Ultragenyx's DTX401 Gene Therapy Receives FDA Priority Review
Written by Emily J. Thompson, Senior Investment Analyst
Updated: Feb 23 2026
0mins
Should l Buy RARE?
Ultragenyx Pharmaceutical announced the U.S. Food and Drug Administration, FDA, has accepted for review the Biologics License Application, BLA, seeking approval of DTX401 AAV gene therapy for the treatment of Glycogen Storage Disease Type Ia. The FDA granted the BLA Priority Review and assigned a Prescription Drug User Fee Act, PDUFA, action date of August 23, 2026. "Current dietary approaches to managing GSDIa place an extraordinary burden on individuals and families while still leaving patients with significant medical needs, including the risk of potentially life-threatening episodes of acute hypoglycemia and accumulation of long-term complications over their lifetime," said Eric Crombez, M.D., chief medical officer at Ultragenyx. "If approved, DTX401 would be the first treatment to address the disease at its root cause. We appreciate the FDA's timely acceptance of the BLA and will continue to work with the Agency throughout its review process."
Trade with 70% Backtested Accuracy
Stop guessing "Should I Buy RARE?" and start using high-conviction signals backed by rigorous historical data.
Sign up today to access powerful investing tools and make smarter, data-driven decisions.
Analyst Views on RARE
Wall Street analysts forecast RARE stock price to rise
18 Analyst Rating
17 Buy
1 Hold
0 Sell
Strong Buy
Current: 23.020
Low
35.00
Averages
61.65
High
120.00
Current: 23.020
Low
35.00
Averages
61.65
High
120.00
About RARE
Ultragenyx Pharmaceutical Inc. is a biopharmaceutical company. The Company is focused on the identification, acquisition, development, and commercialization of novel products for the treatment of serious rare and ultrarare genetic diseases. Its therapies and clinical-stage pipeline consist of four product categories: biologics, small molecules, AAV gene therapy, and nucleic acid product candidates. Its four approved product candidates include Crysvita (burosumab) for the treatment of X-linked hypophosphatemia (XLH), and tumor-induced osteomalacia (TIO), Mepsevii (vestronidase alfa) for the treatment of mucopolysaccharidosis VII (MPSVII) or Sly Syndrome, Dojolvi (triheptanoin) for the treatment of long-chain fatty acid oxidation disorders (LC-FAOD), and Evkeeza (evinacumab) for the treatment of homozygous familial hypercholesterolemia (HoFH). Its clinical product candidates include DTX401, DTX301, UX701, UX143, UX111, and GTX-102. UX143 for the treatment of Osteogenesis Imperfecta.
About the author
Emily J. Thompson
Emily J. Thompson, a Chartered Financial Analyst (CFA) with 12 years in investment research, graduated with honors from the Wharton School. Specializing in industrial and technology stocks, she provides in-depth analysis for Intellectia’s earnings and market brief reports.
Ultragenyx Pharmaceutical Securities Lawsuit Notification
- Lawsuit Background: Kahn Swick & Foti LLC informs investors in Ultragenyx Pharmaceutical of a class action lawsuit due to alleged securities fraud occurring between August 3, 2023, and December 26, 2025, aimed at recovering losses for affected investors.
- Study Failure Impact: On December 26, 2025, Ultragenyx announced that its Phase 3 studies for setrusumab (UX143) failed to show a statistically significant reduction in annualized fracture rates for osteogenesis imperfecta patients, prompting the company to evaluate significant expense reductions.
- Stock Price Plunge: Following the announcement, Ultragenyx's stock price fell approximately 42%, from $34.19 per share on December 26, 2025, to $19.72 per share on December 29, 2025, indicating a negative market outlook on the company's future.
- Investor Action Recommendation: Affected investors have until April 6, 2026, to request to be appointed as lead plaintiff, although they can still share in any recovery without serving in that role, highlighting ongoing opportunities for legal recourse for investors seeking compensation.
See More
FDA Faces Criticism Amid Innovation Challenges
- Regulatory Standards Controversy: Congressman Jake Auchincloss criticized FDA Commissioner Marty Makary for replacing standards of safety and efficacy with fear and favoritism, undermining patient confidence in new therapies and impacting the market launch of innovative drugs.
- Staffing Losses: The FDA has experienced significant staff reductions in its Center for Drug Evaluation and Research, with oncology review staff dropping from about 100 to below 60, which may lead to approval delays and incomplete response letters.
- Decline in Accelerated Approvals: In 2024, the FDA approved 20 drugs through the accelerated approval process, down from 9 the previous year, indicating a direct impact on drug approval efficiency due to the loss of experienced reviewers.
- New Therapy Approval Pathways: The FDA proposed a new system for approving personalized drugs aimed at rare diseases, intending to provide more flexible approval pathways, but this change has sparked widespread controversy, affecting the agency's core mission.
See More
Ultragenyx Pharmaceutical Class Action Notice Issued
- Class Action Notice: Rosen Law Firm reminds investors who purchased Ultragenyx (NASDAQ:RARE) common stock between August 3, 2023, and December 26, 2025, to apply as lead plaintiffs by April 6, 2026, to protect their rights in the lawsuit.
