It's been a rough Thursday for Ultragenyx Pharmaceutical Inc. (RARE). The biopharmaceutical company's stock is taking a beating after it announced that its late-stage clinical trial for apazunersen, a potential treatment for Angelman syndrome, failed to hit its goals. As a result, the company is now looking at the program's future and planning some serious cost-cutting.
Ultragenyx's Angelman Syndrome Drug Fails Late-Stage Trial, Stock Plunges
MarketDash
Ultragenyx's Phase 3 Aspire study of apazunersen misses primary and key secondary endpoints, leading to a strategic review and significant cost-cutting plans.
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What's Apazunersen and Why Does It Matter?
Apazunersen is an experimental therapy designed to treat Angelman syndrome, a rare neurogenetic disorder. The condition is caused by a loss-of-function in the maternally inherited UBE3A gene allele, leading to cognitive and motor impairments, balance issues, and seizures. Apazunersen works by inhibiting UBE3A-AS expression, which is a key player in the disease's mechanism.
The Trial Results Were Disappointing
The Phase 3 Aspire study evaluated apazunersen, also known as GTX-102, in patients with Angelman syndrome. The primary endpoint was the change from baseline in the Bayley-4 cognitive raw score, which measures developmental functioning and potential delays in infants and toddlers from 16 days to 42 months old. Unfortunately, the trial missed this primary endpoint.
It also failed its key secondary endpoint, which was the net response on the Multidomain Responder Index, a tool used to capture a broader assessment of clinical benefit. While the randomized treatment groups were comparable at baseline, mirroring patient demographics from Phase 2 trials, there were no efficacy differences between treated and control groups in Bayley Cognition raw scores or net response across the five individual endpoints in the responder index.
On the safety front, apazunersen maintained a profile consistent with earlier Phase 1/2 testing, so at least there were no new safety concerns.
What's Next for Ultragenyx?
Following these results, management is planning to evaluate the apazunersen program to decide its ultimate fate. The company will also assess its operations to implement significant expense reductions while still supporting its growing commercial business. It's a tough spot, but the company is clearly trying to pivot and focus on what's working.
Investors didn't take the news well. Ultragenyx shares were down 47.57% at $13.91 during premarket trading on Thursday, hitting a new 52-week low. It's a stark reminder of how high the stakes are in biotech, where a single trial failure can wipe out a significant chunk of market value.
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