LeonaBio insider reports purchase of 3.15M shares

The warrant note and common-stock row report different resulting share counts, and the common-stock transaction’s stated price is unusable.

Rhea-AI Filing Summary

LeonaBio, Inc. (LONA) reported a common-stock purchase and a warrant disposition dated October 26, 2026. The common-stock transaction row records an indirect purchase of 3,149,470 shares, with 3,149,470 shares reported afterward; the row’s reported price is not usable. No Rule 10b5-1 plan is reported.

A separate row reports disposition of a warrant covering 5,502,402 common shares, with an exercise price of $0.0010 per share. Its footnotes attribute the warrant to Sermonix Pharmaceuticals, Inc., whose CEO is reporting person David J. Portman. The footnote says the securities are reported to reflect his voting control and that his personal indirect beneficial ownership does not exceed 10%. It says the warrant was partly exercised into 3,149,740 shares and the remaining rights assigned to Perceptive Xentogeny Venture Fund II, LP as a distribution-in-kind; Sermonix then held 3,149,740 shares.

Insider Trade Summary

Net Buyer: 8,651,872 shares

Net Buy 2 txns

Insider Portman David J.

Role 10% Owner

Bought 8,651,872 shs

Type	Security	Shares	Price	Value
Purchase	Warrant F1, F2, F3	5,502,402	$3,149.47	$17.33B
Purchase	Common Stock	3,149,470	$3,149.47 as filed	--

• Price shown as filed: $3,149.47 per share is far above the $4.76 close on Oct 26, 2026, so no transaction value is shown.

Holdings After Transaction: Warrant — 0 contracts (Indirect, See note); Common Stock — 3,149,470 shares (Indirect, See note)

Footnotes (3)

1. F1. The shares are held by Sermonix Pharmaceuticals, Inc. of which Dr. Portman is the Chief Executive Officer. This Form 4 is being filed to report Dr. Portman's voting control over such securities, but Dr. Portman's personal indirect beneficial ownership does not exceed 10% of the stock in the Issuer.
2. F2. The Warrant does not expire.
3. F3. The Warrant was held by Sermonix Pharmaceuticals, Inc. of which Dr. Portman is the Chief Executive Officer. The Warrant was exercised on October 26, 2026, in part, into 3,149,740 Common Shares of Issuer, and the balance of the Warrant was assigned to Perceptive Xentogeny Venture Fund II, LP as a distribution-in-kind pursuant to a plan of distribution to the Sermonix Pharmaceuticals equity holders. Following the partial exercise and the assignment of the remaining Warrant rights, Sermonix Pharmaceuticals holds 3,149,740 Common Shares of Issuer.

Key Figures

Common shares covered by warrant: 5,502,402 common shares Warrant exercise price: $0.0010 per share Common-stock purchase: 3,149,470 shares +3 more

6 metrics

Common shares covered by warrant 5,502,402 common shares Warrant disposition reported October 26, 2026

Warrant exercise price $0.0010 per share Warrant row

Common-stock purchase 3,149,470 shares Indirect transaction reported October 26, 2026

Common shares following transaction 3,149,470 shares Common-stock transaction row

Shares from partial warrant exercise 3,149,740 common shares Warrant footnote

Sermonix common shares after warrant actions 3,149,740 shares Warrant footnote

Key Terms

distribution-in-kind, voting control, personal indirect beneficial ownership, Warrant

4 terms

distribution-in-kind financial

"as a distribution-in-kind pursuant to a plan of distribution"

A distribution-in-kind is when a company or fund pays shareholders with assets—such as stock, bonds, or physical property—instead of cash. For investors it matters because the received items may be harder to sell, have different tax consequences, and can change the risk and value of their holdings, similar to being handed a slice of pie instead of money for your share of the bakery.

voting control regulatory

"report Dr. Portman's voting control over such securities"

personal indirect beneficial ownership regulatory

"personal indirect beneficial ownership does not exceed 10%"

Warrant financial

"The Warrant was exercised on October 26, 2026"

A warrant is a time-limited financial contract that gives its holder the right to buy a company's shares at a set price before a specified date, like a coupon that lets you purchase stock at a fixed discount for a limited time. It matters to investors because warrants offer leveraged exposure to a stock’s upside and can dilute existing shareholders if exercised, so they affect potential gains and the company’s outstanding share count.

FAQ

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

How many LONA shares were reported in the common-stock transaction?

The common-stock row reports an indirect purchase of 3,149,470 shares on October 26, 2026, with the same share count reported afterward. Its reported price is not usable, and no Rule 10b5-1 plan is reported.

What happened to the LONA warrant held by Sermonix Pharmaceuticals?

The footnote says it was exercised in part on October 26, 2026 into 3,149,740 common shares, and the remaining warrant rights were assigned to Perceptive Xentogeny Venture Fund II, LP as a distribution-in-kind.

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

Form 4 Insider Transactions: What Each Field Means →

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Available on EDGAR 10/28/2026 - 08:43 PM EDT Accepted by SEC EDGAR 10/28/2026 - 08:43 PM EDT Learn about SEC filing dates

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
Estimated average burden
hours per response:			0.5

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^*

Portman David J.

(Last) (First) (Middle)

250 E. BROAD ST., SUITE 250

(Street)

COLUMBUS OHIO 43215

(City) (State) (Zip)

UNITED STATES

(Country)

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

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

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
10/26/2026

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

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

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

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	10/26/2026	10/26/2026	P		3,149,470	A	$3,149.47	3,149,470	I	See note

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
Warrant(1)	$0.001	10/26/2026	10/26/2026	P			5,502,402	10/26/2026	(2)	Common Stock	5,502,402	$3,149.47	0	I	See note(3)

Explanation of Responses:

1. The shares are held by Sermonix Pharmaceuticals, Inc. of which Dr. Portman is the Chief Executive Officer. This Form 4 is being filed to report Dr. Portman's voting control over such securities, but Dr. Portman's personal indirect beneficial ownership does not exceed 10% of the stock in the Issuer.

2. The Warrant does not expire.

3. The Warrant was held by Sermonix Pharmaceuticals, Inc. of which Dr. Portman is the Chief Executive Officer. The Warrant was exercised on October 26, 2026, in part, into 3,149,740 Common Shares of Issuer, and the balance of the Warrant was assigned to Perceptive Xentogeny Venture Fund II, LP as a distribution-in-kind pursuant to a plan of distribution to the Sermonix Pharmaceuticals equity holders. Following the partial exercise and the assignment of the remaining Warrant rights, Sermonix Pharmaceuticals holds 3,149,740 Common Shares of Issuer.

	David J. Portman	10/28/2026
	** 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.
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.
* Form 4: SEC 1474 (03-26)