Ultragenyx Pharmaceutical Inc. filings document a rare-disease biopharmaceutical business with approved medicines, investigational genetic-disease therapies, and a Nasdaq-listed common stock capital structure. Form 8-K reports include operating results, financial guidance, FDA communications, clinical-study data, and risk language tied to drug development, regulatory review, manufacturing, funding needs, competition, and commercialization.
Proxy materials describe annual-meeting matters, board and compensation governance, equity compensation, and stockholder voting. Recent current reports also record restructuring and cost disclosures, employment-related equity plans, and material updates for programs including UX111, UX016, DTX301, DTX401, and GTX-102.
Ultragenyx reported that the first patient has been dosed in the global Aurora study (NCT07157254) evaluating GTX-102 (apazunersen), an investigational antisense oligonucleotide for Angelman syndrome.
Aurora plans to enroll approximately 60 participants ages one to less than 65 across all genotypes in four cohorts. Cohorts A–C are single-arm; Cohort D is randomized 2:1 to GTX-102 or No Treatment, with a 48-week primary efficacy period and crossover at Week 24. Participants may continue in a long-term extension after study completion.
The Phase 3 Aspire study (NCT06617429) is fully enrolled, with 129 participants ages four to 17 with full maternal UBE3A gene deletion randomized across 28 global sites. Data from Aspire are expected in the second half of 2026.
Ultragenyx Pharmaceutical (RARE) insider activity: The company’s Chief Financial Officer reported a sale of common stock on 10/13/2025. The filing shows 7,942 shares were sold at $31.51 per share.
According to the explanation, these shares were sold to pay required tax withholdings related to the vesting of restricted stock units (RSUs). Following the transaction, the reporting person beneficially owned 98,227 shares. The ownership is listed as direct.
The filing notes that the remaining amount includes previously reported shares underlying RSUs that are subject to vesting conditions.
Theodore Alan Huizenga, SVP and Chief Accounting Officer and director of Ultragenyx Pharmaceutical Inc. (RARE), reported a sale of 64 shares of common stock on 09/18/2025 at a price of $29.17 per share. The filing states the shares were sold to pay required tax withholdings related to the vesting of restricted stock units (RSUs). After the transaction, the reporting person beneficially owned 50,242 shares. The Form 4 was signed by an attorney-in-fact on 09/19/2025.
Ultragenyx Pharmaceutical Inc. reported positive longer-term Phase 3 results for its DTX401 gene therapy in glycogen storage disease type Ia. Patients treated with DTX401 showed a 41% mean reduction in daily cornstarch intake at Week 48 versus 10% with placebo, while maintaining glycemic control. By Week 96, both the original DTX401 group and a crossover group achieved a 61% mean reduction in daily cornstarch, with nighttime cornstarch reduced by 70% and 75% respectively and two-thirds of participants eliminating at least one nighttime dose. Quality-of-life measures improved, with 83% and 95% of patients in the two groups reporting lower disease burden, and safety remained acceptable without observed AAV8 class effects such as dorsal root ganglion toxicity, malignancy or thrombotic microangiopathy.
Theodore A. Huizenga, SVP and Chief Accounting Officer of Ultragenyx Pharmaceutical Inc. (RARE), reported a sale of company common stock on 09/05/2025. The Form 4 shows a sale (Code S) of 84 shares at $31.39 per share. After the reported transaction the reporting person beneficially owned 50,306 shares directly. The filing explains the sale represents shares sold to pay required tax withholdings upon vesting of restricted stock units, and also notes the reporting person acquired 266 shares under the company’s Employee Stock Purchase Plan on April 30, 2025. Previously reported RSU-related shares subject to vesting are included in the total.
Ultragenyx Pharmaceutical Inc. reported that it has begun a rolling submission of a Biologics License Application to the U.S. FDA for DTX401, an AAV gene therapy for Glycogen Storage Disease Type Ia. The company has submitted the non-clinical and clinical modules and plans to complete the full application, including the chemistry, manufacturing and controls module, in the fourth quarter of 2025.
The BLA will include 96-week data from a Phase 3 trial showing patients had greater reductions in total daily cornstarch from baseline at their last visit, with a -60% reduction in the ongoing DTX401 group and -64% in the Crossover Placebo to DTX401 group compared to the 48-week data. Ultragenyx also plans to incorporate updates in the CMC section to proactively address FDA observations from the UX111 complete response letter and at its gene therapy manufacturing facilities.