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Fairmount, Mr. Harwin, and Mr. Kiselak disclaim beneficial ownership of any of the reported securities, except to the extent of their pecuniary interest therein."}],"balance_after":2359025,"source":{"system":"sec-edgar","filing":"0001104659-26-038546","document":"tm2610877-1_4seq1.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1663607/000110465926038546/tm2610877-1_4seq1.xml","form_type":"4"}},{"id":823997,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":36288,"kind":"person","name":"MOULDER LEON O JR","position":1,"cik":"0001228865","reported_name":"MOULDER LEON O JR","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Executive Officer"}}],"security":"Common Stock","published_at":"2026-04-01T00:14:23.000Z","date":"2026-03-31","kind":"purchase","planned":false,"acquired":true,"shares":34000,"price":19.31,"value":656540.0,"ownership":{"direct":false,"nature":"See Footnote"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F3","text":"The price reported is a weighted average price. These shares were purchased in multiple transactions ranging from $18.84 to $19.58, inclusive. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Leon O. Moulder, Jr. is the Managing Member of Tellus BioVentures LLC (\"Tellus\") and may be deemed to have sole voting and dispositive power over the shares held by Tellus. Mr. Moulder is the Issuer's chief executive officer and Chairman of its board of directors. Mr. Moulder disclaims beneficial ownership of such securities except to the extent of his pecuniary interest therein."}],"balance_after":1726039,"source":{"system":"sec-edgar","filing":"0001104659-26-038031","document":"tm2610818-1_4seq1.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1228865/000110465926038031/tm2610818-1_4seq1.xml","form_type":"4"}},{"id":823996,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":36288,"kind":"person","name":"MOULDER LEON O JR","position":1,"cik":"0001228865","reported_name":"MOULDER LEON O JR","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Executive Officer"}}],"security":"Common Stock","published_at":"2026-04-01T00:14:23.000Z","date":"2026-03-30","kind":"purchase","planned":false,"acquired":true,"shares":20000,"price":18.23,"value":364600.0,"ownership":{"direct":false,"nature":"See Footnote"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The price reported is a weighted average price. These shares were purchased in multiple transactions ranging from $18.195 to $18.25, inclusive. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Leon O. Moulder, Jr. is the Managing Member of Tellus BioVentures LLC (\"Tellus\") and may be deemed to have sole voting and dispositive power over the shares held by Tellus. Mr. Moulder is the Issuer's chief executive officer and Chairman of its board of directors. Mr. Moulder disclaims beneficial ownership of such securities except to the extent of his pecuniary interest therein."}],"balance_after":1692039,"source":{"system":"sec-edgar","filing":"0001104659-26-038031","document":"tm2610818-1_4seq1.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1228865/000110465926038031/tm2610818-1_4seq1.xml","form_type":"4"}},{"id":823887,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":37101,"kind":"person","name":"Lu Hongbo","position":1,"cik":"0001767584","reported_name":"Lu Hongbo","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common Stock","published_at":"2026-03-31T21:00:23.000Z","date":"2026-03-31","kind":"purchase","planned":false,"acquired":true,"shares":75000,"price":20,"value":1500000.0,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"Acquired in an underwritten public offering, pursuant to which Zenas BioPharma, Inc. sold shares of common stock at a purchase price of $20.00 per share."},{"field":"ownership.direct","element":"directOrIndirectOwnership","label":"F2","text":"The reported securities are owned directly by NEXTBio Master Fund LP or NEXTBio Evergreen LLC and may be deemed to be indirectly beneficially owned by (i) NEXTBio Capital LLC, the general partner of NEXTBio Master Fund LP (with respect to such securities directly owned by NEXTBio Master Fund LP), (ii) NEXTBio Capital Evergreen GP LLC, the managing member of NEXTBio Evergreen LLC (with respect to such securities directly owned by NEXTBio Evergreen LLC), (iii) NEXTBio Capital Management LP, the investment manager to NEXTBio Master Fund LP and NEXTBio Evergreen LLC, and (iv) Hongbo Lu, a managing member of NEXTBio Capital LLC and NEXTBio Capital Evergreen GP LLC."},{"field":"ownership.direct","element":"directOrIndirectOwnership","label":"F3","text":"The Reporting Person disclaims beneficial ownership of the reported securities except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of the securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"The reported securities are owned directly by NEXTBio Master Fund LP or NEXTBio Evergreen LLC and may be deemed to be indirectly beneficially owned by (i) NEXTBio Capital LLC, the general partner of NEXTBio Master Fund LP (with respect to such securities directly owned by NEXTBio Master Fund LP), (ii) NEXTBio Capital Evergreen GP LLC, the managing member of NEXTBio Evergreen LLC (with respect to such securities directly owned by NEXTBio Evergreen LLC), (iii) NEXTBio Capital Management LP, the investment manager to NEXTBio Master Fund LP and NEXTBio Evergreen LLC, and (iv) Hongbo Lu, a managing member of NEXTBio Capital LLC and NEXTBio Capital Evergreen GP LLC."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"The Reporting Person disclaims beneficial ownership of the reported securities except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of the securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose."}],"balance_after":422968,"source":{"system":"sec-edgar","filing":"0001104659-26-037865","document":"tm2610681-1_4seq1.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1767584/000110465926037865/tm2610681-1_4seq1.xml","form_type":"4"}},{"id":904565,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":37101,"kind":"person","name":"Lu Hongbo","position":1,"cik":"0001767584","reported_name":"Lu Hongbo","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common Stock","published_at":"2026-02-13T22:35:50.000Z","date":"2026-02-11","kind":"purchase","planned":false,"acquired":true,"shares":25985,"price":22.5,"value":584662.5,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"ownership.direct","element":"directOrIndirectOwnership","label":"F1","text":"The reported securities are owned directly by NEXTBio Master Fund LP or NEXTBio Evergreen LLC and may be deemed to be indirectly beneficially owned by (i) NEXTBio Capital LLC, the general partner of NEXTBio Master Fund LP (with respect to such securities directly owned by NEXTBio Master Fund LP), (ii) NEXTBio Capital Evergreen GP LLC, the managing member of NEXTBio Evergreen LLC (with respect to such securities directly owned by NEXTBio Evergreen LLC), (iii) NEXTBio Capital Management LP, the investment manager to NEXTBio Master Fund LP and NEXTBio EverGreen LLC, and (iv) Hongbo Lu, a managing member of NEXTBio Capital LLC and NEXTBio Capital Evergreen GP LLC."},{"field":"ownership.direct","element":"directOrIndirectOwnership","label":"F2","text":"The Reporting Person disclaims beneficial ownership of the reported securities except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of the securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F1","text":"The reported securities are owned directly by NEXTBio Master Fund LP or NEXTBio Evergreen LLC and may be deemed to be indirectly beneficially owned by (i) NEXTBio Capital LLC, the general partner of NEXTBio Master Fund LP (with respect to such securities directly owned by NEXTBio Master Fund LP), (ii) NEXTBio Capital Evergreen GP LLC, the managing member of NEXTBio Evergreen LLC (with respect to such securities directly owned by NEXTBio Evergreen LLC), (iii) NEXTBio Capital Management LP, the investment manager to NEXTBio Master Fund LP and NEXTBio EverGreen LLC, and (iv) Hongbo Lu, a managing member of NEXTBio Capital LLC and NEXTBio Capital Evergreen GP LLC."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"The Reporting Person disclaims beneficial ownership of the reported securities except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of the securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose."}],"balance_after":347968,"source":{"system":"sec-edgar","filing":"0001104659-26-015387","document":"tm266411-2_4seq1.