Phathom Pharmaceuticals (PHAT) CEO reports 90,000-share PSU exercise and tax share surrender

Rhea-AI Filing Summary

Phathom Pharmaceuticals reported an insider equity transaction by its President and CEO and director, Steven L. Basta. On 11/28/2025, 90,000 shares of common stock were acquired through the exercise of performance stock units at an exercise price of $0, increasing his directly held common stock to 131,625 shares before tax settlements.

On the same date, 48,375 shares of common stock were surrendered at a price of $15.62 to cover tax withholding obligations, leaving 83,250 common shares held directly after the transactions. The derivative table shows performance share units with 90,000 shares underlying this exercise and 180,000 derivative securities remaining beneficially owned. The filing explains that 360,000 performance stock units were granted on April 3, 2025, with vesting tied to stock price hurdles over four years and continued service.

Insider Trade Summary

90,000 shares exercised/converted

Mixed 3 txns

Insider Basta Steven L

Role President and CEO

Type	Security	Shares	Price	Value
Exercise	Performance Shares	90,000	$0.00	--
Exercise	Common Stock	90,000	$0.00	--
Tax Withholding	Common Stock	48,375	$15.62	$756K

Holdings After Transaction: Performance Shares — 180,000 shares (Direct); Common Stock — 131,625 shares (Direct)

Footnotes (1)

1. Represents shares underlying the performance stock units that were surrendered by the reporting person to the Issuer in satisfaction of the Issuer's tax withholding obligation. Each performance stock unit represents a contingent right to receive one share of common stock of the Issuer. On April 3, 2025, the reporting person was granted 360,000 performance stock units, of which 90,000 vested on September 25, 2025 and an additional 90,000 vested on November 28, 2025, in each case due to the achievement of the applicable stock price hurdle. The remaining performance stock units will vest based on the achievement of stock price hurdles over a period of four years following the grant date, subject to the reporting person's continued service through the date each such stock price hurdle is achieved.

Form 4 Insider Transactions: What Each Field Means →

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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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^*

Basta Steven L

(Last) (First) (Middle)

C/O PHATHOM PHARMACEUTICALS, INC.

100 CAMPUS DRIVE, SUITE 102

(Street)

FLORHAM PARK 07932

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Phathom Pharmaceuticals, Inc. [ PHAT ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
11/28/2025

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	11/28/2025		M		90,000	A	$0	131,625	D
Common Stock	11/28/2025		F(1)		48,375	D	$15.62	83,250	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
Performance Shares	$0(2)	11/28/2025		M			90,000	(3)	(3)	Common Stock	90,000	$0	180,000	D

Explanation of Responses:

1. Represents shares underlying the performance stock units that were surrendered by the reporting person to the Issuer in satisfaction of the Issuer's tax withholding obligation.

2. Each performance stock unit represents a contingent right to receive one share of common stock of the Issuer.

3. On April 3, 2025, the reporting person was granted 360,000 performance stock units, of which 90,000 vested on September 25, 2025 and an additional 90,000 vested on November 28, 2025, in each case due to the achievement of the applicable stock price hurdle. The remaining performance stock units will vest based on the achievement of stock price hurdles over a period of four years following the grant date, subject to the reporting person's continued service through the date each such stock price hurdle is achieved.

	/s/ Steven L. Basta	12/02/2025
	** Signature of Reporting Person	Date
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