future issuance and is subject to automatic increases in the number of shares of common stock reserved for future issuances in accordance with the evergreen provisions in the 2026 ESPP.

Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations.

You should read the following discussion and analysis of our financial condition and results of operations in conjunction with our condensed consolidated financial statements and related notes appearing elsewhere in this Quarterly Report and our audited consolidated financial statements and related notes included in our final prospectus for our initial public offering ("IPO") filed with the SEC pursuant to Rule 424(b)(4) under the Securities Act of 1933, as amended (the “Securities Act”) on May 1, 2026 (the “IPO Prospectus”). References to the "Company," “Seaport,” "Seaport Therapeutics," “we,” “our,” “us,” or similar terms refer to Seaport Therapeutics, Inc. and its wholly owned subsidiaries, or either or all of them as the context may require. This discussion and analysis and other parts of this Quarterly Report on Form 10-Q contain forward-looking statements based upon our current plans and expectations that involve risks, uncertainties and assumptions, such as statements regarding our plans, strategies, objectives, expectations, intentions, and beliefs. Our actual results and the timing of events could differ materially from those anticipated in these forward-looking statements as a result of various factors, including those set forth under “Risk Factors” and elsewhere in this Quarterly Report on Form 10-Q. You should carefully read the sections entitled “Risk Factors” and “Special Note Regarding Forward-Looking Statements” to gain an understanding of the important factors that could cause actual results to differ materially from our forward-looking statements.

Overview

We are a clinical-stage therapeutics company focused on inventing and developing new medicines for patients with depression, anxiety, and other debilitating neuropsychiatric disorders. Through our differentiated approach, we identify clinically validated mechanisms with established efficacy and safety profiles which had historically been limited by high first-pass metabolism, low bioavailability, and/or side effects. We apply our proprietary Glyph platform to overcome those limitations and invent innovative oral therapies.

Our lead product candidate, GlyphAllo ("Glyph Allopregnanolone"), is a novel, Glyphed oral prodrug of allopregnanolone, an endogenous molecule that has been clinically validated in two third-party trials in the United States for the treatment of postpartum depression, or PPD, a form of major depressive disorder, or MDD, as a rapidly acting antidepressant with anxiolytic and sleep-promoting effects. We have initiated the Phase 2b BUOY-1 trial in patients with MDD with or without anxious distress and anticipate topline data in the first half of 2027. Given the strength in enrollment and to maximize the likelihood that the BUOY-1 trial could be used to support registration, we plan to enroll the full prespecified target sample size of approximately 360 patients and no longer intend to perform a sample size re-estimation (SSRE). We have dosed the first patient in a Phase 1 driving simulation trial of GlyphAllo, with topline data expected in the second half of 2026, in advance of the expected topline readout of the BUOY-1 trial.

Our second product candidate, GlyphAgo ("Glyph Agomelatine"), is a novel, Glyphed oral prodrug of agomelatine, a clinically validated anxiolytic and antidepressant that is approved for the treatment of generalized anxiety disorder, or GAD, in Australia and MDD in Australia and the European Union, or EU. In April 2026, we reported topline data from the single-ascending dose, or SAD, and crossover portions of our Phase 1 proof-of-concept clinical trial for GlyphAgo. In the head-to-head crossover portion of the trial, GlyphAgo demonstrated a 6.8-fold increase in bioavailability of agomelatine compared to unmodified orally administered agomelatine, and showed significantly lower (10-fold) pharmacokinetic variability compared to unmodified agomelatine. In the SAD portion of the trial, GlyphAgo demonstrated a 9.6 to 14.5-fold increase in dose-normalized exposure compared to agomelatine. GlyphAgo was well-tolerated and no liver-related adverse events were observed. In June 2026, we reported topline data from the multiple-ascending dose, or MAD, portion of the trial, which showed that seven-day dosing of GlyphAgo achieved therapeutic exposures of agomelatine at doses projected to avoid liver enzyme elevations and reduce or eliminate the need for liver function testing, and demonstrated favorable safety and tolerability, with no liver-related adverse events observed. We plan to initiate a Phase 2a proof-of-pharmacology trial designed to evaluate the potential sleep benefit of GlyphAgo in patients with GAD and sleep disturbance, with topline data expected in early 2028 and, in parallel, a Phase 2b trial designed to evaluate the efficacy and safety of GlyphAgo in patients with GAD, with topline data expected by the end of 2028.

We are also advancing Glyph2BLSD (Glyph 2-bromo-LSD), a novel, Glyphed oral prodrug of the non-hallucinogenic LSD analog 2-bromo-LSD, in preclinical studies for depressive disorders, including treatment-resistant depression, or TRD, post-traumatic stress disorder, or PTSD, and headache disorders.