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1767584/000110465926015387/tm266411-2_4seq1.xml","form_type":"4"}},{"id":904845,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":37171,"kind":"person","name":"Allen Patricia L","position":1,"cik":"0001348587","reported_name":"Allen Patricia L","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common 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Stock","published_at":"2026-02-13T22:06:22.000Z","date":"2026-02-12","kind":"purchase","planned":false,"acquired":true,"shares":5000,"price":26.5,"value":132500.0,"ownership":{"direct":true},"balance_after":15700,"source":{"system":"sec-edgar","filing":"0001104659-26-015342","document":"tm266411-1_4seq1.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1348587/000110465926015342/tm266411-1_4seq1.xml","form_type":"4"}},{"id":904843,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":37171,"kind":"person","name":"Allen Patricia L","position":1,"cik":"0001348587","reported_name":"Allen Patricia L","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common 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These shares were purchased in multiple transactions ranging from $24.12 to $24.7, inclusive. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range."}],"balance_after":10700,"source":{"system":"sec-edgar","filing":"0001104659-26-015342","document":"tm266411-1_4seq1.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1348587/000110465926015342/tm266411-1_4seq1.xml","form_type":"4"}},{"id":904842,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":37171,"kind":"person","name":"Allen Patricia L","position":1,"cik":"0001348587","reported_name":"Allen Patricia L","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common Stock","published_at":"2026-02-13T22:06:22.000Z","date":"2026-02-12","kind":"purchase","planned":false,"acquired":true,"shares":5000,"price":23.77,"value":118850.0,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The price reported is a weighted average price. These shares were purchased in multiple transactions ranging from $23.38 to $24.07, inclusive. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range."}],"balance_after":5000,"source":{"system":"sec-edgar","filing":"0001104659-26-015342","document":"tm266411-1_4seq1.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1348587/000110465926015342/tm266411-1_4seq1.xml","form_type":"4"}},{"id":921410,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":36288,"kind":"person","name":"MOULDER LEON O JR","position":1,"cik":"0001228865","reported_name":"MOULDER LEON O JR","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Executive Officer"}}],"security":"Common Stock","published_at":"2026-02-03T21:30:13.000Z","date":"2026-02-02","kind":"purchase","planned":false,"acquired":true,"shares":57000,"price":17.96,"value":1023720.0,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The price reported is a weighted average price. These shares were purchased in multiple transactions ranging from $17.69 to $18.14, inclusive. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range."}],"balance_after":423155,"source":{"system":"sec-edgar","filing":"0001104659-26-009756","document":"tm264991-1_4seq1.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1228865/000110465926009756/tm264991-1_4seq1.xml","form_type":"4"}},{"id":941933,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":36288,"kind":"person","name":"MOULDER LEON O JR","position":1,"cik":"0001228865","reported_name":"MOULDER LEON O JR","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Executive Officer"}}],"security":"Common Stock","published_at":"2026-01-10T02:42:58.000Z","date":"2026-01-09","kind":"purchase","planned":false,"acquired":true,"shares":20000,"price":16.55,"value":331000.0,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F3","text":"The price reported is a weighted average price. These shares were purchased in multiple transactions ranging from $16.05 to $16.87, inclusive. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range."}],"balance_after":366155,"source":{"system":"sec-edgar","filing":"0001104659-26-002589","document":"tm262858-1_4seq1.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1228865/000110465926002589/tm262858-1_4seq1.xml","form_type":"4"}},{"id":941932,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":36288,"kind":"person","name":"MOULDER LEON O JR","position":1,"cik":"0001228865","reported_name":"MOULDER LEON O JR","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Executive Officer"}}],"security":"Common Stock","published_at":"2026-01-10T02:42:58.000Z","date":"2026-01-08","kind":"purchase","planned":false,"acquired":true,"shares":30000,"price":16.3,"value":489000.0,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported is a weighted average price. These shares were purchased in multiple transactions ranging from $15.82 to $16.60, inclusive. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range."}],"balance_after":346155,"source":{"system":"sec-edgar","filing":"0001104659-26-002589","document":"tm262858-1_4seq1.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1228865/000110465926002589/tm262858-1_4seq1.xml","form_type":"4"}},{"id":941931,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":36288,"kind":"person","name":"MOULDER LEON O JR","position":1,"cik":"0001228865","reported_name":"MOULDER LEON O JR","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Executive Officer"}}],"security":"Common Stock","published_at":"2026-01-10T02:42:58.000Z","date":"2026-01-07","kind":"purchase","planned":false,"acquired":true,"shares":50000,"price":16.38,"value":819000.0,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The price reported is a weighted average price. These shares were purchased in multiple transactions ranging from $16.21 to $16.53, inclusive. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range."}],"balance_after":316155,"source":{"system":"sec-edgar","filing":"0001104659-26-002589","document":"tm262858-1_4seq1.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1228865/000110465926002589/tm262858-1_4seq1.xml","form_type":"4"}},{"id":1019200,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":10038,"kind":"person","name":"Nunn Jason Raleigh","position":1,"cik":"0001444319","reported_name":"Nunn Jason Raleigh","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common Stock","published_at":"2025-10-14T21:16:29.000Z","date":"2025-10-09","kind":"purchase","planned":false,"acquired":true,"shares":63158,"price":19,"value":1200002.0,"ownership":{"direct":false,"nature":"See Note 2"},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"Acquired from the Issuer on October 9, 2025 pursuant to a Securities Purchase Agreement dated October 7, 2025."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"The reported securities are held directly by SR One Capital Opportunities Fund I, LP. SR One Capital Opportunities Partners I, LP is the general partner of SR One Capital Opportunities Fund I, LP. The Reporting Person is a partner of SR One Capital Management, LP, an entity affiliated with SR One Capital Opportunities Fund I, LP, and a limited partner of SR One Capital Opportunities Partners I, LP. The Reporting Person disclaims beneficial ownership of these securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended (\"Section 16\"), except to the extent of his pecuniary interest therein, if any, and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of such securities for Section 16 or any other purpose."}],"balance_after":1173395,"source":{"system":"sec-edgar","filing":"0001193125-25-239158","document":"ownership.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1444319/000119312525239158/ownership.xml","form_type":"4"}},{"id":1019347,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":48340,"kind":"organization","name":"SR ONE CAPITAL MANAGEMENT, LLC","position":1,"cik":"0001853723","reported_name":"SR ONE CAPITAL MANAGEMENT, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":39164,"kind":"person","name":"George Simeon","position":2,"cik":"0001595117","reported_name":"George Simeon","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Common Stock","published_at":"2025-10-14T21:14:56.000Z","date":"2025-10-09","kind":"purchase","planned":false,"acquired":true,"shares":63157,"price":19,"value":1199983.0,"ownership":{"direct":false,"nature":"See Note 3"},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"Acquired from the Issuer on October 9, 2025 pursuant to a Securities Purchase Agreement dated October 7, 2025."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"The reported securities are held directly by AMZL, LP. SR One Capital SMA Partners, LP is the general partner of AMZL, LP, and SR One Capital Management, LLC is the general partner of SR One Capital SMA Partners, LP. Simeon George, M.D. is the managing member of SR One Capital Management, LLC. Each of SR One Capital SMA Partners, LP, SR One Capital Management, LLC and Dr. George may be deemed to have shared power to vote or dispose of these shares, and each disclaims beneficial ownership of the shares except to the extent of any pecuniary interest therein."