Related Parties (Additional Information) (Details) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended			3 Months Ended						9 Months Ended
	Jan. 31, 2026	Apr. 30, 2026	Jan. 31, 2026	Mar. 31, 2025	Sep. 30, 2026	Jun. 30, 2026	Mar. 31, 2026	Sep. 30, 2025	Jun. 30, 2025	Mar. 31, 2025	Sep. 30, 2026	Sep. 30, 2025	Aug. 31, 2026	Dec. 31, 2025	Dec. 31, 2024
Related Party Transaction [Line Items]
Purchase price					$ 149	$ 14	$ 6	$ 1	$ 6	$ 4
Fixed lease payments		$ 3,300
Series B Redeemable Convertible Preferred Stock [Member]
Related Party Transaction [Line Items]
Redeemable convertible preferred stock outstanding				27,206,115	43,388,910	43,388,910	43,388,910	27,206,115	27,206,115	27,206,115	43,388,910	27,206,115		27,206,115	13,683,972
Temporary equity, shares issued					43,388,910						43,388,910			27,206,115
Issuance of Preferred Stock, Value							$ 49,823			$ 41,769
Temporary equity stock issued during period shares new issues			16,182,795	13,522,143
Series A-2 Redeemable Convertible Preferred Stock [Member]
Related Party Transaction [Line Items]
Redeemable convertible preferred stock outstanding				7,700,000	7,700,000	7,700,000	7,700,000	7,700,000	7,700,000	7,700,000	7,700,000	7,700,000		7,700,000	7,700,000
Temporary equity, shares issued					7,700,000						7,700,000			7,700,000
Series A-3 Redeemable Convertible Preferred Stock [Member]
Related Party Transaction [Line Items]
Redeemable convertible preferred stock outstanding				12,482,976	12,482,976	12,482,976	12,482,976	12,482,976	12,482,976	12,482,976	12,482,976	12,482,976		12,482,976	12,482,976
Temporary equity, shares issued					12,482,976						12,482,976			12,482,976
Lilly [Member]
Related Party Transaction [Line Items]
Related party percentage of outstanding capital stock					10.00%						10.00%			10.00%
Services agreement expenses					$ 200			$ 0			$ 200	$ 0
Lilly [Member] | Series B Redeemable Convertible Preferred Stock [Member]
Related Party Transaction [Line Items]
Redeemable convertible preferred stock outstanding					8,098,748						8,098,748			5,860,808
Temporary equity, shares issued				2,930,404						2,930,404
Shares issued, price per share				$ 3.0897			$ 3.0897			$ 3.0897
Issuance of Preferred Stock, Value	$ 6,900			$ 9,100
Temporary equity stock issued during period shares new issues	2,237,940		2,237,940
Lilly [Member] | Series A-2 Redeemable Convertible Preferred Stock [Member]
Related Party Transaction [Line Items]
Redeemable convertible preferred stock outstanding					7,700,000						7,700,000			7,700,000
Lilly [Member] | Series A-3 Redeemable Convertible Preferred Stock [Member]
Related Party Transaction [Line Items]
Redeemable convertible preferred stock outstanding					2,002,487						2,002,487			2,002,487
Johnson & Johnson Innovation [Member] | Series B Redeemable Convertible Preferred Stock [Member]
Related Party Transaction [Line Items]
Redeemable convertible preferred stock outstanding					2,217,311						2,217,311			1,604,598
Temporary equity, shares issued				802,299						802,299
Shares issued, price per share	$ 3.0897		$ 3.0897	$ 3.0897						$ 3.0897
Temporary equity stock issued during period shares new issues	612,713		612,713
Proceeds from Issuance of Convertible Preferred Stock			$ 1,900	$ 2,500
Johnson & Johnson Innovation [Member] | Series A-3 Redeemable Convertible Preferred Stock [Member]
Related Party Transaction [Line Items]
Redeemable convertible preferred stock outstanding					2,656,391						2,656,391			2,656,391
Johnson & Johnson Innovation [Member] | Minimum [Member]
Related Party Transaction [Line Items]
Related party percentage of outstanding capital stock					5.00%						5.00%			5.00%
Alexandria Real Estate Equities, Inc [Member]
Related Party Transaction [Line Items]
Related party percentage of outstanding capital stock					5.00%						5.00%			5.00%
Alexandria Real Estate Equities, Inc [Member] | Series B Redeemable Convertible Preferred Stock [Member]
Related Party Transaction [Line Items]
Redeemable convertible preferred stock outstanding					3,480,387						3,480,387			2,912,904
Shares issued, price per share	$ 3.0897		$ 3.0897	$ 3.0897						$ 3.0897
Temporary equity stock issued during period shares new issues			567,483	1,456,452
Proceeds from Issuance of Convertible Preferred Stock			$ 1,800	$ 4,500
Alexandria Real Estate Equities, Inc [Member] | Series A-3 Redeemable Convertible Preferred Stock [Member]
Related Party Transaction [Line Items]
Redeemable convertible preferred stock outstanding					1,033,541						1,033,541			1,033,541
ARE-San Francisco No. 46, LLC [Member]
Related Party Transaction [Line Items]
Prepaid rent					$ 200						$ 200
Initial term of lease contract													27 months
Initial term of lease contract expire											Nov. 30, 2028
Fixed lease payments		$ 3,300
Lease expense					$ 200						$ 200