We have devoted substantially all of our efforts to organizing and staffing our company, business planning, capital raising, research and development activities, building and strengthening our intellectual property portfolio, and providing general and administrative support for these operations. We have funded our operations with proceeds from the issuance and sale of convertible preferred stock, including the $100.1 million gross proceeds we received in April 2024 from our Series A-2 Financing and the $226.0 million gross proceeds we received in October 2024 from our Series B Financing. During the second quarter of 2026, we completed our IPO, in which we sold an aggregate 14,446,658 shares of our common stock, including 286,568 shares issued pursuant to the exercise of the underwriters' overallotment option, at a public offering price of $18.00 per share resulting in aggregate net proceeds of approximately $238.7 million, after deducting underwriter discounts, commissions and other estimated offering expenses.

We have incurred significant operating losses since the inception of our business and expect to continue to generate operating losses for the foreseeable future, and expect that our expenses and operating losses will continue to increase substantially. Our ability to generate product revenue sufficient to achieve profitability will depend on the successful development and eventual commercialization of any product candidates we may develop. During the three months ended March 31, 2026 and 2025, we had a net loss of $25.4 million and $13.1 million, respectively. As of March 31, 2026, we had an accumulated deficit of $139.5 million. Our net losses may fluctuate significantly from quarter-to-quarter and year-to-year, depending on the timing of our preclinical studies and planned clinical trials and our expenditures on other research and development activities.

We do not expect to generate any revenue from product sales unless and until we successfully complete development and obtain regulatory approval for one or more of our potential future product candidates, which may not be for at least the next several years, if ever. If we obtain regulatory approval for any of our existing or future product candidates, we expect to incur significant commercialization expenses related to product sales, marketing, manufacturing, and distribution. Accordingly, until such time as we can generate significant revenue from our existing or future product candidates, if ever, we expect to finance our cash needs through equity offerings, debt financings, or other capital sources, including potential collaborations, licenses, and other similar arrangements. See the section titled “Liquidity and Capital Resources.” However, we may be unable to raise additional funds or enter into such other arrangements when needed on favorable terms or at all. Our inability to raise capital or enter into such other arrangements when needed would have a negative impact on our financial condition and could force us to delay, limit, reduce, or terminate our product development or future commercialization efforts or grant rights to develop and market potential future product candidates that we would otherwise prefer to develop and market ourselves.

As of March 31, 2026, we had cash, cash equivalents and investments of $212.6 million. Based on our current operating plans, we believe that our existing cash, cash equivalents and investments, together with the net proceeds from our IPO completed during the second quarter of 2026, will be sufficient to fund our operating expenses and capital expenditure requirements into 2029.

Components of Results of Operations

Revenue

To date, we have not recognized any revenue and do not expect to generate any revenue from the sale of products in the near term, if at all. If our development efforts for our current or potential future product candidates are successful and result in regulatory approval or if we enter into additional license or collaboration agreements with third parties, we may generate revenue in the future from product sales, payments from such license or collaboration agreements, or any combination thereof. However, there can be no assurance as to when we will generate such revenue, if at all.

Operating Expenses

Research and Development Expenses

Research and development, or R&D, expenses consist primarily of costs incurred in connection with the discovery, non-clinical development, and clinical development of our lead product candidates and potential future product candidates. R&D expenses include direct costs specifically attributable to our programs including external fees to conduct certain clinical and non-clinical research and development activities, preclinical and early discovery assets, such as costs paid to contract research and manufacturing organizations, consulting fees, laboratory services and supplies, and costs incurred in connection with the Monash License Agreement, as well as indirect costs that are not directly attributable to a specific program such as personnel related expenses, including stock-based compensation, facility expenses, depreciation, and information technology costs.

We expense research and development costs as incurred. We recognize direct development costs based on an evaluation of the progress to completion of specific tasks using information provided to us by our vendors or our estimate of the level of service that has been performed at each reporting date. Payments for these activities are based on the terms of the individual agreements, which may differ from the pattern of costs incurred, and are reflected in our condensed consolidated financial statements as prepaid or accrued research and development expenses.

Due to the inherently unpredictable nature of preclinical and clinical development, we do not allocate all of our internal research and development expenses on a program-by-program basis as these expenses primarily relate to personnel and other overhead costs that are deployed across multiple programs under development. Our research and development expenses also include external costs, which we do track on a program-by-program basis following the program’s nomination as a product candidate. We began tracking such external costs upon the nomination for GlyphAllo in 2020, GlyphAgo in 2023 and Glyph2BLSD in 2024.

Research and development activities are central to our business model. We expect that our research and development expenses will continue to increase for the foreseeable future as we advance our current and any future product candidates into and through clinical development and as we continue to develop additional product candidates.

