RARE Stock Clocks Two Consecutive Days Of Losses Ahead Of Weekend FDA Decision On Gene Therapy
RARE
Key points:
- DTX401 aims to fix the underlying problem by delivering a working gene.
- An approval would mark a major step for Ultragenyx’s shift toward gene therapies in rare diseases.
- However, the decision may be delayed, as shown by the FDA’s delay with Replimune’s RP1 decision earlier this month.
Shares of Ultragenyx Pharmaceutical (RARE) fell for the second consecutive day on Tuesday ahead of a closely watched U.S. Food and Drug Administration decision on its gene therapy slated for this weekend
The stock fell 2.5% on Tuesday after closing down 1% on Monday
The FDA is due to rule by August 23 on Ultragenyx’s application for DTX401, a one-time gene therapy for glycogen storage disease type Ia (GSDIa), also known as von Gierke disease. This rare genetic condition prevents the body from properly breaking down stored sugar, forcing patients to take cornstarch frequently—day and night—to avoid dangerous drops in blood sugar and long-term complications
DTX401 aims to fix the underlying problem by delivering a working gene. Trial results showed patients needed far less cornstarch while keeping blood sugar more stable and lasting longer between meals. The review has Priority status. If cleared, it would be the first treatment to address the root cause of GSDIa rather than just manage symptoms
Why It Matters For The Pipeline
An approval would mark a major step for Ultragenyx’s shift toward gene therapies in rare diseases. The company already sells medicines such as Crysvita and Dojolvi. Success with DTX401 would add a new growth driver in a condition affecting thousands of patients and strengthen its position as a leader in ultra-rare genetic disorders
It also sets the stage for a second potential approval later in September for another gene therapy targeting Sanfilippo syndrome. Together, these could accelerate the path toward profitability the company has outlined for 2027
Echoes Of Recent Weekend Delay
However, the decision may be delayed, as shown by the FDA’s delay with Replimune’s RP1 decision. FDA decision on Replimune’s melanoma therapy was due on August 2—a Sunday. No announcement arrived over the weekend. The agency instead acted several days later after markets closed mid-week
Ultragenyx’s August 23 target lands on a Sunday as well, raising the possibility of a similar lag into the following week
How Did RARE Retail Traders React?
On Stocktwits, retail sentiment around RARE stock stayed within the bullish territory over the past 24 hours, while message volume stayed at normal levels
A Stocktwits user expressed frustration at the stock selloff ahead of the potential approval
Another user noted that the stock has near-term catalysts beyond the weekend FDA decision as well
RARE stockhas risen 11% year-to-date
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