Acadia Pharmaceuticals Inc. recently released top-line results from the Phase 3 ADVANCE-2 trial evaluating pimavanserin for negative symptoms of schizophrenia. Unfortunately, the results did not demonstrate a statistically significant improvement over placebo on the study’s primary endpoint, the change from baseline to week 26 on the Negative Symptom Assessment-16 (NSA-16) total score.
Steve Davis, Acadia’s Chief Executive Officer, stated, “We will continue to analyze these data with our scientific advisors, but we do not intend to conduct any further clinical trials with pimavanserin. We want to thank the patients, their families, and the investigators for their contributions in this important study.”
The ADVANCE-2 trial used the NSA-16 scale, which is designed to measure change in the wide range of predominant negative symptoms that patients experience. This scale looks at 16 items in five subscales and covers symptoms such as blunted affect, poor socialization, and lack of motivation.
Although the change from baseline observed in the pimavanserin arm of ADVANCE-2 was similar to that observed in the 34 milligram dose in ADVANCE-1, the placebo effect in ADVANCE-2 was higher than in ADVANCE-1.
Despite the disappointing results from the trial, the safety and tolerability profile of pimavanserin remained consistent with previous clinical trials, showing a low rate of adverse events. In ADVANCE-2, pimavanserin was well-tolerated with an adverse event rate of 30.4% compared to 40.3% for the placebo arm.
Pimavanserin is already marketed as Nuplazid, the first and only prescription medication approved by the FDA for the treatment of hallucinations and delusions associated with Parkinson’s disease psychosis. In the fourth quarter of 2023, Nuplazid’s net product sales were $143.9 million, and $549.2 million for fiscal year 2023.
Following the release of these results, ACAD shares are down 14.63% at $20.60 during the premarket session. It will be interesting to see how Acadia Pharmaceuticals moves forward in light of these findings and the impact they may have on the company’s future developments in the field of schizophrenia treatment.