}],"balance_after":1917895,"source":{"system":"sec-edgar","filing":"0001193125-25-239153","document":"ownership.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1853723/000119312525239153/ownership.xml","form_type":"4"}},{"id":1019346,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":48340,"kind":"organization","name":"SR ONE CAPITAL MANAGEMENT, LLC","position":1,"cik":"0001853723","reported_name":"SR ONE CAPITAL MANAGEMENT, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":39164,"kind":"person","name":"George Simeon","position":2,"cik":"0001595117","reported_name":"George Simeon","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Common Stock","published_at":"2025-10-14T21:14:56.000Z","date":"2025-10-09","kind":"purchase","planned":false,"acquired":true,"shares":63158,"price":19,"value":1200002.0,"ownership":{"direct":false,"nature":"See Note 2"},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"Acquired from the Issuer on October 9, 2025 pursuant to a Securities Purchase Agreement dated October 7, 2025."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"The reported securities are held directly by SR One Capital Opportunities Fund I, LP. SR One Capital Opportunities Partners I, LP is the general partner of SR One Capital Opportunities Fund I, LP, and SR One Capital Management, LLC is the general partner of SR One Capital Opportunities Partners I, LP. Simeon George, M.D. is the managing member of SR One Capital Management, LLC. Each of SR One Capital Opportunities Partners I, LP, SR One Capital Management, LLC and Dr. George may be deemed to have shared power to vote or dispose of these shares, and each disclaims beneficial ownership of the shares except to the extent of any pecuniary interest therein."}],"balance_after":1173395,"source":{"system":"sec-edgar","filing":"0001193125-25-239153","document":"ownership.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1853723/000119312525239153/ownership.xml","form_type":"4"}},{"id":1019085,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":847,"kind":"person","name":"ENRIGHT PATRICK G","position":1,"cik":"0001253886","reported_name":"ENRIGHT PATRICK G","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common Stock","published_at":"2025-10-14T12:59:40.000Z","date":"2025-10-09","kind":"purchase","planned":false,"acquired":true,"shares":11990,"price":20.85,"value":249991.5,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"On October 7, 2025, the Issuer entered into a Securities Purchase Agreement with certain investors, including the Reporting Person and Longitude Venture Partners IV, L.P. (\"LVPIV\")  pursuant to which the Reporting Person purchased 11,990 shares of common stock at a price per share of $20.85 and LVPIV purchased 105,265 shares of common stock as a price per share of $19.00 (the \"Offering\"). The Offering closed on October 9, 2025."}],"balance_after":11990,"source":{"system":"sec-edgar","filing":"0001193125-25-238326","document":"ownership.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1253886/000119312525238326/ownership.xml","form_type":"4"}},{"id":1019084,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":847,"kind":"person","name":"ENRIGHT PATRICK G","position":1,"cik":"0001253886","reported_name":"ENRIGHT PATRICK G","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common Stock","published_at":"2025-10-14T12:59:40.000Z","date":"2025-10-09","kind":"purchase","planned":false,"acquired":true,"shares":105265,"price":19,"value":2000035.0,"ownership":{"direct":false,"nature":"See Footnote"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"On October 7, 2025, the Issuer entered into a Securities Purchase Agreement with certain investors, including the Reporting Person and Longitude Venture Partners IV, L.P. (\"LVPIV\")  pursuant to which the Reporting Person purchased 11,990 shares of common stock at a price per share of $20.85 and LVPIV purchased 105,265 shares of common stock as a price per share of $19.00 (the \"Offering\"). The Offering closed on October 9, 2025."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Shares held by LVPIV. Longitude Capital Partners IV, LLC (\"LCPIV\") is the general partner of LVPIV and may be deemed to have voting, investment and dispositive power with respect to these securities. Juliet Tammenoms Bakker and the Reporting Person, a member of the board of directors of the Issuer, are the managing members of LCPIV and may each be deemed to share voting, investment and dispositive power with respect to these securities. Each of LCPIV, Ms. Bakker and the Reporting Person disclaims beneficial ownership of such securities except to the extent of their respective pecuniary interests therein."}],"balance_after":1832669,"source":{"system":"sec-edgar","filing":"0001193125-25-238326","document":"ownership.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1253886/000119312525238326/ownership.xml","form_type":"4"}},{"id":1020755,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":36288,"kind":"person","name":"MOULDER LEON O JR","position":1,"cik":"0001228865","reported_name":"MOULDER LEON O JR","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"See Remarks"}}],"security":"Common Stock","published_at":"2025-10-09T21:24:42.000Z","date":"2025-10-07","kind":"purchase","planned":false,"acquired":true,"shares":36928,"price":20.85,"value":769948.8,"ownership":{"direct":false,"nature":"See Footnote"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"On October 7, 2025, the Leon O. Moulder, Jr. Revocable Trust U/A dtd 9/9/2008 (the \"Trust\"), of which the reporting person is a Trustee, entered into a Securities Purchase Agreement, dated as of October 7, 2025, by and among the Issuer and the investors party thereto, pursuant to which the Trust acquired 36,928 shares of common stock at a purchase price of $20.85 per share."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"The reporting person is a Trustee of the Trust and may be deemed to have voting and dispositive power over the shares held by the Trust. The reporting person is the Issuer's chief executive officer and Chairman of its board of directors. The reporting person disclaims beneficial ownership of such securities except to the extent of his pecuniary interest therein."}],"balance_after":36928,"source":{"system":"sec-edgar","filing":"0001104659-25-098413","document":"tm2528454-2_4seq1.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1228865/000110465925098413/tm2528454-2_4seq1.xml","form_type":"4"}},{"id":1020686,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":2222,"kind":"person","name":"Fairmount Funds Management LLC","position":1,"cik":"0001802528","reported_name":"Fairmount Funds Management LLC","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}},{"id":2223,"kind":"person","name":"Fairmount Healthcare Fund II L.P.","position":2,"cik":"0001769651","reported_name":"Fairmount Healthcare Fund II L.P.","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}},{"id":2224,"kind":"person","name":"Kiselak Tomas","position":3,"cik":"0001830177","reported_name":"Kiselak Tomas","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}},{"id":2225,"kind":"person","name":"Harwin Peter Evan","position":4,"cik":"0001663607","reported_name":"Harwin Peter Evan","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common Stock","published_at":"2025-10-09T20:15:16.000Z","date":"2025-10-07","kind":"purchase","planned":false,"acquired":true,"shares":316219,"price":19,"value":6008161.0,"ownership":{"direct":false,"nature":"By Fairmount Healthcare Fund II L.P."},"footnotes":[{"field":"ownership.nature","element":"natureOfOwnership","label":"F1","text":"Fairmount Funds Management LLC (\"Fairmount\") is the investment manager for Fairmount Healthcare Fund II L.P. The managers of Fairmount are Peter Harwin and Tomas Kiselak. Fairmount, Mr. Harwin, and Mr. Kiselak disclaim beneficial ownership of any of the reported\nsecurities, except to the extent of their pecuniary interest therein."}],"balance_after":2209025,"source":{"system":"sec-edgar","filing":"0001104659-25-098362","document":"tm2528449-1_4seq1.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1663607/000110465925098362/tm2528449-1_4seq1.xml","form_type":"4"}},{"id":1020672,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":37101,"kind":"person","name":"Lu Hongbo","position":1,"cik":"0001767584","reported_name":"Lu Hongbo","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common Stock","published_at":"2025-10-09T19:37:06.000Z","date":"2025-10-07","kind":"purchase","planned":false,"acquired":true,"shares":263160,"price":19,"value":5000040.0,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"ownership.direct","element":"directOrIndirectOwnership","label":"F2","text":"The reported securities are owned directly by NEXTBio Master Fund LP or NextBio Evergreen LLC and may be deemed to be indirectly beneficially owned by (i) NEXTBio Capital LLC, the general partner of NEXTBio Master Fund LP (with respect to such securities directly owned by NEXTBio Master Fund LP), (ii) NEXTBio Capital Evergreen GP LLC, the managing member of NEXTBio Evergreen LLC (with respect to such securities directly owned by NextBio Evergreen LLC), (iii) NEXTBio Capital Management LP, the investment manager to NEXTBio Master Fund LP and NextBio Evergreen LLC, and (iv) Hongbo Lu, a managing member of NEXTBio Capital LLC and NEXTBio Capital Evergreen GP LLC."