SEC FORM 4

Please wait

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^*

SEIDENBERG BETH C

(Last)

(First)

(Middle)

C/O LATIGO BIOTHERAPEUTICS, INC.

1300 RANCHO CONEJO BLVD., SUITE 305

(Street)

THOUSAND OAKS

91320

(City)

(State)

(Zip)

2. Issuer Name and Ticker or Trading Symbol
Latigo Biotherapeutics, Inc. [ LTGO ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
08/10/2026

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)
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Stock	08/10/2026		C		938,979	A	⁽¹⁾	1,368,532	I	See footnote⁽²⁾
Common Stock	08/10/2026		C		3,547,842	A	⁽¹⁾	4,916,374	I	See footnote⁽²⁾
Common Stock	08/10/2026		C		1,027,635	A	⁽¹⁾	5,944,009	I	See footnote⁽²⁾
Common Stock	08/10/2026		C		3,464,072	A	⁽¹⁾	3,510,927	I	See footnote⁽³⁾
Common Stock	08/10/2026		C		1,484,401	A	⁽¹⁾	4,995,328	I	See footnote⁽³⁾
Common Stock	08/10/2026		C		165,519	A	⁽⁴⁾	5,160,847	I	See footnote⁽³⁾
Common Stock	08/10/2026		C		2,066,857	A	⁽¹⁾	2,094,813	I	See footnote⁽⁵⁾

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)
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)	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)		10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
Series Seed Convertible Stock	⁽¹⁾	08/10/2026		C			938,979	⁽¹⁾	⁽¹⁾	Common Stock	938,979	⁽¹⁾	0	I	See footnote⁽²⁾
Series A Convertible Preferred Stock	⁽¹⁾	08/10/2026		C			3,547,842	⁽¹⁾	⁽¹⁾	Common Stock	3,547,842	⁽¹⁾	0	I	See footnote⁽²⁾
Series A-2 Convertible Preferred Stock	⁽¹⁾	08/10/2026		C			1,027,635	⁽¹⁾	⁽¹⁾	Common Stock	1,027,635	⁽¹⁾	0	I	See footnote⁽²⁾
Series A-2 Convertible Preferred Stock	⁽¹⁾	08/10/2026		C			3,464,072	⁽¹⁾	⁽¹⁾	Common Stock	3,464,072	⁽¹⁾	0	I	See footnote⁽³⁾
Series B Convertible Preferred Stock	⁽¹⁾	08/10/2026		C			1,484,401	⁽¹⁾	⁽¹⁾	Common Stock	1,484,401	⁽¹⁾	0	I	See footnote⁽³⁾
Series A-2 Convertible Preferred Stock	⁽¹⁾	08/10/2026		C			2,066,857	⁽¹⁾	⁽¹⁾	Common Stock	2,066,857	⁽¹⁾	0	I	See footnote⁽⁵⁾
Convertible Promissory Note	⁽⁴⁾	08/10/2026		C			165,519	⁽⁴⁾	⁽⁴⁾	Common Stock	165,519	⁽⁴⁾	0	I	See footnote⁽³⁾

Explanation of Responses:

1. Each share of Series Seed Convertible Preferred Stock, Series A Convertible Preferred Stock, Series A-2 Convertible Preferred Stock and Series B Convertible Preferred Stock (collectively, the "Preferred Stock") converted automatically into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. Share numbers give effect to such conversion. The Preferred Stock had no expiration date.

2. Shares held directly by Westlake BioPartners Fund I, L.P. (Fund I). The general partner of Fund I is Westlake BioPartners GP I, LLC (GP I). GP I may be deemed to share voting and dispositive power with regard to the shares held directly by Fund I. The Reporting Person is the sole managing director of GP I and has voting and dispositive power over the shares held by Fund I. The Reporting Person disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of her pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of any of the reported shares for purposes of Section 16 or any other purpose.

3. Shares held directly by Westlake BioPartners Fund II, L.P. (Fund II). The general partner of Fund II is Westlake BioPartners GP II, LLC (GP II). GP II may be deemed to share voting and dispositive power with regard to the shares held directly by Fund II. The Reporting Person is the sole managing director of GP II and has voting and dispositive power over the shares held by Fund II. The Reporting Person disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of her pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of any of the reported shares for purposes of Section 16 or any other purpose.

4. Reflects a convertible note that is convertible into shares of Common Stock of the Issuer. The convertible note has a maturity date of June 17, 2027. The principal amount of the convertible note together with any accrued but unpaid interest automatically converted into shares of Common Stock of the Issuer upon the closing of the Issuer's initial public offering at a conversion price equal to the initial public offering price of the Issuer's common stock.

5. Shares held directly by Westlake BioPartners Opportunity Fund I, L.P. (Opportunity Fund). The general partner of Opportunity Fund is Westlake BioPartners Opportunity GP I, LLC (Opportunity GP). Opportunity GP may be deemed to share voting and dispositive power with regard to the shares held directly by Opportunity Fund. The Reporting Person is the sole managing director of Opportunity GP and has voting and dispositive power over the shares held by Opportunity Fund. The Reporting Person disclaims Section 16 beneficial ownership of the shares reported herein except to the extent of her pecuniary interest therein, if any, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of any of the reported shares for purposes of Section 16 or any other purpose.

	/s/ Sabrina Nieder, Attorney-in-Fact	08/10/2026
	** 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.