24,000-share stock unit grant to Syndax (SNDX) director Rizo

Rhea-AI Filing Summary

Syndax Pharmaceuticals director Aleksandra Rizo reported a grant of 24,000 shares of common stock on February 4, 2026. The award was made at a price of $0 per share and increased her beneficial ownership to 49,000 shares held directly.

The grant represents restricted stock units that vest one year from the grant date. The underlying shares will only be delivered, and therefore cannot be transferred or sold, until the earlier of a separation from service, death, disability, or a change in control.

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^*

Rizo Aleksandra

(Last) (First) (Middle)

C/O SYNDAX PHARMACEUTICALS, INC.

730 THIRD AVENUE, FLOOR 9

(Street)

NEW YORK NY 10017

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Syndax Pharmaceuticals Inc [ SNDX ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
02/04/2026

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	02/04/2026		A		24,000(1)	A	$0	49,000	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

Explanation of Responses:

1. Award of Restricted Stock Units that vests one year from the date of grant. The shares underlying such Restricted Stock Units will not be delivered to the Reporting Person and may not be transferred or sold until the earlier of a separation from service, death, disability or change in control.

	/s/ Michael A. Metzger, Attorney-in-Fact	02/06/2026
	** 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.

FAQ

What insider transaction did Syndax (SNDX) director Aleksandra Rizo report?

Aleksandra Rizo reported receiving 24,000 shares of Syndax common stock. The Form 4 shows an acquisition of 24,000 shares on February 4, 2026 at a price of $0 per share, increasing her directly held beneficial ownership to 49,000 shares.

How many Syndax (SNDX) shares does Aleksandra Rizo own after this Form 4?

After the reported transaction, Aleksandra Rizo beneficially owns 49,000 shares. The Form 4 shows a grant of 24,000 shares of common stock, bringing her total directly held position in Syndax Pharmaceuticals to 49,000 shares following the award.

What type of equity award did Syndax (SNDX) grant to director Aleksandra Rizo?

The award is in the form of restricted stock units. The footnote explains that 24,000 restricted stock units were granted, with the underlying shares subject to vesting and delivery conditions rather than being immediately transferable or freely tradable common stock.

When do Aleksandra Rizo’s Syndax (SNDX) restricted stock units vest?

The restricted stock units vest one year from the grant date. The footnote states that the 24,000 restricted stock units awarded to Aleksandra Rizo vest one year after February 4, 2026, which is the date of grant reported in the Form 4 filing.

When can the shares underlying Aleksandra Rizo’s SNDX restricted stock units be delivered or sold?

The underlying shares are deliverable only upon specific triggering events. They may not be delivered, transferred, or sold until the earlier of a separation from service, death, disability, change in control, or the one-year vesting schedule described for the restricted stock units.

Was there a purchase price for Aleksandra Rizo’s newly acquired Syndax (SNDX) shares?

The reported acquisition price per share was $0. The Form 4 states that the 24,000 shares of Syndax common stock associated with the restricted stock unit award were acquired at a transaction price of $0 per share on February 4, 2026.