AnaptysBio (NASDAQ: ANAB) legal chief reports option exercises and stock sales

Rhea-AI Filing Summary

AnaptysBio’s chief legal officer reported option exercises and share sales. On December 16–18, 2025, the officer exercised employee stock options to buy common stock at $14.02 and $20.16 per share, then sold portions of the resulting shares in several trades.

Sales were made under a pre-arranged Rule 10b5-1 trading plan, with weighted average sale prices including $44.6756, $45.2369 and $46.00 per share. After these transactions, the officer directly owned 8,947 shares of common stock and held fully vested options covering 53,000 shares, plus additional options to purchase up to 414,810 shares that vest according to their terms.

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).

X

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^*

LOUMEAU ERIC J

(Last) (First) (Middle)

C/O ANAPTYSBIO, INC.

10770 WATERIDGE CIRCLE, SUITE 210

(Street)

SAN DIEGO CA 92121

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
ANAPTYSBIO, INC [ ANAB ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
12/16/2025

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	12/16/2025		M		5,000	A	$14.02	14,088	D
Common Stock	12/16/2025		M		7,500	A	$20.16	21,588	D
Common Stock	12/16/2025		S(1)		8,305	D	$44.6756(2)	13,283	D
Common Stock	12/16/2025		S(1)		4,195	D	$45.2369(3)	9,088	D
Common Stock	12/17/2025		M		10,000	A	$14.02	19,088	D
Common Stock	12/17/2025		S(1)		10,000	D	$46	9,088	D
Common Stock	12/18/2025		S(1)		141	D	$46.99	8,947	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
Employee Stock Option (right to buy)	$14.02	12/16/2025		M			5,000	(4)	12/05/2029	Common Stock	5,000	$0	63,000	D
Employee Stock Option (right to buy)	$20.16	12/16/2025		M			7,500	(4)	07/12/2030	Common Stock	7,500	$0	0	D
Employee Stock Option (right to buy)	$14.02	12/17/2025		M			10,000	(4)	12/05/2029	Common Stock	10,000	$0	53,000(5)	D

Explanation of Responses:

1. The transactions reported on this Form 4 were effected pursuant to a 10b5-1 trading plan adopted by the reporting person dated April 11, 2025.

2. The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $44.12 to $45.11 per share, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

3. The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $45.13 to $45.34 per share, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

4. The stock option is fully vested.

5. In addition to the options to purchase a total of 53,000 shares of common stock as set forth in Table II, the Reporting Person also holds additional options to purchase up to an aggregate of 414,810 shares of common stock, which options vest according to their terms.

	/s/ Eric Loumeau	12/18/2025
	** 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 insider transaction did ANAPTYSBIO (ANAB) disclose in this Form 4?

The filing shows the chief legal officer exercised employee stock options to acquire common stock at $14.02 and $20.16 per share, then sold portions of those shares in multiple transactions between December 16 and 18, 2025.

Who is the reporting person in the ANAB Form 4 and what is their role?

The reporting person is Eric Loumeau, who serves as Chief Legal Officer of AnaptysBio, Inc., as indicated in the relationship and signature sections.

At what prices were ANAPTYSBIO (ANAB) shares sold by the insider?

The shares were sold at weighted average prices including $44.6756, $45.2369, $46.00 and $46.99 per share. Footnotes explain that these prices reflect multiple trades within narrower price ranges.

Were the ANAB insider sales made under a Rule 10b5-1 trading plan?

Yes. The explanation of responses states that the transactions were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on April 11, 2025.

How many ANAPTYSBIO shares does the insider own after these transactions?

Following the reported transactions, the chief legal officer directly owned 8,947 shares of AnaptysBio common stock, as shown in the post-transaction ownership column of Table I.

What stock options does the ANAB insider hold after these transactions?

After the reported option exercises, the insider held fully vested options to purchase 53,000 shares of common stock, and also held additional options to purchase up to an aggregate of 414,810 shares, which vest according to their terms.

What types of securities are covered in this ANAPTYSBIO (ANAB) Form 4?

The filing covers common stock transactions in Table I and employee stock options (rights to buy common stock) in Table II, including their exercise prices, dates exercisable, and expiration dates.