Mark James Litton - 03 Mar 2026 Form 4 Insider Report for LeonaBio, Inc. (LONA)

Role: PRESIDENT and CEO, Director
Signature: /s/ Mark Worthington, Attorney-in-Fact on behalf of Mark James Litton
Issuer symbol: LONA
Transactions as of: 03 Mar 2026
Net transactions value: -$27,688
Form type: 4
Filing time: 05 Mar 2026, 19:14:48 UTC
Previous filing: 05 Jan 2026
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Litton Mark James	PRESIDENT and CEO, Director	C/O LEONABIO, INC., 18706 NORTH CREEK PARKWAY, SUITE 104, BOTHELL	/s/ Mark Worthington, Attorney-in-Fact on behalf of Mark James Litton	05 Mar 2026	0001604834

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	LONA	Common Stock	Options Exercise		+22,254	+55%	$0.000000^*	63,082	03 Mar 2026	Direct
transaction	LONA	Common Stock	Sale	$27,688	-5,156	-8.2%	$5.37	57,926	04 Mar 2026	Direct	F1, F2
holding	LONA	Common Stock						656	03 Mar 2026	By Irrevocable Trust of OSL	F3
holding	LONA	Common Stock						656	03 Mar 2026	By Irrevocable Trust of SWL	F4
holding	LONA	Common Stock						656	03 Mar 2026	By Irrevocable Trust of WGL	F5

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	LONA	Restricted Stock Units	Options Exercise		-22,254	-100%	$0.000000^*	0	03 Mar 2026	Common Stock	22,254		Direct	F6, F7

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	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.
F2	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.
F3	Reflects Common Stock held by Irrevocable Trust of OSL held for the benefit of Dr. Litton's children.
F4	Reflects Common Stock held by Irrevocable Trust of SWL held for the benefit of Dr. Litton's children.
F5	Reflects Common Stock held by Irrevocable Trust of WGL held for the benefit of Dr. Litton's children.
F6	Each RSU represents a contingent right to receive one (1) share of Issuer's common stock.
F7	On March 3, 2025, the reporting person was granted 22,254 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.