SCHEDULE 13D/A 0001845246 XXXXXXXX LIVE 2 Ordinary Shares, par value $0.0001 per share (Including Ordinary Shares Underlying American Depository Shares) 01/29/2026 false 0001778016 44975P103 NovaBridge Biosciences

SUITE 400, 2440 RESEARCH BLVD ROCKVILLE MD 20850

Jianming Ma 86 21 80123200 c/o CBC Group, 62F Tower 1, Plaza 66 1266 West Nanjing Shanghai F4 200040 0001845246 N CBC Investment I-Mab Limited b OO N D8 0.00 11784164.00 0.00 11784164.00 11784164.00 Y 4.4 CO Y IBC Investment Seven Limited b OO N K3 0.00 3641554.00 0.00 3641554.00 3641554 Y 1.4 CO Y CBC SPVII LIMITED b OO N K3 0.00 5574560.00 0.00 5574560.00 5574560.00 Y 2.1 CO Y C-Bridge II Investment Ten Limited b OO N D8 0.00 2369546.00 0.00 2369546.00 2369546.00 Y 0.9 CO Y Nova Aqua Limited b OO N D8 0.00 7129885.00 0.00 7129885.00 7129885.00 Y 2.7 CO Y C-Bridge Healthcare Fund II, L.P. b OO N E9 0.00 14153710.00 0.00 14153710.00 14153710.00 Y 5.3 PN Y C-Bridge Healthcare Fund GP II, L.P. b OO N E9 0.00 14153710.00 0.00 14153710.00 14153710.00 Y 5.3 PN Y C-Bridge Capital GP, Ltd. b OO N E9 0.00 23369824.00 0.00 23369824.00 23369824.00 Y 8.8 CO Y I-Bridge Healthcare Fund, L.P. b OO N E9 0.00 9216114.00 0.00 9216114.00 9216114.00 Y 3.5 PN Y I-Bridge Healthcare GP, L.P. b OO N E9 0.00 9216114.00 0.00 9216114.00 9216114.00 Y 3.5 PN Y I-Bridge Capital GP, Ltd. b OO N E9 0.00 9216114.00 0.00 9216114.00 9216114.00 Y 3.5 PN Y Wei Fu b OO N U0 0.00 30499709.00 0.00 30499709.00 30499709.00 Y 11.5 IN Ordinary Shares, par value $0.0001 per share (Including Ordinary Shares Underlying American Depository Shares) NovaBridge Biosciences SUITE 400, 2440 RESEARCH BLVD ROCKVILLE MD 20850 Explanatory Note: This statement constitutes Amendment No. 2 ("Amendment No. 2") to the Statement on Schedule 13D filed with the Securities and Exchange Commission (the "SEC") on February 5, 2025 (the "Original Schedule 13D") as amended by Amendment No. 1 filed on August 5, 2025 (the Original Schedule 13D as so amended, the "Schedule 13D"), jointly by (i) CBC Investment l-Mab Limited, a British Virgin Islands company ("CBC"), (ii) IBC Investment Seven Limited, a Hong Kong company ("IBC"), (iii) CBC SPVII Limited, a Hong Kong ("CBC SPVII"), (iv) C-Bridge II Investment Ten Limited, a British Virgin Islands company ("C-Bridge"), (v) Nova Aqua Limited, a British Virgin company ("Nova"), (vi) C-Bridge Healthcare Fund II, L.P., a Cayman Islands limited partnership ("C-Bridge Healthcare"), (vii) C-Bridge Healthcare Fund GP II, L.P., a Cayman Islands limited partnership ("C-Bridge Healthcare GP"), (viii) C-Bridge Capital GP, Ltd., a Cayman Islands company ("C-Bridge Capital"), (ix) l-Bridge Healthcare Fund, L.P., a Cayman Islands limited partnership ("I- Bridge"), (x) l-Bridge Healthcare GP, L.P., a Cayman Islands limited partnership ("l-Bridge GP"), (xi) I- Bridge Capital GP, Ltd., a Cayman Islands company ("l-Bridge Capital") and (xii) Wei Fu, a citizen of Singapore ("Mr. Fu" and collectively, the "Reporting Persons"). Except as amended hereby, the Schedule 13D remains in full force and effect. All capitalized terms contained but not otherwise defined herein shall have the meanings ascribed to such terms in the Schedule 13D. Responses to each item of the Schedule 13D, as amended by this Amendment No. 2, are incorporated by reference into the responses to each other item, as applicable. This Amendment No. 2 is filed by (i) CBC, (ii) IBC, (iii) CBC SPVII, (iv) C-Bridge, (v) Nova, (vi) C-Bridge Healthcare, (vii) C-Bridge Healthcare GP, (viii) C-Bridge Capital, (ix) l-Bridge, (x) l-Bridge GP, (xi) l-Bridge Capital, and (xii) Mr. Fu CBC Investment l-Mab Limited and C-Bridge II Investment Ten Limited are principally engaged in making investments and are controlled by C-Bridge Healthcare Fund II, L.P., which is principally engaged in making investments and whose general partner is C-Bridge Healthcare Fund GP II, L.P., and its general partner is C-Bridge Capital GP, Ltd. CBC SPVII Limited and IBC Investment Seven Limited are principally engaged in making investments and are controlled by I-Bridge Healthcare Fund, L.P., which is principally engaged in making investments, whose general partner is I-Bridge Healthcare GP, L.P., and its general partner is I-Bridge Capital GP, Ltd., which is indirectly controlled by C-Bridge Capital GP, Ltd. C-Bridge Healthcare Fund GP II, L.P., C-Bridge Capital GP, Ltd. and I-Bridge Healthcare GP, L.P. are principally engaged in being the general partner of their respective partnerships. Mr. Wei Fu may be deemed to control C-Bridge Capital GP, Ltd. and is principally engaged in making and managing investments. Nova Aqua Limited is held through a trust established by Mr. Wei Fu and is principally engaged in holding assets. Each of