Insider Trading Arrangements	3 Months Ended
	Mar. 31, 2026
Trading Arrangements, by Individual
Material Terms of Trading Arrangement	On February 25, 2026, each of (i) Joshua Brumm, our Chief Executive Officer and member of the Company’s Board of Directors, (ii) Jonathan McNeill, our Chief Operating Officer and President, (iii) Ellie Im, our Chief Medical Officer, (iv) Jan Pinkas, our Chief Scientific Officer, (v) Richard Scalzo, our Chief Financial Officer, (vi) Ryan Lynch, our Treasurer, Senior Vice President of Finance and Chief Accounting Officer, and (vii) Barbara Bispham Hale, our General Counsel and Corporate Secretary, adopted a Rule 10b5-1 trading arrangement intended to satisfy the affirmative defense of Rule 10b5-1(c) authorizing the pre-arranged sale of ordinary shares in order to satisfy tax withholding obligations of the Company that arise in connection with the vesting of any restricted stock units and/or performance stock units granted to them under the Crescent Biopharma, Inc. 2025 Stock Incentive Plan, the Crescent Biopharma, Inc. 2025 Employment Inducement Incentive Award Plan and the Crescent Biopharma, Inc. 2024 Equity Incentive Plan, as amended, including under any successor plan and the related issuance of ordinary shares (each, a “Sell-to-Cover 10b5-1 Instruction”). The number of ordinary shares to be sold to satisfy the Company’s tax withholding obligations under each Sell-to-Cover 10b5-1 Instruction is not currently determinable. Each person’s Sell-to-Cover 10b5-1 Instruction will remain in effect so long as taxes are required to be paid upon the vesting or settlement of restricted stock units or performance stock units awarded or to be awarded to such person, unless such person’s instruction letter is earlier terminated.
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false
Joshua Brumm [Member]
Trading Arrangements, by Individual
Name	Joshua Brumm
Title	Chief Executive Officer and member of the Company’s Board of Directors
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	February 25, 2026
Jonathan McNeill [Member]
Trading Arrangements, by Individual
Name	Jonathan McNeill
Title	Chief Operating Officer and President
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	February 25, 2026
Ellie Im [Member]
Trading Arrangements, by Individual
Name	Ellie Im
Title	Chief Medical Officer
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	February 25, 2026
Jan Pinkas [Member]
Trading Arrangements, by Individual
Name	Jan Pinkas
Title	Chief Scientific Officer
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	February 25, 2026
Richard Scalzo [Member]
Trading Arrangements, by Individual
Name	Richard Scalzo
Title	Chief Financial Officer
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	February 25, 2026
Ryan Lynch [Member]
Trading Arrangements, by Individual
Name	Ryan Lynch
Title	Treasurer, Senior Vice President of Finance and Chief Accounting Officer
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	February 25, 2026
Barbara Bispham Hale [Member]
Trading Arrangements, by Individual
Name	Barbara Bispham Hale
Title	General Counsel and Corporate Secretary
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	February 25, 2026