},{"field":"ownership.direct","element":"directOrIndirectOwnership","label":"F3","text":"(Continued from footnote 2) The Reporting Person disclaims beneficial ownership of the reported securities except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of the securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"The reported securities are owned directly by NEXTBio Master Fund LP or NextBio Evergreen LLC and may be deemed to be indirectly beneficially owned by (i) NEXTBio Capital LLC, the general partner of NEXTBio Master Fund LP (with respect to such securities directly owned by NEXTBio Master Fund LP), (ii) NEXTBio Capital Evergreen GP LLC, the managing member of NEXTBio Evergreen LLC (with respect to such securities directly owned by NextBio Evergreen LLC), (iii) NEXTBio Capital Management LP, the investment manager to NEXTBio Master Fund LP and NextBio Evergreen LLC, and (iv) Hongbo Lu, a managing member of NEXTBio Capital LLC and NEXTBio Capital Evergreen GP LLC."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"(Continued from footnote 2) The Reporting Person disclaims beneficial ownership of the reported securities except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of the securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose."}],"balance_after":321983,"source":{"system":"sec-edgar","filing":"0000919574-25-006031","document":"ownership.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1767584/000091957425006031/ownership.xml","form_type":"4"}},{"id":1020671,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":37101,"kind":"person","name":"Lu Hongbo","position":1,"cik":"0001767584","reported_name":"Lu Hongbo","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common Stock","published_at":"2025-10-09T19:37:06.000Z","date":"2024-09-13","kind":"purchase","planned":false,"acquired":true,"shares":58823,"price":17,"value":999991.0,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"ownership.direct","element":"directOrIndirectOwnership","label":"F1","text":"The reported securities are owned directly by NEXTBio Master Fund LP and may be deemed to be indirectly beneficially owned by (i) NEXTBio Capital LLC, the general partner of NEXTBio Master Fund LP, (ii) NEXTBio Capital Management LP, the investment manager to NEXTBio Master Fund LP, and (iii) Hongbo Lu, a managing member of NEXTBio Capital LLC. The Reporting Person disclaims beneficial ownership of the reported securities except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of the securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F1","text":"The reported securities are owned directly by NEXTBio Master Fund LP and may be deemed to be indirectly beneficially owned by (i) NEXTBio Capital LLC, the general partner of NEXTBio Master Fund LP, (ii) NEXTBio Capital Management LP, the investment manager to NEXTBio Master Fund LP, and (iii) Hongbo Lu, a managing member of NEXTBio Capital LLC. The Reporting Person disclaims beneficial ownership of the reported securities except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of the securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose."}],"balance_after":58823,"source":{"system":"sec-edgar","filing":"0000919574-25-006031","document":"ownership.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1767584/000091957425006031/ownership.xml","form_type":"4"}},{"id":1113215,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":10038,"kind":"person","name":"Nunn Jason Raleigh","position":1,"cik":"0001444319","reported_name":"Nunn Jason Raleigh","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Stock Option (Right to Buy)","published_at":"2025-06-12T20:58:46.000Z","date":"2025-06-10","kind":"grant","planned":false,"acquired":true,"shares":18500,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The option vests as to 100% of the underlying shares of common stock on June 10, 2026, the first anniversary of the vesting commencement date, subject to continued service."}],"balance_after":18500,"derivative":{"exercise_price":11.94,"expiration_date":"2035-06-10","underlying":"Common Stock","underlying_shares":18500},"source":{"system":"sec-edgar","filing":"0000950170-25-085531","document":"ownership.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1444319/000095017025085531/ownership.xml","form_type":"4"}},{"id":1112774,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":1945,"kind":"person","name":"Fox Jennifer A.","position":1,"cik":"0001841557","reported_name":"Fox Jennifer A.","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"See Remarks"}}],"security":"Stock Option (Right to Buy)","published_at":"2025-06-12T20:38:35.000Z","date":"2025-06-10","kind":"grant","planned":false,"acquired":true,"shares":150000,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The option vests as to 25% of the underlying shares of common stock on June 10, 2026, the first anniversary of the vesting commencement date, and as to the remaining shares, in equal month installments over 36 months thereafter, subject to continued service."}],"balance_after":150000,"derivative":{"exercise_price":11.94,"expiration_date":"2035-06-10","underlying":"Common Stock","underlying_shares":150000},"source":{"system":"sec-edgar","filing":"0001104659-25-058943","document":"tm2517684-10_4seq1.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1841557/000110465925058943/tm2517684-10_4seq1.xml","form_type":"4"}},{"id":1112769,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":37074,"kind":"person","name":"Boylan James P","position":1,"cik":"0001953094","reported_name":"Boylan James P","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Stock Option (Right to Buy)","published_at":"2025-06-12T20:36:42.000Z","date":"2025-06-10","kind":"grant","planned":false,"acquired":true,"shares":18500,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The option vests as to 100% of the underlying shares of common stock on June 10, 2026, the first anniversary of the vesting commencement date, subject to continued service."},{"field":"ownership.direct","element":"directOrIndirectOwnership","label":"F2","text":"The reporting person holds the stock option, and the shares underlying the option, for the benefit of Enavate Sciences, LP. Accordingly, the reporting person disclaims beneficial ownership of the reported securities except to the extent of his pecuniary interest therein, if any."}],"balance_after":18500,"derivative":{"exercise_price":11.94,"expiration_date":"2035-06-10","underlying":"Common Stock","underlying_shares":18500},"source":{"system":"sec-edgar","filing":"0001104659-25-058935","document":"tm2517684-8_4seq1.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1953094/000110465925058935/tm2517684-8_4seq1.xml","form_type":"4"}},{"id":1113005,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":37171,"kind":"person","name":"Allen Patricia L","position":1,"cik":"0001348587","reported_name":"Allen Patricia L","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Stock Option (Right to Buy)","published_at":"2025-06-12T20:35:55.000Z","date":"2025-06-10","kind":"grant","planned":false,"acquired":true,"shares":18500,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The option vests as to 100% of the underlying shares of common stock on June 10, 2026, the first anniversary of the vesting commencement date, subject to continued service."}],"balance_after":18500,"derivative":{"exercise_price":11.94,"expiration_date":"2035-06-10","underlying":"Common Stock","underlying_shares":18500},"source":{"system":"sec-edgar","filing":"0001104659-25-058933","document":"tm2517684-7_4seq1.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1348587/000110465925058933/tm2517684-7_4seq1.xml","form_type":"4"}},{"id":1113029,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":37175,"kind":"person","name":"Farmer Joseph L","position":1,"cik":"0001317757","reported_name":"Farmer Joseph L","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"See Remarks"}}],"security":"Stock Option (Right to Buy)","published_at":"2025-06-12T20:35:06.000Z","date":"2025-06-10","kind":"grant","planned":false,"acquired":true,"shares":175000,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The option vests as to 25% of the underlying shares of common stock on June 10, 2026, the first anniversary of the vesting commencement date, and as to the remaining shares, in equal month installments over 36 months thereafter, subject to continued service."