General and Administrative Expenses

General and administrative expenses consist of salaries and personnel-related costs, including stock-based compensation expense, for our personnel in executive, business development, legal, finance and accounting, human resources and other administrative functions, consulting fees, facility costs not otherwise included in R&D expenses, fees paid for accounting and tax services, insurance expenses, legal costs consisting of general corporate legal fees and patent legal fees.

We anticipate that our general and administrative expenses will increase in the future as we increase our headcount to support the expansion of our business, particularly in support of development of product candidates and our continued research and clinical development activities. We will also incur significant costs associated with being a public company, including increased accounting, audit, legal, regulatory, compliance, and director and officer insurance costs, as well as expenses related to services associated with maintaining compliance with the requirements of the Nasdaq Stock Market, the Securities and Exchange Commission, and investor relations costs.

Other Income (Expense), Net

Other income (expense), net consists primarily of interest income earned on our investments and cash equivalents, research and development tax credits from the Australian government’s tax incentive program, and realized and unrealized foreign currency gains and losses.

Provision for Income Taxes

Provision for income taxes consists of United States federal and state income taxes in jurisdictions in which we conduct business and foreign income taxes related to our Australian subsidiary. The provision for income taxes is based on our taxable income. Our loss before income taxes is adjusted for permanent and temporary tax differences, primarily related to capitalized non-U.S. research and development expenses, resulting in taxable income or loss. We recorded a full valuation allowance of our U.S. deferred tax asset position as of March 31, 2026 and 2025 as we believe it was more likely than not that we would not be able to utilize our deferred tax assets.

Results of Operations

Comparison of the three months ended March 31, 2026 and 2025

The following table summarizes our results of operations (in thousands):


	Three Months Ended March 31,
	2026			2025			$ Change
Operating expenses:
Research and development (including stock-based compensation expense of $0.9 million and $0.5 million for the three months ended March 31, 2026 and 2025, respectively)	$	21,431		$	10,534		$	10,897
General and administrative (including stock-based compensation expense of $1.7 million and $1.1 million for the three months ended March 31, 2026 and 2025, respectively)		6,112			5,651			461
Total operating expenses		27,543			16,185			11,358
Loss from operations		(27,543	)		(16,185	)	$	(11,358	)
Other income (expense), net		2,133			3,100		$	(967	)
Other income, net		521			(9	)	$	530
Total other income, net		2,654			3,091			(437	)
Loss before income taxes		(24,889	)		(13,094	)	$	(11,795	)
Income tax provision		519			31		$	488
Net loss	$	(25,408	)	$	(13,125	)	$	(12,283	)

Research and Development Expenses

The following table summarizes our research and development expenses (in thousands):


	Three Months Ended March 31,
	2026		2025		$ Change
Direct costs:
GlyphAllo	$	8,297	$	3,309	$	4,988
GlyphAgo		6,494		1,960		4,534
Glyph2BLSD		582		896		(314	)
Preclinical and early discovery assets		944		821		123
Indirect costs:
Employee compensation (excluding stock-based compensation)		3,709		2,659		1,050
Stock-based compensation		891		497		394
Other research and development		514		392		122
Total research and development expenses	$	21,431	$	10,534	$	10,897

Research and development expenses increased by $10.9 million from $10.5 million for the three months ended March 31, 2025 to $21.4 million for the three months ended March 31, 2026. The increase in research and development expenses was primarily attributable to:

•

$5.0 million of increased costs associated with our lead program GlyphAllo, which was primarily due to advancement of our Phase 2b BUOY-1 trial which commenced in July 2025;

•

$4.5 million of increased costs associated with our GlyphAgo program, which was primarily due to advancement of our Phase 1 trial, for which we announced dosing of the first participant in September 2025 and completed the study in the second quarter of 2026;

•

$1.1 million of increased costs associated with employee compensation primarily due to increased headcount to support our research and development operations; and

•

$0.4 million of increased costs associated with stock-based compensation costs primarily due to additional equity grants issued under our 2024 Equity Plan, partially offset by;

•

$0.3 million of decreased costs associated with our Glyph2BLSD program due to timing of our research activities.

General and Administrative Expenses

The following table summarizes our general and administrative expenses (in thousands):


	Three Months Ended March 31,
	2026		2025		$ Change
Employee compensation (excluding stock-based compensation)	$	2,446	$	1,902	$	544
Stock-based compensation		1,678		1,122		556
Professional fees		1,201		1,883		(682	)
Facilities, depreciation, IT, and other		787		744		43
Total general and administrative expenses	$	6,112	$

Seaport Therapeutics, Inc. 10-Q