Ultragenyx (RARE) CMO reports stock award and sale of common shares

Rhea-AI Filing Summary

Ultragenyx Pharmaceutical EVP and Chief Medical Officer Eric Crombez reported a mix of stock award and sale transactions. On March 1, 2026, he acquired 11,643 shares of common stock at $0.00 per share through a grant, as previously granted performance stock units converted upon certification of performance metrics. On March 2, 2026, he executed an open-market sale of 7,029 shares of common stock at a weighted average price of $22.80 per share, with actual prices ranging from $22.54 to $23.11. A footnote states these shares were sold to pay required tax withholdings related to the vesting of restricted stock units. Following these transactions, Crombez directly held 76,301 shares of Ultragenyx common stock, which includes shares acquired under the company’s employee stock purchase plan and shares underlying restricted stock units that remain subject to vesting conditions.

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^*

Crombez Eric

(Last) (First) (Middle)

C/O ULTRAGENYX PHARMACEUTICAL INC.

60 LEVERONI COURT

(Street)

NOVATO CA 94949

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Ultragenyx Pharmaceutical Inc. [ RARE ]

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

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	EVP and Chief Medical Officer

3. Date of Earliest Transaction (Month/Day/Year)
03/01/2026

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	03/01/2026		A		11,643(1)	A	$0	83,173	D
Common Stock	03/02/2026		S		7,029(2)	D	$22.8(3)	76,301(4)(5)	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. Represents shares of common stock which previously granted performance stock units were converted on March 1, 2026 upon certification of the performance metrics.

2. Represents shares sold to pay required tax withholdings due to the vesting of RSUs.

3. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $22.54 to $23.11 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

4. Includes 157 shares acquired on October 30, 2025 under the Company's Amended and Restated Employee Stock Purchase Plan

5. Includes previously reported shares of common stock underlying RSUs granted to the Reporting Person, which are subject to certain vesting conditions.

	/s/ Karah Parschauer, attorney-in-fact	03/03/2026
	** 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).
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FAQ

What did Ultragenyx (RARE) EVP Eric Crombez report in this Form 4?

Eric Crombez reported a stock award and a stock sale. He received 11,643 Ultragenyx common shares via a grant, then sold 7,029 shares in an open-market transaction primarily to cover tax withholdings tied to vesting restricted stock units.

How many Ultragenyx (RARE) shares did Eric Crombez acquire in the latest award?

He acquired 11,643 shares of Ultragenyx common stock at $0.00 per share. These shares reflect performance stock units that converted on March 1, 2026, after the company certified that the related performance metrics had been achieved.

How many Ultragenyx (RARE) shares did Eric Crombez sell and at what price?

He sold 7,029 shares of Ultragenyx common stock at a weighted average price of $22.80. The transactions occurred between $22.54 and $23.11 per share, and the shares were sold to satisfy required tax withholding obligations from RSU vesting.

Why were some Ultragenyx (RARE) shares sold by Eric Crombez in this filing?

The filing states the 7,029 shares were sold to pay required tax withholdings. These tax obligations arose due to the vesting of restricted stock units previously granted to Eric Crombez under Ultragenyx’s equity compensation programs.

How many Ultragenyx (RARE) shares does Eric Crombez hold after these transactions?

After the reported award and sale, Eric Crombez directly holds 76,301 Ultragenyx common shares. This figure includes 157 shares from the employee stock purchase plan and shares underlying restricted stock units that continue to be subject to vesting conditions.

What additional details are disclosed about Eric Crombez’s Ultragenyx (RARE) equity holdings?

His holdings include shares acquired through Ultragenyx’s Amended and Restated Employee Stock Purchase Plan. The total also reflects previously reported shares underlying restricted stock units, which remain subject to specified vesting requirements before becoming fully owned.