Seven months ago, independent clinical trial observers peeked at interim data for Praxis Precision Medicines’ essential tremor drug and recommended stopping the Phase 3 studies. Praxis kept going. On Thursday, the biotech reported successful results that have the company preparing to talk to the FDA about a submission seeking regulatory approval of a drug projected to become a blockbuster seller several times over.
Essential tremor leads to involuntary shaking and trembling in the arms and hands. For some patients, the disorder affects the head and the ability to speak. According to Boston-based Praxis, an estimated 7 million people in the U.S. live with essential tremor, a disorder whose cause is not known. There are currently no drugs specifically approved for essential tremor, though older blood pressure medications and anti-seizure products are used to manage the condition. Lack of efficacy and severe side effects lead many patients to stop taking these drugs, Praxis CEO Marcio Souza said during a Thursday morning conference call.
“There’s no specific drug approved for essential tremor and we’re here to change that,” he said.
Could QuantalX’s Device Make Managing Brain Health Easier?
CEO and neuroscientist Dr. Iftach Dolev on how the new device can bring a powerful tool to psychiatrists and neurologists alike.
Ulixacaltamide is an oral small molecule designed to selectively inhibit T-type calcium channels in the brain, an approach intended to block the abnormal bursts of neuronal firing correlated with tremors. The drug came from Praxis’s platform technology for discovering small molecules with potential to address central nervous system disorders.
Praxis evaluated ulixacaltamide, a once-daily pill, in two Phase 3 studies. The first study randomly assigned 473 participants to receive either the study drug or a placebo for 12 weeks. Most of these patients were in their late 60s and had experienced essential tremor for about 30 years. For many of trial participants, symptoms had worsened over the past three years despite taking available medications. The main study goal was assessing patients according to a composite scale that measures the ability to perform tasks of daily living. The preliminary results reported Thursday show a 4.3 point improvement on this scale compared to a 1.7 point change for the placebo arm. Secondary goals included measuring the rate of disease improvement.
While the preliminary results achieved statistical significance on the primary and secondary trial goals, they stand in contrast to a planned interim analysis earlier this year. In February, an independent data monitoring committee looked at the data up to that point and concluded the study was unlikely to succeed under parameters set by the study’s statistical model. While the committee encouraged Praxis to explore alternative analysis methods, it also recommended stopping the study for futility. No details of the data were disclosed from the study, which remained blinded.
When Praxis announced the committee recommendation in March, both Phase 3 studies were nearly fully enrolled, so Praxis decided to continue them. As for the committee’s recommendation, Souza said it came at a point where a few patient discontinuations in what was then a small sample size may have contributed to the committee’s futility finding.
5 High-Impact Tax Strategies Every Physician Should Use in 2026 to Reduce Their Tax Bill
AI-native tax firm Gelt combines top human tax experts with AI to help physicians and healthcare practices use data-driven tax strategies to lower liabilities, improve profitability, and future-proof their finances.
Last month, Praxis updated the trial’s statistical analysis plan, changing the main goal measure from day 84 to day 56. This change was made in consultation with the FDA and without any unblinding or analysis of the trial data. Souza explained the company decided the most prudent approach was to refer back to the Phase 2 study that established the main goal and drug dose for the pivotal clinical trials. This study evaluated ulixacaltamide over 56 days. The unblinded Phase 3 results now show statistically significant measures at this time point. Souza added that even without the change, the trial is successful. Thursday’s data readout includes day 84 results, which continue to show statistically significant improvement.
“It really doesn’t matter, in a sense,” Souza said. “The trial is positive independently of how it’s analyzed on the timepoint of [day] 56 or 84.”
Praxis also reported results from the second placebo-controlled study, which enrolled 238 participants randomly assigned to receive a placebo or ulixacaltamide for eight weeks. Of the 80 responders to ulixacaltamide, half were randomly withdrawn from the study drug and switched to placebo for four weeks. On the main goal measuring maintenance of response to the experimental therapy, Praxis said 55% of participants in this study maintained a response compared to 33% of those withdrawn to a placebo.
Ulixacaltamide was safe and well tolerated with no reports of drug-related serious adverse effects. The main side effects included constipation, dizziness, euphoric mood, and brain fog. Praxis said it plans to share more data from these studies at upcoming medical conferences and in peer-reviewed publications. If discussions with the FDA go well, Praxis anticipates submitting a new drug application in early 2026.
It’s early to talk about drug pricing and Souza would not offer specific sales projections for the drug. Even so, he said that for a disease that affects several million Americans who currently have no effective treatments, the low-end of Praxis’s estimates for ulixacaltamide sales is in the mid-to-high single digit billions of dollars.
[Paragraph updated with stock offering details.] After Praxis disclosed the data committee’s futility recommendation in March, Praxis’s stock price tanked. On Thursday, shares of the company soared and closed the day at $162.71, up more than 183% from Wednesday’s closing price. The company is capitalizing on the stock price rise by laying the groundwork for a proposed public offering. Thursday night, Praxis priced a $525 million stock offering. In the prospectus, the company says it plans to apply the proceeds toward continued R&D and potential commercialization of late-stage assets.
Public domain image by Flickr user SciTechTrend