# EDGAR Filing Document

**Accession Number:** 0001515673
**File Stem:** 0000950170-25-094806
**Filing Date:** 2025-7
**Character Count:** 7480
**Document Hash:** d11278c587a2854becdd312a85895356
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0000950170-25-094806.hdr.sgml**: 20250709

**ACCESSION NUMBER**: 0000950170-25-094806

**CONFORMED SUBMISSION TYPE**: 8-K

**PUBLIC DOCUMENT COUNT**: 10

**CONFORMED PERIOD OF REPORT**: 20250709

**ITEM INFORMATION**: Other Events

**FILED AS OF DATE**: 20250709

**DATE AS OF CHANGE**: 20250709

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Ultragenyx Pharmaceutical Inc.
- **CENTRAL INDEX KEY:** 0001515673
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 272546083
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 8-K
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-36276
- **FILM NUMBER:** 251113928

**BUSINESS ADDRESS:**
- **STREET 1:** 60 LEVERONI COURT
- **CITY:** NOVATO
- **STATE:** CA
- **ZIP:** 94949
- **BUSINESS PHONE:** 415-483-8800

**MAIL ADDRESS:**
- **STREET 1:** 60 LEVERONI COURT
- **CITY:** NOVATO
- **STATE:** CA
- **ZIP:** 94949

?xml version='1.0' encoding='ASCII'? 8-K

**UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549**

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## **FORM** 8-K

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**CURRENT REPORT**

**Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934**

**Date of Report (Date of earliest event reported):** July 09, 2025<br>

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Ultragenyx Pharmaceutical Inc.

**(Exact name of Registrant as Specified in Its Charter)**

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| | | |
|:---|:---|:---|
| Delaware | 001-36276 | 27-2546083 |
| **(State or Other Jurisdiction<br>of Incorporation)** | **(Commission File Number)** | **(IRS Employer<br>Identification No.)** |
| 60 Leveroni Court |  |  |
| Novato**,** California |  | 94949 |
| **(Address of Principal Executive Offices)** |  | **(Zip Code)** |

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**Registrant's Telephone Number, Including Area Code:** 415 483-8800<br>

**(Former Name or Former Address, if Changed Since Last Report)**

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Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

**Securities registered pursuant to Section 12(b) of the Act:**

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| | | |
|:---|:---|:---|
| **<br>Title of each class** | **Trading<br>Symbol(s)** | **<br>Name of each exchange on which registered** |
| Common Stock, $0.001 par value | RARE | Nasdaq Global Select Market |

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Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

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| | |
|:---|:---|
| **Item 8.01** | **Other Events.**  |

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On July 9, 2025, Ultragenyx Pharmaceutical Inc. (the "Company") announced that the randomized, placebo-controlled Phase 3 portion of the *Orbit* study evaluating UX143 (setrusumab) in pediatric and young adult patients with osteogenesis imperfecta ("OI") is progressing toward a final analysis consistent with the original plan, around the end of the year.

The Data Monitoring Committee (the "DMC") met and informed the Company that UX143 demonstrates an acceptable safety profile and the Company should continue the study to the final analysis.

Consistent with the statistical analysis plan, data from the UX143 *Cosmic* study were not analyzed at this interim timepoint. Study conduct is going well and safety in this younger patient population is consistent with the safety profile in the other studies.

Patients will continue dosing in the ongoing Phase 3 *Orbit* and *Cosmic* clinical studies with the final analyses to be conducted after patients have been on therapy for at least 18 months. The threshold for the Phase 3 *Orbit* final analysis is p<0.04 and for the Phase 3 *Cosmic* final analysis is p<0.05.

***Cautionary Note Regarding Forward-Looking Statements***

This Current Report on Form 8-K contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. These statements may be identified by the use of words such as, but not limited to, "anticipates," "continue," "will," or other similar terms or expressions that concern the Company's expectations, plans and intentions. Forward-looking statements include, without limitation, statements regarding the clinical benefit, tolerability and safety of UX143, the Company's expectations and projections regarding its future operating results and financial performance, business plans and objectives for UX143, and future clinical and regulatory developments for UX143, including the timing of the final analysis of the Phase 3 studies for UX143 and the outcomes from such studies. Such forward-looking statements involve substantial risks and uncertainties including, among others, the uncertainty of clinical drug development and unpredictability and lengthy process for obtaining regulatory approvals, the ability of the Company to successfully develop UX143, the Company's ability to achieve its projected development goals in its expected timeframes, the risk that results from earlier studies may not be predictive of future study results, risks related to adverse side effects, risks related to reliance on third party partners to conduct certain activities on the Company's behalf, smaller than anticipated market opportunities for the Company's products and product candidates, manufacturing risks, competition from other therapies or products, and other matters that could affect the sufficiency of existing cash, cash equivalents and short-term investments to fund operations, the Company's future operating results and financial performance, the timing of clinical trial activities and reporting results from same, and the availability or commercial potential of the Company's products and drug candidates. The Company undertakes no obligation to update or revise any forward-looking statements. For a further description of the risks and uncertainties that could cause actual results to differ from those expressed in these forward-looking statements, as well as risks relating to the business of the Company in general, see the Company's Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission (SEC) on May 7, 2025, and its subsequent periodic reports filed with the SEC.

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**SIGNATURES**

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

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| | | | |
|:---|:---|:---|:---|
|  |  |  | Ultragenyx Pharmaceutical Inc. |
| Date: | July 9, 2025 | By:  | /s/ Howard Horn |
|  |  |  | Howard Horn <br>Executive Vice President, Chief Financial Officer, Corporate Strategy |

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