}],"balance_after":175000,"derivative":{"exercise_price":11.94,"expiration_date":"2035-06-10","underlying":"Common Stock","underlying_shares":175000},"source":{"system":"sec-edgar","filing":"0001104659-25-058930","document":"tm2517684-6_4seq1.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1317757/000110465925058930/tm2517684-6_4seq1.xml","form_type":"4"}},{"id":1112844,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":2222,"kind":"person","name":"Fairmount Funds Management LLC","position":1,"cik":"0001802528","reported_name":"Fairmount Funds Management LLC","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}},{"id":2223,"kind":"person","name":"Fairmount Healthcare Fund II L.P.","position":2,"cik":"0001769651","reported_name":"Fairmount Healthcare Fund II L.P.","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}},{"id":2224,"kind":"person","name":"Kiselak Tomas","position":3,"cik":"0001830177","reported_name":"Kiselak Tomas","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}},{"id":2225,"kind":"person","name":"Harwin Peter Evan","position":4,"cik":"0001663607","reported_name":"Harwin Peter Evan","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Stock Option (Right to Buy)","published_at":"2025-06-12T20:34:14.000Z","date":"2025-06-10","kind":"grant","planned":false,"acquired":true,"shares":18500,"price":0,"value":0.0,"ownership":{"direct":false,"nature":"By Tomas Kiselak"},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The option vests as to 100% of the underlying shares of common stock on June 10, 2026, the first anniversary of the vesting commencement date, subject to continued service."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Under Mr. Kiselak's arrangement with Fairmount, Mr. Kiselak holds the option for one or more investment vehicles managed by Fairmount Funds Management LLC (\"Fairmount\" and each such investment vehicle, a \"Fairmount Fund\"). Mr. Kiselak is obligated to turn over to Fairmount any net cash or stock received from the option for the benefit of such Fairmount Fund. Mr. Kiselak therefore disclaims beneficial ownership of the option and underlying common stock. Fairmount disclaims beneficial ownership of any of the reported securities, except to the extent of its pecuniary interest therein."}],"balance_after":18500,"derivative":{"exercise_price":11.94,"expiration_date":"2035-06-10","underlying":"Common Stock","underlying_shares":18500},"source":{"system":"sec-edgar","filing":"0001104659-25-058927","document":"tm2517684-5_4seq1.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1663607/000110465925058927/tm2517684-5_4seq1.xml","form_type":"4"}},{"id":1113041,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":847,"kind":"person","name":"ENRIGHT PATRICK G","position":1,"cik":"0001253886","reported_name":"ENRIGHT PATRICK G","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Stock Option (Right to 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These shares were purchased in multiple transactions ranging from $7.64 to $7.78, inclusive. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"This Form 4/A is filed solely to amend the previous Form 4 filed by the Reporting Person on February 11, 2025, which incorrectly reported in column 5 of Table I the amount of securities beneficially owned following reported transactions as 47,000 shares. The correct amount of securities beneficially owned following the reported transactions is 10,000 shares."}],"balance_after":10000,"source":{"system":"sec-edgar","filing":"0001104659-25-039771","document":"tm2513284-1_4aseq1.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/2035283/000110465925039771/tm2513284-1_4aseq1.xml","form_type":"4/A","original_submission_date":"2025-02-11"}},{"id":1170516,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":37467,"kind":"person","name":"von Moltke Lisa","position":1,"cik":"0001808592","reported_name":"von Moltke Lisa","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"See Remarks"}}],"security":"Stock Option (Right to Buy)","published_at":"2025-04-17T20:01:17.000Z","date":"2025-04-15","kind":"grant","planned":false,"acquired":true,"shares":400000,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The option vests as to 25% of the underlying shares of common stock on March 17, 2025, the first anniversary of the vesting commencement date, and as to the remaining shares, in equal month installments over 36 months thereafter, subject to continued service."}],"balance_after":400000,"derivative":{"exercise_price":8.72,"expiration_date":"2035-04-14","underlying":"Common Stock","underlying_shares":400000},"source":{"system":"sec-edgar","filing":"0001104659-25-035996","document":"tm2512517-1_4seq1.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1808592/000110465925035996/tm2512517-1_4seq1.xml","form_type":"4"}},{"id":1259229,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":36288,"kind":"person","name":"MOULDER LEON O JR","position":1,"cik":"0001228865","reported_name":"MOULDER LEON O JR","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Executive Officer"}}],"security":"Common Stock","published_at":"2025-02-19T21:01:11.000Z","date":"2025-02-18","kind":"purchase","planned":false,"acquired":true,"shares":25000,"price":6.67,"value":166750.0,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The price reported is a weighted average price. 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The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range."}],"balance_after":266155,"source":{"system":"sec-edgar","filing":"0001104659-25-015145","document":"tm257089-1_4seq1.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1228865/000110465925015145/tm257089-1_4seq1.xml","form_type":"4"}},{"id":1274331,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":80458,"kind":"person","name":"Xiao Ting","position":1,"cik":"0002035283","reported_name":"Xiao Ting","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common Stock","published_at":"2025-02-11T16:20:30.000Z","date":"2025-02-07","kind":"purchase","planned":false,"acquired":true,"shares":10000,"price":7.76,"value":77600.0,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The price reported is a weighted average price. These shares were purchased in multiple transactions ranging from $7.64 to $7.78, inclusive. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range."}],"balance_after":47000,"source":{"system":"sec-edgar","filing":"0001104659-25-011505","document":"tm256174-1_4seq1.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/2035283/000110465925011505/tm256174-1_4seq1.xml","form_type":"4"}},{"id":1326084,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":1945,"kind":"person","name":"Fox Jennifer A.","position":1,"cik":"0001841557","reported_name":"Fox Jennifer A.","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"See Remarks"}}],"security":"Stock Option (Right to Buy)","published_at":"2024-12-18T21:31:27.000Z","date":"2024-12-16","kind":"grant","planned":false,"acquired":true,"shares":8125,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The option vests as to 25% of the underlying shares of common stock on September 12, 2025, the first anniversary of the vesting commencement date, and as to the remaining shares, in equal month installments over 36 months thereafter, subject to continued service."}],"balance_after":8125,"derivative":{"exercise_price":8.77,"expiration_date":"2034-12-15","underlying":"Common Stock","underlying_shares":8125},"source":{"system":"sec-edgar","filing":"0001104659-24-129778","document":"tm2431489-2_4seq1.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1841557/000110465924129778/tm2431489-2_4seq1.xml","form_type":"4"}},{"id":1326168,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":78543,"kind":"person","name":"Oliveira Orlando","position":1,"cik":"0001699305","reported_name":"Oliveira Orlando","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Commercial Officer"}}],"security":"Stock Option (Right to Buy)","published_at":"2024-12-18T16:30:14.000Z","date":"2024-12-16","kind":"grant","planned":false,"acquired":true,"shares":7775,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The option vests as to 25% of the underlying shares of common stock on July 1, 2025, the first anniversary of the vesting commencement date, and as to the remaining shares, in equal month installments over 36 months thereafter, subject to continued service."}],"balance_after":7775,"derivative":{"exercise_price":8.77,"expiration_date":"2034-12-15","underlying":"Common Stock","underlying_shares":7775},"source":{"system":"sec-edgar","filing":"0001104659-24-129776","document":"tm2431489-1_4seq1.