The Pink Sheet
“Schering Plough’s Saphris Gets Strong Nod From FDA Panel”
July 31, 2009
The atypical antipsychotic market should soon be seeing competition from a new entry with a novel formulation and a more attractive safety profile, after an FDA advisory committee voted strongly in favor of Schering Plough’s Saphris (asenapine) for acute schizophrenia and bipolar mania in adults at a July 30 meeting.
The Psychopharmacologic Drugs Advisory Committee found asenapine to be similarly efficacious to others in the atypical antipsychotic class and have a slightly better safety profile. The FDA panel voted unanimously that the risk-benefit balance was positive for the bipolar indication, and 9-1 with 2 abstentions that the balance was positive for schizophrenia.
They sited similar efficacy to other antipsychotics, a slightly better safety profile, the need for further treatment options for the difficult-to-treat patient populations, and the benefit of asenapine’s formulation as a sublingual tablet for patients that have trouble swallowing pills.
The sponsor did not come into the meeting facing an uphill battle. In briefing documents released prior to the meeting FDA stated its support for the safety and efficacy of asenapine compared to rest of the atypical class. And breaking with typical advisory committee protocol, the agency did not even make its own presentation of the data, instead saying it supported the sponsor’s conclusions
For the risk side of the equation in both indications, asenapine made a strong showing against a class of atypical antipsychotics known for a host of safety and tolerability issues.
Asenapine was not associated with any new or unexpected adverse events, and even demonstrated less impact on weight and metabolic parameters than some of its would-be competitors, including Lilly’s Zyprexa (olanzapine) and Johnson & Johnson’s Risperdal (risperidone), both of which served as active controls in the development program.
In terms of efficacy, the panel found it easier to vote on the bipolar indication than schizophrenia, voting unanimously that the bipolar studies were clearly positive for asenapine.
The primary concern pertaining to asenapine in bipolar disorder pertained to dose, and whether the drug could be efficacious at the 10 mg BID dose at which it was studied. Schering told the panel it is committed to conducting a postmarket study of asenapine at 5 mg BID for bipolar disorder.
Votes on the schizophrenia indication were a bit more scattered due to some confusion of how to interpret the overall efficacy signal over four trials. Two of the trials were positive for asenapine, but only one was positive for the dose the firm is proposing: 5 mg BID. The other trial tested asenapine at 10 mg BID, showing similar but no additional benefit to the 5 mg dose.
Of the other two trials, one was discounted as a failed study (showing no benefit for either asenapine or the active control against placebo) and the other was negative (with the active control, but not asenapine, superior to placebo).
Ultimately, they voted 10-2 that asenapine was effective for schizophrenia, comparable to other atypical antipsychotics. The two members who voted against approval cited concerns about the mixed signals across the trials, and the 60 percent drop-out rate in one of the trials (an attrition rate FDA said was typical for psychiatric trials).
The panel also voted 10-2 that the safety profile for the schizophrenia indication was acceptable, after determining that a vote against efficacy must logically lead to a vote against safety, despite a risk profile positive in comparison to others in the class.
In addition to the lower-dose study of asenapine in bipolar disorder, Schering assured the panel that it is also committed to conducting post-market pediatric studies for both indications.