Crescent Biopharma (CBIO) insider awarded RSUs and 72,185 stock options

Rhea-AI Filing Summary

Crescent Biopharma, Inc. reported an equity compensation grant to an executive officer. On December 15, 2025, the reporting person received 12,422 Ordinary Shares and an additional 6,000 Ordinary Shares as Restricted Stock Units, bringing their beneficial ownership to 18,422 Ordinary Shares. The RSUs vest in approximately equal three‑month installments over four years from December 15, 2025, contingent on continued service.

The officer was also granted a stock option for 72,185 Ordinary Shares at an exercise price of $13.21 per share, exercisable until December 15, 2035. This option vests as to 1/48th of the grant on each monthly anniversary of December 15, 2025, as long as the officer remains employed by or provides services to Crescent Biopharma or its subsidiaries.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Bispham Barbara Harlin

(Last) (First) (Middle)

C/O CRESCENT BIOPHARMA, INC.

300 FIFTH AVENUE

(Street)

WALTHAM MA 02451

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
CRESCENT BIOPHARMA, INC. [ CBIO ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	See Remarks

3. Date of Earliest Transaction (Month/Day/Year)
12/15/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Ordinary Shares	12/15/2025		A		12,422	A	(1)	12,422	D
Ordinary Shares	12/15/2025		A		6,000	A	(1)	18,422	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Stock Option (Right to Buy)	$13.21	12/15/2025		A		72,185		(2)	12/15/2035	Ordinary Shares	72,185	$0	72,185	D

Explanation of Responses:

1. Represents an award of Restricted Stock Units ("RSUs"). Each RSU represents a contingent right to receive one share of the Issuer's Ordinary Shares. The RSUs shall vest in approximately equal three-month installments through the four-year anniversary of December 15, 2025, subject to the Reporting Person remaining continuously employed by or providing services to the Issuer or its subsidiaries from December 15, 2025 through each such vesting date.

2. This Option represents a right to purchase shares of the Issuer's Ordinary Shares and vests with respect to 1/48th of the Option on each monthly anniversary of December 15, 2025, subject to the Reporting Person remaining continuously employed by or providing services to the Issuer or its subsidiaries from December 15, 2025 through each such vesting date.

Remarks:

General Counsel and Corporate Secretary.

	/s/ Barbara Bispham	12/17/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What insider equity awards did Crescent Biopharma (CBIO) report?

Crescent Biopharma reported that an officer received 18,422 Ordinary Shares via Restricted Stock Units and a stock option for 72,185 Ordinary Shares on December 15, 2025.

Who is the reporting person in this Crescent Biopharma (CBIO) Form 4 filing?

The reporting person is an officer of Crescent Biopharma serving as General Counsel and Corporate Secretary, as noted in the remarks.

How do the Crescent Biopharma (CBIO) RSU awards vest?

The Restricted Stock Units vest in approximately equal three‑month installments through the four‑year anniversary of December 15, 2025, subject to continued service.

What are the key terms of the Crescent Biopharma (CBIO) stock option grant?

The stock option covers 72,185 Ordinary Shares at an exercise price of $13.21 per share, with an expiration date of December 15, 2035.

How does the Crescent Biopharma (CBIO) stock option vest over time?

The option vests as to 1/48th of the grant on each monthly anniversary of December 15, 2025, conditioned on the officer’s continued service.

What is the officer’s Ordinary Share ownership after these Crescent Biopharma (CBIO) transactions?

Following the reported transactions, the officer beneficially owns 18,422 Ordinary Shares of Crescent Biopharma.