Form 4: RA Capital Entities Increase MLYS Stake with $25.50 Purchase

Rhea-AI Filing Summary

RA Capital entities reported an acquisition of Mineralys Therapeutics (MLYS) common stock on 09/04/2025. The filing shows a purchase of 1,176,470 shares at $25.50 per share. After the transaction, the reporting persons disclosed 5,456,521 shares beneficially owned (indirect) and an additional line showing 1,867,229 shares beneficially owned (indirect), with holdings held directly by RA Capital Healthcare Fund, L.P. and Nexus Fund III, L.P. The filing identifies RA Capital Management, L.P. as adviser and names Dr. Peter Kolchinsky and Rajeev Shah among reporting individuals; a partner of the adviser, Dr. Derek DiRocco, serves on the issuer's board. The form is signed by the reporting persons on 09/08/2025.

Positive

• Reported purchase of 1,176,470 shares at $25.50, showing an increase in ownership disclosed on Form 4
• Clear disclosures of fund ownership and adviser relationships, including footnotes explaining direct holdings by RA Capital Healthcare Fund and Nexus Fund III

Negative

• None.

Insights

Securities Analyst

TL;DR: RA Capital-related entities increased their stake in MLYS via a 1,176,470-share purchase at $25.50, signaling continued investor involvement.

The transaction is a straightforward disclosed purchase by affiliated investment vehicles and individuals tied to RA Capital. Reported beneficial ownership is held indirectly through RA Capital Healthcare Fund, L.P. and Nexus Fund III, L.P., with the Adviser and its managing members disclaiming beneficial ownership except for pecuniary interests as stated. The filing also notes an adviser partner on the issuer's board, which is relevant for governance transparency. Impact on valuation or control is not quantified in the filing.

Corporate Governance Expert

TL;DR: Disclosure clearly identifies relationships and indirect holdings; signatures and disclaimers provide standard governance transparency.

The Form 4 includes required footnote disclosures explaining direct holdings by funds and the advisory relationship, plus customary disclaimers of beneficial ownership except to the extent of pecuniary interest. The filing names individuals and affiliates and includes attestations by signatures dated 09/08/2025. The inclusion of an adviser partner on the issuer's board is disclosed, which addresses potential related-party considerations. The filing does not state any grants, dispositions, or derivative positions.

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

OMB Number:			3235-0287
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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^*

RA CAPITAL MANAGEMENT, L.P.

(Last) (First) (Middle)

200 BERKELEY STREET, 18TH FLOOR

(Street)

BOSTON MA 02116

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Mineralys Therapeutics, Inc. [ MLYS ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
09/04/2025

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

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

	Form filed by One Reporting Person
X	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
Common Stock	09/04/2025		P		1,176,470	A	$25.5	5,456,521	I	See footnotes(1)(2)
Common Stock								1,867,229	I	See footnotes(2)(3)

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

1. Name and Address of Reporting Person^*

RA CAPITAL MANAGEMENT, L.P.

(Last) (First) (Middle)

200 BERKELEY STREET, 18TH FLOOR

(Street)

BOSTON MA 02116

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

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

1. Name and Address of Reporting Person^*

RA Capital Healthcare Fund LP

(Last) (First) (Middle)

200 BERKELEY STREET, 18TH FLOOR

(Street)

BOSTON MA 02116

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

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

1. Name and Address of Reporting Person^*

RA Capital Nexus Fund III, L.P.

(Last) (First) (Middle)

200 BERKELEY STREET, 18TH FLOOR

(Street)

BOSTON MA 02116

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

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

1. Name and Address of Reporting Person^*

Kolchinsky Peter

(Last) (First) (Middle)

C/O RA CAPITAL MANAGEMENT, L.P.

200 BERKELEY STREET, 18TH FLOOR

(Street)

BOSTON MA 02116

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

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

1. Name and Address of Reporting Person^*

Shah Rajeev M.

(Last) (First) (Middle)

C/O RA CAPITAL MANAGEMENT, L.P.

200 BERKELEY STREET, 18TH FLOOR

(Street)

BOSTON MA 02116

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

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

Explanation of Responses:

1. Held directly by the RA Capital Healthcare Fund, L.P. (the "Fund").

2. RA Capital Management, L.P. (the "Adviser") is the investment manager for the Fund and RA Capital Nexus Fund III, L.P. (the "Nexus Fund III"). The general partner of the Adviser is RA Capital Management GP, LLC (the "Adviser GP"), of which Dr. Peter Kolchinsky and Mr. Rajeev Shah are the managing members. The Adviser, the Adviser GP, the Fund, the Nexus Fund III, Dr. Kolchinsky, and Mr. Shah disclaim beneficial ownership of any of the reported securities, except to the extent of their pecuniary interest therein.

3. Held directly by Nexus Fund III.

Remarks:

Dr. Derek DiRocco, a Partner of the Adviser, serves on the Issuer's board of directors.

	/s/ Peter Kolchinsky, Manager of RA Capital Management, L.P.	09/08/2025
	/s/ Peter Kolchinsky, Manager of RA Capital Healthcare Fund GP, LLC the General Partner of RA Capital Healthcare Fund, L.P.	09/08/2025
	/s/ Peter Kolchinsky, Manager of RA Capital Nexus Fund III GP, LLC the General Partner of RA Capital Nexus Fund III, L.P.	09/08/2025
	/s/ Peter Kolchinsky, individually	09/08/2025
	/s/ Rajeev Shah, individually	09/08/2025
	** 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.
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FAQ

What transaction did RA Capital report in the MLYS Form 4?

The filing reports a purchase of 1,176,470 common shares of Mineralys Therapeutics on 09/04/2025 at a price of $25.50 per share.

How many MLYS shares are reported as beneficially owned after the transaction?

The filing shows 5,456,521 shares beneficially owned (indirect) on one line and 1,867,229 shares beneficially owned (indirect) on another line, as stated in the form.

Which RA Capital entities are listed as reporting persons on the Form 4 for MLYS?

The reporting persons include RA Capital Management, L.P., RA Capital Healthcare Fund, L.P., RA Capital Nexus Fund III, L.P., and individuals Peter Kolchinsky and Rajeev Shah.

Does the Form 4 disclose any director relationship between RA Capital and Mineralys Therapeutics (MLYS)?

Yes. The filing indicates that a partner of the adviser, Dr. Derek DiRocco, serves on the issuer's board of directors.

When was the Form 4 signed by the reporting persons?

The signatures on the Form 4 are dated 09/08/2025.