v3.25.4

Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Operating Loss Carryforwards [Line Items]
Provision for income taxes	$ 0	$ 0
Research and development credits	14,491,000	13,554,000
Gross unrecognized tax benefits	3,675,000	3,452,000	$ 3,010,000
Unrecognized tax benefits that would affect effective tax rate	0
Interest or penalties related income tax	0	0
Accrual for interest or penalties related to income tax	0	0
Federal
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards which are carried over indefinitely	1,000,000,000	$ 863,200,000
Research and development credits	$ 17,200,000
Research and development credits expiration period	2038
State
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 387,100,000
Net operating loss carryforwards expiration year	2033
Research and development credits	$ 1,200,000
Research and development credits expiration period	2026

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Phathom Pharmaceuticals, Inc. 10-K