Praxis Precision Medicines Reports Positive Outcomes for Tremor Drug

Praxis Precision Medicines announced successful results from two pivotal studies of its essential tremor drug, ulixacaltamide, prompting plans to engage with the FDA regarding regulatory approval. Despite initial recommendations to halt the Phase 3 trials, the biotech firm persisted and reported significant improvements in patient outcomes, which could position ulixacaltamide as a potential blockbuster treatment for a condition currently lacking effective therapies.

Essential tremor, characterized by involuntary shaking in the arms and hands, affects approximately 7 million people in the United States. For many, the disorder also impacts head stability and speech. While existing treatments, such as older blood pressure medications and anti-seizure drugs, provide some relief, they come with limitations, including lack of efficacy and severe side effects. According to Marcio Souza, CEO of Praxis, “There’s no specific drug approved for essential tremor, and we’re here to change that.”

Ulixacaltamide is an oral small molecule designed to inhibit T-type calcium channels in the brain, which are linked to the abnormal neuronal firing associated with tremors. The drug, which is taken once daily, was evaluated in two Phase 3 studies. The first study involved 473 participants who were randomly assigned to receive either ulixacaltamide or a placebo for 12 weeks. Most participants were in their late 60s and had been living with essential tremor for approximately 30 years, with many experiencing worsening symptoms despite current treatments.

The primary objective of the first study was to assess patients using a composite scale measuring daily living tasks. Preliminary results indicated a 4.3-point improvement on this scale for those receiving the drug, compared to a 1.7-point change for the placebo group. Secondary objectives included tracking the rate of disease improvement, which also showed statistically significant results.

Interestingly, these findings stand in stark contrast to an interim analysis conducted earlier in the year. An independent data monitoring committee had recommended stopping the study for futility, suggesting that the existing data did not support the likelihood of success. However, Praxis opted to continue, believing that a small number of patient discontinuations may have skewed the committee’s conclusions.

In response to the committee’s concerns, Praxis updated the trial’s statistical analysis plan, shifting the main goal measure from day 84 to day 56, in consultation with the FDA. This adjustment, made without unblinding the data, allowed the company to return to the Phase 2 study that had established the primary goal and drug dosage. The results from day 56 now show statistically significant improvements, reinforcing the drug’s potential.

The second placebo-controlled study included 238 participants who received either ulixacaltamide or a placebo for eight weeks. Among those who responded to ulixacaltamide, 55% maintained their response after being switched to placebo for four weeks, compared to 33% of those who were directly withdrawn to placebo. The drug demonstrated a favorable safety profile with minimal adverse effects, primarily including constipation, dizziness, euphoric mood, and brain fog.

Praxis plans to present further data at upcoming medical conferences and in peer-reviewed journals. If discussions with the FDA proceed smoothly, the company anticipates submitting a new drug application in early 2026. While the pricing details remain undetermined, Souza indicated that for a condition impacting millions with limited treatment options, ulixacaltamide’s projected sales could reach the mid-to-high single-digit billions.

Following the disclosure of the data monitoring committee’s recommendation in March, Praxis’s stock price fell sharply. However, following the positive study results, shares surged to close at $162.71, reflecting an increase of over 183% from the previous day’s closing price. This surge positions Praxis to capitalize on its stock rise, as it lays the groundwork for a proposed public offering.