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1699305/000110465924129776/tm2431489-1_4seq1.xml","form_type":"4"}},{"id":1342719,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":36288,"kind":"person","name":"MOULDER LEON O JR","position":1,"cik":"0001228865","reported_name":"MOULDER LEON O JR","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Executive Officer"}}],"security":"Common Stock","published_at":"2024-12-05T02:03:46.000Z","date":"2024-12-04","kind":"purchase","planned":false,"acquired":true,"shares":45000,"price":9.98,"value":449100.0,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported is a weighted average price. 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The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range."}],"balance_after":241155,"source":{"system":"sec-edgar","filing":"0001104659-24-125677","document":"tm2430232-1_4seq1.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1228865/000110465924125677/tm2430232-1_4seq1.xml","form_type":"4"}},{"id":1342718,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":36288,"kind":"person","name":"MOULDER LEON O JR","position":1,"cik":"0001228865","reported_name":"MOULDER LEON O JR","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Executive Officer"}}],"security":"Common Stock","published_at":"2024-12-05T02:03:46.000Z","date":"2024-12-03","kind":"purchase","planned":false,"acquired":true,"shares":25000,"price":10.76,"value":269000.0,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The price reported is a weighted average price. These shares were purchased in multiple transactions ranging from $10.73 to $10.88, inclusive. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range."}],"balance_after":196155,"source":{"system":"sec-edgar","filing":"0001104659-24-125677","document":"tm2430232-1_4seq1.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1228865/000110465924125677/tm2430232-1_4seq1.xml","form_type":"4"}},{"id":1357030,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":36288,"kind":"person","name":"MOULDER LEON O JR","position":1,"cik":"0001228865","reported_name":"MOULDER LEON O JR","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Executive Officer"}}],"security":"Common Stock","published_at":"2024-11-20T22:20:29.000Z","date":"2024-11-19","kind":"purchase","planned":false,"acquired":true,"shares":2500,"price":14.57,"value":36425.0,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported is a weighted average price. These shares were purchased in multiple transactions ranging from $14.50 to $14.62, inclusive. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range."}],"balance_after":171155,"source":{"system":"sec-edgar","filing":"0001104659-24-121081","document":"tm2429053-1_4seq1.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1228865/000110465924121081/tm2429053-1_4seq1.xml","form_type":"4"}},{"id":1357029,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":36288,"kind":"person","name":"MOULDER LEON O JR","position":1,"cik":"0001228865","reported_name":"MOULDER LEON O JR","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Executive Officer"}}],"security":"Common Stock","published_at":"2024-11-20T22:20:29.000Z","date":"2024-11-18","kind":"purchase","planned":false,"acquired":true,"shares":7500,"price":15,"value":112500.0,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"The price reported is a weighted average price. These shares were purchased in multiple transactions ranging from $14.81 to $15.32, inclusive. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range."}],"balance_after":168655,"source":{"system":"sec-edgar","filing":"0001104659-24-121081","document":"tm2429053-1_4seq1.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1228865/000110465924121081/tm2429053-1_4seq1.xml","form_type":"4"}},{"id":1401505,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":36288,"kind":"person","name":"MOULDER LEON O JR","position":1,"cik":"0001228865","reported_name":"MOULDER LEON O JR","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Executive Officer"}}],"security":"Common Stock","published_at":"2024-09-20T22:34:18.000Z","date":"2024-09-20","kind":"purchase","planned":false,"acquired":true,"shares":2633,"price":18.97,"value":49948.01,"ownership":{"direct":false,"nature":"See Footnote"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F5","text":"The price reported is a weighted average price. These shares were purchased in multiple transactions ranging from $18.35 to $19.24, inclusive. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Leon O. Moulder, Jr. is the Managing Member of Tellus BioVentures LLC (\"Tellus\") and may be deemed to have sole voting and dispositive power over the shares held by Tellus. Mr. Moulder is the Issuer's chief executive officer and Chairman of its board of directors. Mr. Moulder disclaims beneficial ownership of such securities except to the extent of his pecuniary interest therein."}],"balance_after":1672039,"source":{"system":"sec-edgar","filing":"0001104659-24-101773","document":"tm2424498-1_4seq1.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":4,"url":"https://www.sec.gov/Archives/edgar/data/1228865/000110465924101773/tm2424498-1_4seq1.xml","form_type":"4"}},{"id":1401504,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":36288,"kind":"person","name":"MOULDER LEON O JR","position":1,"cik":"0001228865","reported_name":"MOULDER LEON O JR","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Executive Officer"}}],"security":"Common Stock","published_at":"2024-09-20T22:34:18.000Z","date":"2024-09-20","kind":"purchase","planned":false,"acquired":true,"shares":2367,"price":17.88,"value":42321.96,"ownership":{"direct":false,"nature":"See Footnote"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F4","text":"The price reported is a weighted average price. These shares were purchased in multiple transactions ranging from $17.70 to $18.27, inclusive. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F2","text":"Leon O. Moulder, Jr. is the Managing Member of Tellus BioVentures LLC (\"Tellus\") and may be deemed to have sole voting and dispositive power over the shares held by Tellus. Mr. Moulder is the Issuer's chief executive officer and Chairman of its board of directors. 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Enavate disclaims beneficial ownership of these shares except to the extent of its pecuniary interest therein, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of the reported securities for purposes of Section 16 or for any other purpose."}],"balance_after":2879006,"source":{"system":"sec-edgar","filing":"0001415889-24-023609","document":"form4-09182024_040906.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/2037042/000141588924023609/form4-09182024_040906.xml","form_type":"4"}},{"id":1403089,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":87410,"kind":"organization","name":"Wellington Biomedical Innovation Master Investors (Cayman) I L.P.","position":1,"cik":"0001787092","reported_name":"Wellington Biomedical Innovation Master Investors (Cayman) I L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series C Convertible Preferred Stock","published_at":"2024-09-18T17:16:21.000Z","date":"2024-09-16","kind":"exercise","planned":false,"acquired":false,"shares":1742858,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F3","text":"On September 16, 2024, the shares of Series C Convertible Preferred Stock automatically converted into shares of Common Stock on a 8.6831-for-1 basis without payment of further consideration upon the closing of the Issuer's initial public offering. 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The shares have no expiration date."},{"field":"price","element":"transactionPricePerShare","label":"F5","text":"On September 16, 2024, the shares of Series B Convertible Preferred Stock automatically converted into shares of Common Stock on a 8.6831-for-1 basis without payment of further consideration upon the closing of the Issuer's initial public offering. The shares have no expiration date."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F5","text":"On September 16, 2024, the shares of Series B Convertible Preferred Stock automatically converted into shares of Common Stock on a 8.6831-for-1 basis without payment of further consideration upon the closing of the Issuer's initial public offering. The shares have no expiration date."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F5","text":"On September 16, 2024, the shares of Series B Convertible Preferred Stock automatically converted into shares of Common Stock on a 8.6831-for-1 basis without payment of further consideration upon the closing of the Issuer's initial public offering. 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The shares have no expiration date."