Alkermes Announces Positive Preliminary Phase 3 Results for Schizophrenia Drug

Alkermes announced positive preliminary topline results from ENLIGHTEN-1, the first of two key phase 3 studies in the ENLIGHTEN clinical development program for ALKS 3831, an investigational, novel, once-daily, oral atypical antipsychotic drug candidate for the treatment of schizophrenia. ENLIGHTEN-1 was a multinational, double-blind, randomized, phase 3 study that evaluated the antipsychotic efficacy, safety and tolerability of ALKS 3831 compared to placebo over four weeks in 403 patients experiencing an acute exacerbation of schizophrenia. The study also included a comparator arm of olanzapine, an established atypical antipsychotic agent with proven efficacy. The study met the prespecified primary endpoint, with ALKS 3831 demonstrating statistically significant reductions from baseline in Positive and Negative Syndrome Scale (PANSS) scores compared to placebo (p<0.001). Data from the study also showed that olanzapine achieved similar improvements from baseline PANSS scores, compared to placebo (p=0.004). The study also met its key secondary endpoint of improvement on the Clinical Global Impression – Severity (CGI-S) scale for ALKS 3831 versus placebo (p=0.002). ALKS 3831 is designed to provide the strong antipsychotic efficacy of olanzapine and a differentiated safety profile with favorable weight and metabolic properties.

“The positive results of ENLIGHTEN-1 provide clear evidence of the safety, tolerability and antipsychotic efficacy of ALKS 3831 in a large, randomized registration trial,” said Elliot Ehrich, M.D., Executive Vice President of Research and Development at Alkermes. “The results of this phase 3 study also provide additional evidence of the antipsychotic properties of ALKS 3831 relative to olanzapine, an agent well known to clinicians. We look forward to completing our analysis of this large study and presenting the data at a future medical meeting.”

“Many physicians recognize the powerful efficacy profile of olanzapine, but are hesitant to prescribe it given the severe weight gain and metabolic side effects commonly associated with its use,” said Christoph Correll, M.D., Professor of Psychiatry and Molecular Medicine at Hofstra Northwell School of Medicine. “A new antipsychotic with robust efficacy and a favorable weight and metabolic profile compared to olanzapine would be a welcome addition to the schizophrenia treatment landscape. This study confirms a key element of this profile, with a clear demonstration of efficacy in a large, well-conducted clinical trial.”

Overall, 91% of patients who received ALKS 3831 completed the study, compared to 89% of patients who received olanzapine and 83% of patients who received placebo. The most common adverse events for both the ALKS 3831 and olanzapine treatment groups were weight gain, somnolence and dry mouth.

Alkermes will present comprehensive data from the ENLIGHTEN-1 study at an upcoming medical meeting and submit the results for publication in a peer-reviewed journal. ENLIGHTEN-2, a six-month phase 3 study evaluating the weight gain profile of olanzapine compared to ALKS 3831, is ongoing with data expected in 2018.