Crescent Biopharma holder plans 16,775-share sale

Rule 144 notice for a CBIO executive details a planned 16,775-share sale, prior sales, and RSU-based share acquisition.

Rhea-AI Filing Summary

Crescent Biopharma, Inc. (CBIO) is the issuer for a Rule 144 notice filed for the account of Joshua T. Brumm covering proposed sales of its ordinary shares.

The notice reports a planned sale of 16,775 ordinary shares, acquired through restricted stock unit vesting from the issuer on September 17, 2026 as compensation for services. It also lists sales during the past three months of 42,305 ordinary shares on June 22, 2026 for $761,257.32 and 1,610 ordinary shares on September 16, 2026 for $28,815.62. Securities information shows 9,013 ordinary shares in a Morgan Stanley Smith Barney LLC Executive Financial Services account, with an associated value of $154,843.34 and a date of September 18, 2026.

Key Figures

Planned shares to be sold: 16,775 ordinary shares Sale on June 22, 2026: 42,305 ordinary shares; $761,257.32 Sale on September 16, 2026: 1,610 ordinary shares; $28,815.62 +1 more

4 metrics

Planned shares to be sold 16,775 ordinary shares Ordinary shares to be sold by Joshua T. Brumm under Rule 144

Sale on June 22, 2026 42,305 ordinary shares; $761,257.32 Ordinary shares sold by Joshua T. Brumm during the past three months

Sale on September 16, 2026 1,610 ordinary shares; $28,815.62 Additional ordinary share sale by Joshua T. Brumm during the past three months

Shares in brokerage account 9,013 ordinary shares; $154,843.34 Ordinary shares held in Morgan Stanley Smith Barney LLC Executive Financial Services account with date September 18, 2026

Key Terms

Rule 144, Restricted Stock Unit Vesting, Ordinary Shares, services rendered

4 terms

Rule 144 regulatory

"See the definition of "person" in paragraph (a) of Rule 144."

Rule 144 is a U.S. securities regulation that sets conditions under which restricted or insider-held shares can be legally resold to the public, such as required holding periods, availability of public information, limits on how much can be sold at once, and certain filing requirements. For investors it matters because it determines when previously locked-up shares can enter the market — like a release valve that can increase supply, affect share price, and signal insider intent.

Restricted Stock Unit Vesting financial

"Ordinary Shares | 09/17/2026 | Restricted Stock Unit Vesting | Issuer |"

Ordinary Shares financial

"Ordinary Shares | Morgan Stanley Smith Barney LLC Executive Financial Services"

Ordinary shares are a type of ownership stake in a company, giving shareholders a right to participate in the company’s profits and decision-making through voting. They are similar to owning a piece of a business, and their value can rise or fall based on the company's performance. Investors buy ordinary shares to potentially earn dividends and benefit from the company's growth over time.

services rendered financial

"16775 | 09/17/2026 | Services rendered"

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What Rule 144 sale of CBIO shares is being proposed in this notice?

The notice covers a proposed Rule 144 sale of 16,775 ordinary shares of Crescent Biopharma, Inc. These shares were acquired through restricted stock unit vesting from the issuer on September 17, 2026 in connection with services rendered.

Who is the selling security holder named in the CBIO Rule 144 filing?

The selling security holder is Joshua T. Brumm. The notice states that information is provided for the person for whose account the securities are to be sold, consistent with the definition of “person” in paragraph (a) of Rule 144.

What recent CBIO share sales by Joshua T. Brumm are disclosed?

The filing discloses sales of 42,305 ordinary shares on June 22, 2026 for $761,257.32 and 1,610 ordinary shares on September 16, 2026 for $28,815.62, all identified as ordinary shares of Crescent Biopharma, Inc.

How were the CBIO shares to be sold under Rule 144 acquired?

The 16,775 ordinary shares to be sold were acquired via Restricted Stock Unit Vesting from the issuer on September 17, 2026. The filing states the nature of payment as services rendered, indicating the shares were received as compensation.

What CBIO shares are held in the Morgan Stanley Smith Barney account?

