BioPharma

Acadia Pharmaceuticals drug flops in Phase III schizophrenia study

Nuplazid, which is FDA-approved for Parkinson's psychosis, failed to fully improve symptoms as an adjunctive treatment for schizophrenia.

A late-stage clinical trial of a drug under investigation for certain patients with schizophrenia who lack a Food and Drug Administration-approved therapy has failed.

San Diego-based Acadia Pharmaceuticals said Monday afternoon that its Phase III ENHANCE study of Nuplazid (pimavanserin), as an adjunctive treatment for schizophrenia patients with inadequate response to existing therapies, had failed to meet its primary endpoint of change in total positive and negative syndrome scale (PANSS) score over six weeks.

Shares of Acadia fell more than 13 percent on the Nasdaq when markets opened Tuesday morning following the news, having already fallen more than 12 percent in premarket trading.

Nuplazid was originally approved in April 2016 for hallucinations and delusions associated with Parkinson’s disease psychosis. The ENHANCE study was launched in November of the same year.

The company said Monday that adding Nuplazid showed a “consistent trend” in improvement of psychotic symptoms, but they did not show statistical significance on the PANSS total score. The company said a positive trend was also seen on the secondary endpoint of the clinical global impression-severity score, but that also did not achieve statistical significance. Positive symptoms of schizophrenia include the distorted thinking – such as delusions and hallucinations – usually associated with the disease. Negative symptoms include asociality, flat affect and poverty of speech.

On the other hand, when it broke down the analysis of the results by region, results on the primary and secondary endpoints were statistically significant, particularly in Europe, which accounted for more than 80 percent of patients.

In a note to investors Tuesday, Cowen analyst Subbu Nambi wrote that investors had extremely low expectations for the trial, given that physicians saw adjunct schizophrenia as a difficult indication for clinical trial success. She wrote that in a conference call with analysts following the results, it was stated that the discrepancy came from two factors. In particular, there was a low placebo and high drug response rate in Europe, while in the U.S. – which accounted for most of the remaining patients and has lately been a challenging place to do neuropsychiatric trials – the reverse was true.

Nambi also noted that despite the overall negative result, the PANSS negative symptom subscore did show a statistically significant improvement. She added that Cowen analysts see that as an encouraging read-through to the Phase II ADVANCE study, due to read out at the end of this year.

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