Positive Topline Phase 2 Results for Novel Schizophrenia Drug

Megan Brooks

January 07, 2015

Topline results from a phase 2 study show that treatment with a novel oral antipsychotic was as effective as treatment with the antipsychotic olanzapine (multiple brands) with far less weight gain in patients with schizophrenia, the company developing the drug announced today.

The drug currently known as ALKS 3831, from Alkermes, combines samidorphan, a novel, potent mu-opioid antagonist, with olanzapine.

"ALKS 3831 is designed to attenuate olanzapine-induced metabolic side effects, including weight gain, in patients with schizophrenia and to have utility in the treatment of schizophrenia in patients with alcohol use," the company explained in a news release.

In the 300-patient phase 2 study, ALKS 3831 achieved the study's primary efficacy endpoint by demonstrating equivalence to olanzapine in reducing total scores on the Positive and Negative Syndrome Scale at week 12.

ALKS 3831 also met the principal prespecified secondary endpoint of the study by demonstrating a 37% lower average weight gain compared with olanzapine in the full study population (P = .006), and a 51% lower average weight gain compared with olanzapine in a subset of patients who gained weight in the 1-week olanzapine lead-in period (P < .001).

"Olanzapine is considered one of the most efficacious atypical antipsychotics, yet it has one of the highest incidences and greatest amounts of weight gain among the widely prescribed products in this class of drugs, severely limiting its clinical use," Peter Weiden, MD, professor of psychiatry at the University of Illinois Medical Center, in Chicago, said in the release.

"This study showed very promising results for ALKS 3831 in addressing the major drawback of weight gain in patients treated with olanzapine, and it offers the potential for widening the therapeutic use of an olanzapine agent to meet the needs of patients," Dr Weiden added.

ALKS 3831 was generally well tolerated. Rates of discontinuation due adverse events were low and were similar to that with olanzapine, the company said. The most common adverse events seen with ALKS 3831 were somnolence, sedation, and dizziness.

Alkermes plans to present comprehensive safety and efficacy data from the phase 2 study at an upcoming medical meeting and to submit the results for publication in a peer-reviewed journal.

Patients who completed the 12-week phase 2 study were eligible to continue in an extension phase and receive one of the three doses of ALKS 3831 for an additional 12 weeks. "This 12-week extension is currently ongoing, and data to date indicate the durability of ALKS 3831's effect on weight. Complete results from the second 12-week extension stage are expected in the second quarter of 2015," the company said.

Schizophrenia affects an estimated 2.4 million Americans.


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