CBC, C-Bridge and Nova is a British Virgin Islands company. Each of IBC and CBC SPVII is a Hong Kong company. Each of C-Bridge Capital and I-Bridge Capital is a Cayman Islands company. Each of C-Bridge Healthcare, C-Bridge Healthcare GP, I-Bridge and I-Bridge GP is a Cayman Islands limited partnership. Mr. Fu is a citizen of Singapore. CBC is the record owner of 11,784,164 ordinary shares represented by 5,123,549 American Depositary Shares ("ADSs") (each ten (10) ADSs representing twenty-three (23) ordinary shares). CBC is controlled by C-Bridge Healthcare, C-Bridge Healthcare GP is the general partner of C-Bridge Healthcare, C-Bridge Capital is the general partner of C-Bridge Healthcare GP and Mr. Fu may be deemed to control C-Bridge Capital. IBC is the record owner of 3,641,544 ordinary shares represented by 1,583,284 ADSs. IBC is controlled by I-Bridge, I-Bridge GP is the general partner of I-Bridge, C-Bridge Capital is the general partner of I-Bridge GP and Mr. Fu may be deemed to control C-Bridge Capital. CBC SPVII is the record owner of 5,574,560 ordinary shares represented by 2,423,721 ADSs. CBC SPVII is controlled by I-Bridge, I-Bridge GP is the general partner of I-Bridge, C-Bridge Capital is the general partner of I-Bridge GP and Mr. Fu may be deemed to control C-Bridge Capital. C-Bridge is the record owner of 2,369,546 ordinary shares represented by 1,030,237 ADSs. C-Bridge is controlled by C-Bridge Healthcare, C-Bridge Healthcare GP is the general partner of C-Bridge Healthcare, C-Bridge Capital is the general partner of C-Bridge Healthcare GP and Mr. Fu may be deemed to control C-Bridge Capital. Nova is the record owner of 7,129,885 ordinary shares represented by 3,099,950 ADSs. The shares are held through a trust which was established by Mr. Fu (as the settlor) for the benefit of Mr. Wei Fu and his family. Each of CBC, IBC, CBC SPVII, C-Bridge, Nova, C-Bridge Healthcare, C-Bridge Healthcare GP, C-Bridge Capital, I-Bridge, I-Bridge GP, I-Bridge Capital and Mr. Fu may be deemed to beneficially own 4.4%, 1.4%, 2.1%, 0.9%, 2.7%, 5.3%, 5.3%, 8.8%, 3.5%, 3.5%, 3.5% and 11.5%, respectively, of the Issuer's outstanding ordinary shares, which percentages are calculated based on 265,169,373 ordinary shares outstanding following the completion of an underwritten offering, as described in the Issuers Current Report on Form 6-K, filed by the Issuer with Securities and Exchange Commission on December 18, 2025. CBC shares voting and dispositive power over 11,784,164 ordinary shares represented by 5,123,549 ADSs. IBC shares voting and dispositive power over 3,641,544 ordinary shares represented by 1,583,284 ADSs. CBC SPVII shares voting and dispositive power over 5,574,560 ordinary shares represented by 2,423,721 ADSs. C-Bridge shares voting and dispositive power over 2,369,546 ordinary shares represented by 1,030,237 ADSs. Nova shares voting and dispositive power over 7,129,885 ordinary shares represented by 3,099,950 ADSs. C-Bridge Healthcare shares voting and dispositive power over 14,153,710 ordinary shares represented by 6,153,786 ADSs. C-Bridge Healthcare GP shares voting and dispositive power over 14,153,710 ordinary shares represented by 6,153,786 ADSs. C-Bridge Capital shares voting and dispositive power over 23,369,824 ordinary shares represented by 10,160,793 ADSs. I-Bridge shares voting and dispositive power over 9,216,114 ordinary shares represented by 4,007,006 ADSs. I-Bridge GP shares voting and dispositive power over 9,216,114 ordinary shares represented by 4,007,006 ADSs. I-Bridge Capital shares voting and dispositive power over 9,216,114 ordinary shares represented by 4,007,006 ADSs. Mr. Fu shares voting and dispositive power over 30,499,709 ordinary shares represented by 13,239,003 ADSs. Schedule I sets forth the purchases of ADSs effected by Nova during the past 60 days and is incorporated by reference herein. All of the ADSs were purchased in open market transactions through a broker. Except as otherwise set forth herein, none of the Reporting Persons has effected any transactions in the Issuer's ordinary shares or ADSs during the past 60 days. 99.6 Schedule I, dated February 2, 2026. CBC Investment I-Mab Limited /s/ Wei Fu 02/03/2026 IBC Investment Seven Limited /s/ Wei Fu 02/03/2026 CBC SPVII LIMITED /s/ Wei Fu 02/03/2026 C-Bridge II Investment Ten Limited /s/ Wei Fu 02/03/2026 Nova Aqua Limited /s/ Wei Fu 02/03/2026 C-Bridge Healthcare Fund II, L.P. /s/ Wei Fu 02/03/2026 C-Bridge Healthcare Fund GP II, L.P. /s/ Wei Fu 02/03/2026 C-Bridge Capital GP, Ltd. /s/ Wei Fu 02/03/2026 I-Bridge Healthcare Fund, L.P. /s/ Wei fu 02/03/2026 I-Bridge Healthcare GP, L.P. /s/ Wei Fu 02/03/2026 I-Bridge Capital GP, Ltd. /s/ Wei Fu 02/03/2026 Wei Fu /s/ Wei Fu 02/03/2026