SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES 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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1. Name and Address of Reporting Person* FMR LLC (Last) (First) (Middle) 245 SUMMER STREET (Street) BOSTON MA 02210 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 01/30/2014	3. Issuer Name and Ticker or Trading Symbol Ultragenyx Pharmaceutical Inc. [ RARE ]
		4. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director X 10% Owner Officer (give title below) X Other (specify below) Edward C. Johnson 3d	5. 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 Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Series A Convertible Preferred Stock	(1)	(1)	Common Stock	9,129,063	(1)	I	by Beacon Bioventures Fund II Limited Partnership
Series B Convertible Preferred Stock	(1)	(1)	Common Stock	541,634	(1)	I	by Beacon Bioventures Fund II Limited Partnership

Explanation of Responses:

1. All classes of Convertible Preferred Stock automatically convert into Common Stock, on a 3.1345-for-1 basis, upon the consummation of the initial public offering of Common Stock by the Issuer. The number of underlying shares of Common Stock reported in Column 3 does not reflect the conversion of 3.1345 Convertible Preferred Stock for 1 Common Stock.

Remarks:

Beacon Bioventures Advisors Fund II Limited Partnership is the general partner of Beacon Bioventures Fund II Limited Partnership. Beacon Bioventures Advisors Fund II Limited Partnership is solely managed by Northern Neck Investors LLC, its general partner and investment manager. Northern Neck Investors LLC is owned, directly or indirectly, by various shareholders and employees of FMR LLC, including certain members of the family of Edward C. Johnson 3d.

	Scott C. Goebel, Duly authorized under Powers of Attorney effective as of June 1, 2008, by and on behalf of FMR LLC and its direct and indirect subsidiaries, and by and on behalf of Edward C. Johnson 3d	02/05/2014
	** 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 5 (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).
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