Securities information lists 9,013 ordinary shares of Crescent Biopharma, Inc. in a Morgan Stanley Smith Barney LLC Executive Financial Services account, with a value of $154,843.34 and a related date of September 18, 2026, and indicates the shares trade on Nasdaq.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Available on EDGAR 09/17/2026 - 04:33 PM Accepted by SEC EDGAR 09/17/2026 - 04:33 PM Learn about SEC filing dates

Form 144 Filer Information	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 144 NOTICE OF PROPOSED SALE OF SECURITIES PURSUANT TO RULE 144 UNDER THE SECURITIES ACT OF 1933
FORM 144

144: Filer Information

Filer CIK	0001528826
Filer CCC	XXXXXXXX
Is this a LIVE or TEST Filing?	LIVE TEST
Submission Contact Information
Name
Phone
E-Mail Address

144: Issuer Information

Name of Issuer	Crescent Biopharma, Inc.
SEC File Number	001-36177
Address of Issuer	300 5th Ave Waltham MASSACHUSETTS 02451
Phone	6174305595
Name of Person for Whose Account the Securities are To Be Sold	Joshua T Brumm
See the definition of "person" in paragraph (a) of Rule 144. Information is to be given not only as to the person for whose account the securities are to be sold but also as to all other persons included in that definition. In addition, information shall be given as to sales by all persons whose sales are required by paragraph (e) of Rule 144 to be aggregated with sales for the account of the person filing this notice.
Relationship to Issuer	Officer
Relationship to Issuer	Director

144: Securities Information

Title of the Class of Securities To Be Sold	Name and Address of the Broker	Number of Shares or Other Units To Be Sold	Aggregate Market Value	Number of Shares or Other Units Outstanding	Approximate Date of Sale	Name the Securities Exchange
Ordinary Shares	Morgan Stanley Smith Barney LLC Executive Financial Services 1 New York Plaza 8th Floor New York NY 10004	9013	154843.34	37143940	09/18/2026	Nasdaq

Furnish the following information with respect to the acquisition of the securities to be sold and with respect to the payment of all or any part of the purchase price or other consideration therefor:

144: Securities To Be Sold

Title of the Class	Date you Acquired	Nature of Acquisition Transaction	Name of Person from Whom Acquired	Is this a Gift?	Date Donor Acquired	Amount of Securities Acquired	Date of Payment	Nature of Payment *
Ordinary Shares	09/17/2026	Restricted Stock Unit Vesting	Issuer			16775	09/17/2026	Services rendered

* If the securities were purchased and full payment therefor was not made in cash at the time of purchase, explain in the table or in a note thereto the nature of the consideration given. If the consideration consisted of any note or other obligation, or if payment was made in installments describe the arrangement and state when the note or other obligation was discharged in full or the last installment paid.

Furnish the following information as to all securities of the issuer sold during the past 3 months by the person for whose account the securities are to be sold.

144: Securities Sold During The Past 3 Months

Name and Address of Seller	Title of Securities Sold	Date of Sale	Amount of Securities Sold	Gross Proceeds
Joshua T Brumm 300 5th Ave Waltham MA 02451	Ordinary Shares	06/22/2026	42305	761257.32
Joshua T Brumm 300 5th Ave Waltham MA 02451	Ordinary Shares	09/16/2026	1610	28815.62

144: Remarks and Signature

Remarks
Date of Notice	09/17/2026
Date of Plan Adoption or Giving of Instruction, If Relying on Rule 10b5-1	02/28/2026
ATTENTION:
The person for whose account the securities to which this notice relates are to be sold hereby represents by signing this notice that he does not know any material adverse information in regard to the current and prospective operations of the Issuer of the securities to be sold which has not been publicly disclosed. If such person has adopted a written trading plan or given trading instructions to satisfy Rule 10b5-1 under the Exchange Act, by signing the form and indicating the date that the plan was adopted or the instruction given, that person makes such representation as of the plan adoption or instruction date.
Signature	/s/ Barbara Bispham Hale, as Attorney-in-Fact for Joshua T Brumm
ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)