},{"field":"price","element":"transactionPricePerShare","label":"F5","text":"On September 16, 2024, the shares of Series B Convertible Preferred Stock automatically converted into shares of Common Stock on a 8.6831-for-1 basis without payment of further consideration upon the closing of the Issuer's initial public offering. The shares have no expiration date."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F5","text":"On September 16, 2024, the shares of Series B Convertible Preferred Stock automatically converted into shares of Common Stock on a 8.6831-for-1 basis without payment of further consideration upon the closing of the Issuer's initial public offering. The shares have no expiration date."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F5","text":"On September 16, 2024, the shares of Series B Convertible Preferred Stock automatically converted into shares of Common Stock on a 8.6831-for-1 basis without payment of further consideration upon the closing of the Issuer's initial public offering. The shares have no expiration date."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"Leon O. Moulder, Jr. is the Managing Member of Tellus BioVentures LLC (\"Tellus\") and may be deemed to have sole voting and dispositive power over the shares held by Tellus. Mr. Moulder is the Issuer's chief executive officer and Chairman of its board of directors. 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The shares have no expiration date."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F4","text":"On September 16, 2024, the shares of Series A Convertible Preferred Stock automatically converted into shares of Common Stock on a 8.6831-for-1 basis without payment of further consideration upon the closing of the Issuer's initial public offering. The shares have no expiration date."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F4","text":"On September 16, 2024, the shares of Series A Convertible Preferred Stock automatically converted into shares of Common Stock on a 8.6831-for-1 basis without payment of further consideration upon the closing of the Issuer's initial public offering. 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The shares have no expiration date."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"On September 16, 2024, the shares of Series Seed Convertible Preferred Stock automatically converted into shares of Common Stock on a 8.6831-for-1 basis without payment of further consideration upon the closing of the Issuer's initial public offering. The shares have no expiration date."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"Leon O. Moulder, Jr. is the Managing Member of Tellus BioVentures LLC (\"Tellus\") and may be deemed to have sole voting and dispositive power over the shares held by Tellus. Mr. Moulder is the Issuer's chief executive officer and Chairman of its board of directors. 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The shares have no expiration date."},{"field":"price","element":"transactionPricePerShare","label":"F5","text":"On September 16, 2024, the shares of Series B Convertible Preferred Stock automatically converted into shares of Common Stock on a 8.6831-for-1 basis without payment of further consideration upon the closing of the Issuer's initial public offering. The shares have no expiration date."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"This amendment is being filed solely to correct the previously reported \"Amount of Securities Beneficially Owned Following Reported Transactions.\" This amended Form 4 does not report any new transactions or otherwise modify the transaction details that were previously reported."}],"balance_after":161155,"source":{"system":"sec-edgar","filing":"0001104659-24-100765","document":"tm2424157-14_4aseq1.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":4,"url":"https://www.sec.gov/Archives/edgar/data/1228865/000110465924100765/tm2424157-14_4aseq1.xml","form_type":"4/A","original_submission_date":"2024-09-16"}},{"id":1404864,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":36288,"kind":"person","name":"MOULDER LEON O JR","position":1,"cik":"0001228865","reported_name":"MOULDER LEON O JR","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Executive Officer"}}],"security":"Common Stock","published_at":"2024-09-18T00:54:38.000Z","date":"2024-09-16","kind":"exercise","planned":false,"acquired":true,"shares":372017,"ownership":{"direct":false,"nature":"See Footnote"},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F5","text":"On September 16, 2024, the shares of Series B Convertible Preferred Stock automatically converted into shares of Common Stock on a 8.6831-for-1 basis without payment of further consideration upon the closing of the Issuer's initial public offering. The shares have no expiration date."},{"field":"price","element":"transactionPricePerShare","label":"F5","text":"On September 16, 2024, the shares of Series B Convertible Preferred Stock automatically converted into shares of Common Stock on a 8.6831-for-1 basis without payment of further consideration upon the closing of the Issuer's initial public offering. The shares have no expiration date."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"This amendment is being filed solely to correct the previously reported \"Amount of Securities Beneficially Owned Following Reported Transactions.\" This amended Form 4 does not report any new transactions or otherwise modify the transaction details that were previously reported."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"Leon O. 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The shares have no expiration date."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"This amendment is being filed solely to correct the previously reported \"Amount of Securities Beneficially Owned Following Reported Transactions.\" This amended Form 4 does not report any new transactions or otherwise modify the transaction details that were previously reported."}],"balance_after":112901,"source":{"system":"sec-edgar","filing":"0001104659-24-100765","document":"tm2424157-14_4aseq1.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1228865/000110465924100765/tm2424157-14_4aseq1.xml","form_type":"4/A","original_submission_date":"2024-09-16"}},{"id":1404862,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":36288,"kind":"person","name":"MOULDER LEON O JR","position":1,"cik":"0001228865","reported_name":"MOULDER LEON O JR","relationship":{"director":true,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Executive Officer"}}],"security":"Common Stock","published_at":"2024-09-18T00:54:38.000Z","date":"2024-09-16","kind":"exercise","planned":false,"acquired":true,"shares":164523,"ownership":{"direct":false,"nature":"See Footnote"},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"On September 16, 2024, the shares of Series Seed Convertible Preferred Stock automatically converted into shares of Common Stock on a 8.6831-for-1 basis without payment of further consideration upon the closing of the Issuer's initial public offering. The shares have no expiration date."},{"field":"price","element":"transactionPricePerShare","label":"F1","text":"On September 16, 2024, the shares of Series Seed Convertible Preferred Stock automatically converted into shares of Common Stock on a 8.6831-for-1 basis without payment of further consideration upon the closing of the Issuer's initial public offering. The shares have no expiration date."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"This amendment is being filed solely to correct the previously reported \"Amount of Securities Beneficially Owned Following Reported Transactions.\" This amended Form 4 does not report any new transactions or otherwise modify the transaction details that were previously reported."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"Leon O. Moulder, Jr. is the Managing Member of Tellus BioVentures LLC (\"Tellus\") and may be deemed to have sole voting and dispositive power over the shares held by Tellus. Mr. Moulder is the Issuer's chief executive officer and Chairman of its board of directors. Mr. Moulder disclaims beneficial ownership of such securities except to the extent of his pecuniary interest therein."}],"balance_after":1280022,"source":{"system":"sec-edgar","filing":"0001104659-24-100765","document":"tm2424157-14_4aseq1.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1228865/000110465924100765/tm2424157-14_4aseq1.xml","form_type":"4/A","original_submission_date":"2024-09-16"}},{"id":1404493,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":37101,"kind":"person","name":"Lu Hongbo","position":1,"cik":"0001767584","reported_name":"Lu Hongbo","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common Stock","published_at":"2024-09-17T23:52:28.000Z","date":"2024-09-13","kind":"purchase","planned":false,"acquired":true,"shares":58823,"price":17,"value":999991.0,"ownership":{"direct":false,"nature":"See footnote"},"footnotes":[{"field":"ownership.nature","element":"natureOfOwnership","label":"F1","text":"The reported securities are owned directly by NEXTBio Master Fund LP and may be deemed to be indirectly beneficially owned by (i) NEXTBio Capital LLC, the general partner of NEXTBio Master Fund LP, (ii) NEXTBio Capital Management LP, the investment manager to NEXTBio Master Fund LP, and (iii) Hongbo Lu, a managing member of NEXTBio Capital LLC. The Reporting Person disclaims beneficial ownership of the reported securities except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that the Reporting Person is the beneficial owners of the securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose."