Supernus Pharmaceuticals' Depression Drug Candidate Faces Setback in Phase 2b Trial

Supernus Pharmaceuticals, a Maryland-based biopharmaceutical company, has announced disappointing results from a phase 2b clinical trial of its depression drug candidate, SPN-820. The study, which focused on patients with treatment-resistant depression (TRD), failed to meet its primary endpoint, casting doubt on the future of the program.

Trial Results and Implications

The randomized, placebo-controlled phase 2b study enrolled approximately 250 adult patients with TRD. Participants received either two or four 400-mg doses of SPN-820 orally every day. However, after four weeks of treatment, patients given SPN-820 showed no significant improvement in their Montgomery-Åsberg Depression Rating Scale scores compared to those given a placebo.

Jack Khattar, president and CEO of Supernus, expressed the company's disappointment in a statement: "We are disappointed that the trial did not meet its primary endpoint in this patient population. We will continue to analyze these data and discuss the future of the program with our development partner, Navitor Pharmaceuticals."

Despite the setback, the safety profile of SPN-820 remained consistent with prior trials, with few adverse events reported.

Background and Previous Findings

This latest trial result comes in stark contrast to earlier data presented by Supernus. In October, the company released results from a small trial involving 40 patients with major depressive disorder (MDD). That study showed SPN-820 improved symptoms at a level the biotech described as "clinically meaningful."

Following those initial positive results, Supernus had planned to decide which indication to pursue further—MDD, TRD, or both—after the phase 2b data in TRD became available. The recent trial failure has significantly narrowed the company's options for advancing the drug candidate.

Financial Impact and Future Outlook

The news of the trial failure had an immediate impact on Supernus Pharmaceuticals' stock, with shares dropping by 20% in after-hours trading on Tuesday night. This reaction reflects investor concern about the future of SPN-820 and its potential impact on the company's drug development pipeline.

Supernus originally licensed SPN-820, also known as NV-5138, from Navitor Pharmaceuticals in 2020. The licensing deal involved a $10 million fee and a $15 million investment, with potential total payments reaching up to $400 million if certain milestones were met.

As Supernus continues to analyze the trial data and consult with Navitor Pharmaceuticals, the pharmaceutical industry will be watching closely to see how this setback affects the company's strategy in the competitive field of depression treatment.