- Fee Arrangement: Investors joining the class action will incur no out-of-pocket costs, as attorney fees will be covered through a contingency fee arrangement, thereby reducing financial barriers and encouraging broader participation from affected shareholders.
- Lawsuit Background: The lawsuit alleges that Ultragenyx made false statements regarding the efficacy of setrusumab in its Phase III Orbit and Cosmic studies, leading investors to purchase shares at artificially inflated prices, resulting in financial losses when the truth emerged.
- Law Firm's Advantage: Rosen Law Firm is renowned for its successful track record in securities class actions, having recovered over $438 million for investors in 2019 alone, demonstrating its expertise and resource capabilities in handling such cases.
See More
Ultragenyx Faces Class Action Lawsuit Over Securities Fraud
- Class Action Filed: Pomerantz LLP has announced a class action lawsuit against Ultragenyx Pharmaceutical, alleging securities fraud and unlawful business practices by the company and certain officers, with investors needing to apply as Lead Plaintiff by April 6, 2026.
- Stock Price Volatility: Following news of the final analysis for the Orbit study on July 10, 2025, Ultragenyx's stock plummeted by $10.41, a 25.11% drop, closing at $31.04 per share, indicating strong market reaction to the clinical trial results.
- Clinical Trial Failures: On December 29, 2025, Ultragenyx announced that both its Phase III Orbit and Cosmic studies failed to achieve statistical significance on primary endpoints, resulting in a further stock decline of $14.47, or 42.32%, closing at $34.19 per share, reflecting a severe loss of investor confidence in the company's future.
- Legal Firm Reputation: Pomerantz LLP, a leading firm in securities class litigation with over 85 years of experience, is known for advocating for victims of securities fraud and corporate misconduct, underscoring its expertise and influence in handling such cases.
See More
Ultragenyx Pharmaceutical Faces Securities Fraud Class Action Lawsuit
- Lawsuit Background: Kessler Topaz Meltzer & Check, LLP has filed a securities fraud class action against Ultragenyx Pharmaceutical on behalf of investors who purchased shares between August 3, 2023, and December 26, 2025, indicating a significant erosion of investor trust in the company.
- Stock Price Plunge: On December 29, 2025, Ultragenyx shocked the market by revealing that its clinical trials failed to achieve statistical significance, causing its stock price to plummet 42% from $34.19 to $19.72, reflecting extreme disappointment in the company's prospects.
- False Statement Allegations: The lawsuit alleges that Ultragenyx misled investors regarding the efficacy of its drug for Osteogenesis Imperfecta, failing to disclose risks associated with its clinical trials, which exacerbated investor losses.
- Investor Action Recommendations: Affected investors are encouraged to seek lead plaintiff status by April 6, 2026, to represent the class in litigation, highlighting the importance of legal avenues in protecting investor rights.
See More
Class Action Filed Against Ultragenyx Pharmaceutical Inc.
- Lawsuit Background: Bronstein, Gewirtz & Grossman, LLC, a nationally recognized investor-rights law firm, has filed a class action lawsuit against Ultragenyx Pharmaceutical Inc. and certain officers, seeking damages for investors who purchased securities between August 3, 2023, and December 26, 2025, highlighting significant investor concerns regarding corporate transparency.
- Allegations of Misrepresentation: The complaint alleges that throughout the class period, the defendants made false and/or misleading statements and failed to disclose risks associated with the Phase III Orbit study on Osteogenesis Imperfecta, potentially leading investors to misjudge the company's prospects and the reliability of its data.
- Investor Action: Affected investors are encouraged to apply to be lead plaintiffs by April 6, 2026, to share in any recovery from the lawsuit, underscoring the importance of legal recourse in protecting investor rights and interests.
- Law Firm's Credentials: Bronstein, Gewirtz & Grossman, LLC has a strong reputation in securities fraud class actions, having recovered hundreds of millions for investors nationwide, emphasizing their commitment to restoring investor capital and ensuring market integrity.
See More
Ultragenyx Pharmaceutical Securities Lawsuit Notification
- Lawsuit Background: Kahn Swick & Foti LLC informs investors in Ultragenyx Pharmaceutical of a class action lawsuit due to alleged securities fraud occurring between August 3, 2023, and December 26, 2025, aimed at recovering losses for affected investors.
- Study Failure Impact: On December 26, 2025, Ultragenyx announced that its Phase 3 studies for setrusumab (UX143) failed to show a statistically significant reduction in annualized fracture rates for osteogenesis imperfecta patients, prompting the company to evaluate significant expense reductions.
- Stock Price Plunge: Following the announcement, Ultragenyx's stock price fell approximately 42%, from $34.19 per share on December 26, 2025, to $19.72 per share on December 29, 2025, indicating a negative market outlook on the company's future.
- Investor Action Recommendation: Affected investors have until April 6, 2026, to request to be appointed as lead plaintiff, although they can still share in any recovery without serving in that role, highlighting ongoing opportunities for legal recourse for investors seeking compensation.
