LeonaBio (LONA) CMO covers RSU tax bill with share sale

Rhea-AI Filing Summary

LeonaBio, Inc.’s chief medical officer Javier San Martin reported equity compensation activity and a related tax sale. On March 3, 2026, 7,418 restricted stock units (RSUs) fully vested and were converted into 7,418 shares of common stock at a stated price of $0.00 per share.

On March 4, 2026, 1,720 shares of common stock were sold in open-market transactions at a weighted-average price of $5.37 per share, solely to cover tax withholding obligations under LeonaBio’s mandatory “sell to cover” policies, and not as a discretionary sale. After these transactions, Javier San Martin directly owned 15,887 shares of LeonaBio common stock.

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

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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^*

San Martin Javier

(Last) (First) (Middle)

C/O LEONABIO, INC.

18706 NORTH CREEK PARKWAY, SUITE 104

(Street)

BOTHELL WA 98011

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
LeonaBio, Inc. [ LONA ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
03/03/2026

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
Common Stock	03/03/2026		M		7,418	A	$0	17,607	D
Common Stock	03/04/2026		S(1)		1,720	D	$5.37(2)	15,887	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
Restricted Stock Units	(3)	03/03/2026		M			7,418	(4)	(4)	Common Stock	7,418	$0	0	D

Explanation of Responses:

1. Represents shares of common stock sold to cover tax withholding and remittance obligations in connection with the vesting of restricted stock units ("RSU") pursuant to mandatory "sell to cover" policies maintained by the Issuer and provisions contained in the reporting person's applicable RSU agreement, and does not represent a discretionary sale by the reporting person. No additional shares of common stock were sold by the reporting person.

2. The "Amount" and "Price" reported in this Column 4 reflect the aggregate number and weighted-average price, respectively, of shares sold. These shares were sold in multiple transactions at prices ranging from $5.03 to $5.70, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the SEC staff, upon request, full information regarding the number of shares sold at each separate price within the range set forth herein.

3. Each RSU represents a contingent right to receive one (1) share of Issuer's common stock.

4. On March 3, 2025, the reporting person was granted 7,418 RSUs (as adjusted for the 10-for-1 reverse stock split completed on September 17, 2025). 100% of the RSUs vested on the one (1) year anniversary of the grant date.

	/s/ Mark Worthington, Attorney-in-Fact on behalf of Javier San Martin	03/05/2026
	** 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 insider transactions did LeonaBio (LONA) report for its CMO?

LeonaBio’s chief medical officer Javier San Martin reported RSU vesting and a related tax sale. 7,418 restricted stock units converted into common shares, and 1,720 shares were sold in the market solely to cover tax withholding obligations under mandatory sell-to-cover policies.

How many LeonaBio shares did the CMO acquire through RSU vesting?

Javier San Martin acquired 7,418 shares of LeonaBio common stock through the vesting and conversion of 7,418 restricted stock units. Each RSU represents the right to receive one common share, and 100% of this grant vested on the one-year anniversary of the grant date.

How many LeonaBio shares did the CMO sell, and at what price?

The CMO sold 1,720 shares of LeonaBio common stock in open-market transactions at a weighted-average price of $5.37 per share. The sales occurred in multiple trades between $5.03 and $5.70 per share, according to the reported transaction range.

Why did the LeonaBio CMO sell shares after the RSUs vested?

The 1,720 shares were sold solely to cover tax withholding and remittance obligations triggered by RSU vesting. The sales followed LeonaBio’s mandatory “sell to cover” policies and the RSU agreement terms, and were not discretionary sales by the reporting person.

How many LeonaBio shares does the CMO own after these transactions?

Following the RSU conversion and the tax-related share sale, Javier San Martin directly owned 15,887 shares of LeonaBio common stock. This post-transaction holding reflects the newly issued shares from vested RSUs minus the shares sold to satisfy tax withholding obligations.