}],"balance_after":58823,"source":{"system":"sec-edgar","filing":"0000919574-24-005530","document":"ownership.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1767584/000091957424005530/ownership.xml","form_type":"4"}},{"id":1406344,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":37121,"kind":"person","name":"ORLOFF JOHN J","position":1,"cik":"0001643941","reported_name":"ORLOFF JOHN 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three years beginning on September 12, 2025, the first anniversary of the vesting commencement date, subject to continued service."}],"balance_after":37000,"derivative":{"exercise_price":17,"expiration_date":"2034-09-11","underlying":"Common Stock","underlying_shares":37000},"source":{"system":"sec-edgar","filing":"0001104659-24-100337","document":"tm2424157-10_4seq1.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1767584/000110465924100337/tm2424157-10_4seq1.xml","form_type":"4"}},{"id":1406465,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":37171,"kind":"person","name":"Allen Patricia L","position":1,"cik":"0001348587","reported_name":"Allen Patricia L","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Stock Option (Right to 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Inc.","symbol":"ZBIO"},"owners":[{"id":847,"kind":"person","name":"ENRIGHT PATRICK G","position":1,"cik":"0001253886","reported_name":"ENRIGHT PATRICK G","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Stock Option (Right to Buy)","published_at":"2024-09-17T00:57:32.000Z","date":"2024-09-12","kind":"grant","planned":false,"acquired":true,"shares":37000,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F6","text":"The option vests in equal annual installments over three years beginning on September 12, 2025, the first anniversary of the vesting commencement date, subject to continued service."}],"balance_after":37000,"derivative":{"exercise_price":17,"expiration_date":"2034-09-11","underlying":"Common 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September 16, 2024, the shares of Series C Convertible Preferred Stock automatically converted into shares of Common Stock on a 8.6831-for-1 basis without payment of further consideration upon the closing of the Issuer's initial public offering. The shares have no expiration date."},{"field":"shares","element":"transactionShares","label":"F5","text":"Shares held by LPF."},{"field":"price","element":"transactionPricePerShare","label":"F1","text":"On September 16, 2024, the shares of Series B Convertible Preferred Stock automatically converted into shares of Common Stock on a 8.6831-for-1 basis without payment of further consideration upon the closing of the Issuer's initial public offering. The shares have no expiration date."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F4","text":"On September 16, 2024, the shares of Series C Convertible Preferred Stock automatically converted into shares of Common Stock on a 8.6831-for-1 basis without payment of further consideration upon the closing of the Issuer's initial public offering. The shares have no expiration date."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F4","text":"On September 16, 2024, the shares of Series C Convertible Preferred Stock automatically converted into shares of Common Stock on a 8.6831-for-1 basis without payment of further consideration upon the closing of the Issuer's initial public offering. The shares have no expiration date."},{"field":"derivative.underlying_shares","element":"underlyingSecurityShares","label":"F5","text":"Shares held by LPF."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"Longitude Capital Partners IV, LLC (\"LCPIV\") is the general partner of LVPIV and may be deemed to have voting, investment and dispositive power with respect to these securities. Longitude Prime Partners, LLC (\"LPP\") is the general partner of Longitude Prime Fund, L.P. (\"LPF\") and may be deemed to have voting, investment and dispositive power with respect to the securities held by LPF. Juliet Tammenoms Bakker and Patrick G. Enright, a member of the board of directors of the Issuer, are the managing members of LCPIV and LPP and may each be deemed to share voting, investment and dispositive power with respect to these securities. Each of LCPIV, LPP, Ms. Bakker and Mr. Enright disclaims beneficial ownership of such securities except to the extent of their respective pecuniary interests therein."}],"balance_after":0,"derivative":{"underlying":"Common Stock","underlying_shares":334530},"source":{"system":"sec-edgar","filing":"0001104659-24-100333","document":"tm2424157-3_4seq1.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":7,"url":"https://www.sec.gov/Archives/edgar/data/1253886/000110465924100333/tm2424157-3_4seq1.xml","form_type":"4"}},{"id":1406493,"issuer":{"id":275,"kind":"organization","name":"Zenas BioPharma, Inc.","symbol":"ZBIO"},"owners":[{"id":847,"kind":"person","name":"ENRIGHT PATRICK G","position":1,"cik":"0001253886","reported_name":"ENRIGHT PATRICK G","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Series C Convertible Preferred Stock","published_at":"2024-09-17T00:57:32.000Z","date":"2024-09-16","kind":"exercise","planned":false,"acquired":false,"shares":8714293,"ownership":{"direct":false,"nature":"See Footnote"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F4","text":"On September 16, 2024, the shares of Series C Convertible Preferred Stock automatically converted into shares of Common Stock on a 8.6831-for-1 basis without payment of further consideration upon the closing of the Issuer's initial public offering. The shares have no expiration date."},{"field":"shares","element":"transactionShares","label":"F2","text":"Shares held by Longitude Venture Partners IV, L.P. (\"LVPIV\")."},{"field":"price","element":"transactionPricePerShare","label":"F1","text":"On September 16, 2024, the shares of Series B Convertible Preferred Stock automatically converted into shares of Common Stock on a 8.6831-for-1 basis without payment of further consideration upon the closing of the Issuer's initial public offering. The shares have no expiration date."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F4","text":"On September 16, 2024, the shares of Series C Convertible Preferred Stock automatically converted into shares of Common Stock on a 8.6831-for-1 basis without payment of further consideration upon the closing of the Issuer's initial public offering. The shares have no expiration date."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F4","text":"On September 16, 2024, the shares of Series C Convertible Preferred Stock automatically converted into shares of Common Stock on a 8.6831-for-1 basis without payment of further consideration upon the closing of the Issuer's initial public offering. The shares have no expiration date."},{"field":"derivative.underlying_shares","element":"underlyingSecurityShares","label":"F2","text":"Shares held by Longitude Venture Partners IV, L.P. (\"LVPIV\")."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"Longitude Capital Partners IV, LLC (\"LCPIV\") is the general partner of LVPIV and may be deemed to have voting, investment and dispositive power with respect to these securities. Longitude Prime Partners, LLC (\"LPP\") is the general partner of Longitude Prime Fund, L.P. (\"LPF\") and may be deemed to have voting, investment and dispositive power with respect to the securities held by LPF. Juliet Tammenoms Bakker and Patrick G. Enright, a member of the board of directors of the Issuer, are the managing members of LCPIV and LPP and may each be deemed to share voting, investment and dispositive power with respect to these securities. Each of LCPIV, LPP, Ms. Bakker and Mr. Enright disclaims beneficial ownership of such securities except to the extent of their respective pecuniary interests therein."}],"balance_after":0,"derivative":{"underlying":"Common Stock","underlying_shares":1003592},"source":{"system":"sec-edgar","filing":"0001104659-24-100333","document":"tm2424157-3_4seq1.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":6,"url":"https://www.sec.gov/Archives/edgar/data/1253886/000110465924100333/tm2424157-3_4seq1.xml","form_type":"4"}}],"next_cursor":"2024-09-17T00:57:32.000000Z,1406493"}