See More
FDA Faces Criticism Amid Innovation Challenges
- Regulatory Standards Controversy: Congressman Jake Auchincloss criticized FDA Commissioner Marty Makary for replacing standards of safety and efficacy with fear and favoritism, undermining patient confidence in new therapies and impacting the market launch of innovative drugs.
- Staffing Losses: The FDA has experienced significant staff reductions in its Center for Drug Evaluation and Research, with oncology review staff dropping from about 100 to below 60, which may lead to approval delays and incomplete response letters.
- Decline in Accelerated Approvals: In 2024, the FDA approved 20 drugs through the accelerated approval process, down from 9 the previous year, indicating a direct impact on drug approval efficiency due to the loss of experienced reviewers.
- New Therapy Approval Pathways: The FDA proposed a new system for approving personalized drugs aimed at rare diseases, intending to provide more flexible approval pathways, but this change has sparked widespread controversy, affecting the agency's core mission.
See More
Ultragenyx Pharmaceutical Class Action Notice Issued
- Class Action Notice: Rosen Law Firm reminds investors who purchased Ultragenyx (NASDAQ:RARE) common stock between August 3, 2023, and December 26, 2025, to apply as lead plaintiffs by April 6, 2026, to protect their rights in the lawsuit.
- Fee Arrangement: Investors joining the class action will incur no out-of-pocket costs, as attorney fees will be covered through a contingency fee arrangement, thereby reducing financial barriers and encouraging broader participation from affected shareholders.
- Lawsuit Background: The lawsuit alleges that Ultragenyx made false statements regarding the efficacy of setrusumab in its Phase III Orbit and Cosmic studies, leading investors to purchase shares at artificially inflated prices, resulting in financial losses when the truth emerged.
- Law Firm's Advantage: Rosen Law Firm is renowned for its successful track record in securities class actions, having recovered over $438 million for investors in 2019 alone, demonstrating its expertise and resource capabilities in handling such cases.
See More
Ultragenyx Faces Class Action Lawsuit Over Securities Fraud
- Class Action Filed: Pomerantz LLP has announced a class action lawsuit against Ultragenyx Pharmaceutical, alleging securities fraud and unlawful business practices by the company and certain officers, with investors needing to apply as Lead Plaintiff by April 6, 2026.
- Stock Price Volatility: Following news of the final analysis for the Orbit study on July 10, 2025, Ultragenyx's stock plummeted by $10.41, a 25.11% drop, closing at $31.04 per share, indicating strong market reaction to the clinical trial results.
- Clinical Trial Failures: On December 29, 2025, Ultragenyx announced that both its Phase III Orbit and Cosmic studies failed to achieve statistical significance on primary endpoints, resulting in a further stock decline of $14.47, or 42.32%, closing at $34.19 per share, reflecting a severe loss of investor confidence in the company's future.
- Legal Firm Reputation: Pomerantz LLP, a leading firm in securities class litigation with over 85 years of experience, is known for advocating for victims of securities fraud and corporate misconduct, underscoring its expertise and influence in handling such cases.
See More
Ultragenyx Pharmaceutical Faces Securities Fraud Class Action Lawsuit
- Lawsuit Background: Kessler Topaz Meltzer & Check, LLP has filed a securities fraud class action against Ultragenyx Pharmaceutical on behalf of investors who purchased shares between August 3, 2023, and December 26, 2025, indicating a significant erosion of investor trust in the company.
- Stock Price Plunge: On December 29, 2025, Ultragenyx shocked the market by revealing that its clinical trials failed to achieve statistical significance, causing its stock price to plummet 42% from $34.19 to $19.72, reflecting extreme disappointment in the company's prospects.
- False Statement Allegations: The lawsuit alleges that Ultragenyx misled investors regarding the efficacy of its drug for Osteogenesis Imperfecta, failing to disclose risks associated with its clinical trials, which exacerbated investor losses.
- Investor Action Recommendations: Affected investors are encouraged to seek lead plaintiff status by April 6, 2026, to represent the class in litigation, highlighting the importance of legal avenues in protecting investor rights.
See More
Class Action Filed Against Ultragenyx Pharmaceutical Inc.
- Lawsuit Background: Bronstein, Gewirtz & Grossman, LLC, a nationally recognized investor-rights law firm, has filed a class action lawsuit against Ultragenyx Pharmaceutical Inc. and certain officers, seeking damages for investors who purchased securities between August 3, 2023, and December 26, 2025, highlighting significant investor concerns regarding corporate transparency.
- Allegations of Misrepresentation: The complaint alleges that throughout the class period, the defendants made false and/or misleading statements and failed to disclose risks associated with the Phase III Orbit study on Osteogenesis Imperfecta, potentially leading investors to misjudge the company's prospects and the reliability of its data.
- Investor Action: Affected investors are encouraged to apply to be lead plaintiffs by April 6, 2026, to share in any recovery from the lawsuit, underscoring the importance of legal recourse in protecting investor rights and interests.
- Law Firm's Credentials: Bronstein, Gewirtz & Grossman, LLC has a strong reputation in securities fraud class actions, having recovered hundreds of millions for investors nationwide, emphasizing their commitment to restoring investor capital and ensuring market integrity.
See More
