Topline results from the Phase III SUMMIT trial showed Satsuma Pharmaceuticals’ migraine candidate STS101 did not meet its primary efficacy endpoint.
Topline results from the Phase III SUMMIT trial showed Satsuma Pharmaceuticals’ migraine candidate STS101 did not meet its primary efficacy endpoint, the California company announced Monday.
A 5.2-mg dose of STS101 could not significantly differentiate itself from placebo in terms of the study’s pre-specified co-primary endpoints of freedom from pain and the most bothersome symptom two hours after treatment.
The company’s shares dropped 80% Monday morning in reaction to the news.
Satsuma also announced that it does not plan to invest resources into the commercialization activities for STS101. The company will instead explore alternative options to maximize shareholder value while minimizing expenditures.
Despite falling short of its efficacy target, Satsuma believes that pharmacokinetic data from early-stage trials, as well as STS101’s promising safety and tolerability profile, will be enough to support a new drug application for the candidate.
In a statement, John Kollins, president and CEO of Satsuma, said that the company is “disappointed” that their candidate missed its primary endpoint and “did not demonstrate statistically significant superiority over placebo.”
The Silver Lining
However, taking both components of the primary endpoint separately revealed significant clinical benefits associated with Satsuma’s candidate.
At three hours post-dose, for instance, there was a significantly higher percentage of patients free from pain in the STS101 arm than in placebo, with a p-value of 0.0002. This remained true for all other subsequent time points until 48 hours after treatment.
Similar trends were reported for freedom from the most bothersome syndrome, with a significantly higher percentage of responders in the STS101 arm starting at three hours post-dose.
STS is a nasal powder formulation of dihydroergotamine mesylate (DHE), a well-established migraine treatment. The candidate is delivered via a nasal spray using Satsuma’s proprietary device. Previous studies have shown that STS101 can be quickly absorbed and leads to a rapid increase in plasma DHE levels.
SUMMIT, a randomized, double-blinded and parallel-group study, is designed to assess the efficacy of Satsuma’s novel DHE formulation and delivery. Aside from the co-primary endpoints, the trial also evaluated STS101 according to several clinically relevant secondary endpoints.
Satsuma’s candidate performed significantly better than placebo in many of these benchmarks, including the proportion of patients with pain relief at 2 hours post-dose and the proportion of patients needing rescue medication 24 and 48 hours after treatment. Sustained freedom from pain for 24 hours was also significantly higher in the STS101 arm.
Aside from SUMMIT, Satsuma has also run the Phase III ASCEND trial, an open-label, 12-month study focused on the safety and tolerability of STS101 at a 5.2-mg dose. In September, the company announced positive results from ASCEND, showing no clinically relevant nasal or systemic safety signals across more than 6,900 doses in 344 study participants.
The most common side effects in ASCEND were nasal discomfort and dysgeusia, arising in 11% and 7.6% of participants, respectively. Most toxicities were mild and transient.
