v3.25.2

Segment Reporting - Schedule of Segment Net Loss, Including Disaggregated Components of Operating Expenses (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2025	Mar. 31, 2025	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2025	Jun. 30, 2024
Segment Reporting Information [Line Items]
Collaboration revenue	$ 937		$ 510		$ 1,503	$ 1,150
Research and development:
Manufacturing costs	10,000		1,416		12,129	1,641
Personnel expenses	4,509		2,404		8,214	4,839
Professional fees and other	1,079		1,242		2,571	2,542
Total research and development expenses	37,865		14,069		63,662	25,760
General and administrative:
Personnel expenses	3,773		2,313		8,005	4,689
Professional fees	2,397		1,334		3,893	2,461
Other	1,249		334		2,303	793
Total general and administrative expenses	7,419		3,981		14,201	7,943
Total operating expenses	45,284		18,050		77,863	33,703
Loss from operations	(44,347)		(17,540)		(76,360)	(32,553)
Other income (expense):
Change in fair value of preferred stock tranche right liabilities	0		0		0	2,859
Interest income	4,431		2,877		9,174	4,143
Other expense, net	(50)		(15)		(50)	(21)
Total other income, net	4,381		2,862		9,124	6,981
Net loss	(39,966)	$ (27,270)	(14,678)	$ (10,894)	(67,236)	(25,572)
Asthma Indication
Research and development:
Verekitug program	13,236		6,935		23,257	13,102
CRSwNP Indication
Research and development:
Verekitug program	2,238		$ 2,072		5,001	$ 3,636
COPD Indication
Research and development:
Verekitug program	$ 6,803				$ 12,490

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Upstream Bio, Inc. 10-Q