New high for Alkermes on Phase II schizophrenia data

Alkermes plc (NASDAQ:ALKS) hit a 52-week high on Wednesday, jumping $5.82 (10%) to $66.75 after its ALKS 3831, a combination of olanzapine plus samidorphan, met the primary endpoint of equivalence to olanzapine in reducing Positive and Negative Syndrome Scale (PANSS) scores from baseline to 12 weeks in a Phase II trial to treat schizophrenia.

Olanzapine is an approved antipsychotic monoaminergic receptor antagonist whose label carries a warning for weight gain. Alkermes' 309-patient trial tested the ability of samidorphan, a mu opioid receptor ( OPRM1; MOR) antagonist, to reduce weight gain caused by olanzapine alone. Indeed, the ALKS 3831 combination led to a 37% lower mean weight gain at 12 weeks vs. olanzapine plus placebo (p=0.006). The study design included a one-week lead-in on olanzapine followed by 12 weeks of either ALKS 3831 or olanzapine. In a pre-specified subpopulation who gained weight during the lead-in, ALKS 3831 led to a 51% lower mean weight gain at 12 weeks (p<0.001). ...