Satsuma Pharma’s Migraine Drug Fails to Beat Placebo in Phase 3 Test

Xconomy San Francisco — 

[Updated, 7:31 p.m. EDT. See below.] An experimental Satsuma Pharmaceuticals treatment for acute migraine has failed a late-stage clinical trial, dealing a setback to the company’s plans to offer another therapeutic option to the millions of people who suffer from the condition.

In Phase 3 results released Thursday, South San Francisco-based Satusuma (NASDAQ: STSA) reported that preliminary data showed both doses of its experimental treatment, STS101, led to improvement in measures of pain and other symptoms. But those differences, compared to a placebo, were not enough to be statistically significant.

Shares of Satsuma plummeted on the news, opening Thursday at $4.80 apiece, down nearly 80 percent from Wednesday’s closing price.

The clinical trial results released Thursday come one year after Satusma raised $82.5 million from its IPO, which financed the Phase 3 test of STS101. The experimental Satsuma treatment is a drug and medical device combination product designed to administer a dry powder formulation of dihydroergotamine mesylate (DHE), a drug use to treat acute migraine. Though the generic drug is already available in injectable and nasal spray formulations, Satsuma has said that its dry powder version of the drug delivered by its proprietary device could offer patients an easier to administer treatment option that provides faster migraine relief.

The Phase 3 study enrolled more than 1,140 migraine patients in the US who were randomly assigned to three groups: one each for the low and high doses of the Satsuma drug and a third cohort given a placebo. Those patients were instructed to use the experimental treatment for their next migraine attack. The two main goals of the study were measuring freedom from pain and freedom from the most bothersome migraine symptoms, such as light sound sensitivity, as well as nausea. Those measures were assessed two hours after taking the study medication.

Though the experimental migraine treatment did not distance itself from a placebo, Satsuma said that at the three-hour mark and later, both doses of STS101 demonstrated “significant effects” on the measures of pain and other symptoms. The drug was well tolerated by patients and no serious adverse events were reported.

[The following two paragraphs added with analyst comment.] In a Thursday research note, SVB Leerink analyst Marc Goodman wrote that the clinical trial results were surprising given that DHE is a well-known molecule used for many years to treat migraine pain. He added that the drug’s better performance after three hours suggests a slower onset of effect, but that might not be enough to win FDA approval. Many of the approved treatments for acute migraine have demonstrated that they work within two hours, an established marker for showing efficacy in treating migraine, he wrote.

According to the note, Satsuma management told Goodman that the next steps for the company include slimming down spending and merging with another company looking to go public, or filing for FDA approval of STS101 based only on pharmacokinetic and Phase 1 data. The latter option would be difficult given the failed Phase 3 results in hand, Goodman said.

Satsuma is still reviewing the clinical trial data and the company says that it expects to provide more details on its business plans after completing the analysis. At the end of the second quarter of this year, Satsuma reported cash, cash equivalents, and marketable securities totaling $93.7 million.

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