Bristol-Myers/Otsuka: Abilify Receives Priority Review for MDD

BMS and Otsuka are seeking an additional indication for Abilify having conducted trials evaluating the adjunctive use of the atypical antipsychotic drug for adults with major depressive disorder. Although this is a step forward for the development of this drug class in depression, clinical data is still needed to demonstrate the efficacy of an atypical antipsychotic as a monotherapy.

Positive data was shown in two six-week, double-blind, randomized, placebo-controlled, multi-center trials evaluating the adjunctive use of Abilify in over 700 adult patients with major depressive disorder (MDD) who had an inadequate response to monotherapy with one or more antidepressant therapies. These results have led to the FDA not only accepting Bristol-Myers Squibb and Otsuka’s application, but also indicating that it will be given a priority review with the goal for reviewing the drug within six months.

Depression is typically treated with antidepressants such as Eli Lilly’s selective serotonin reuptake inhibitor Prozac (fluoxetine). However, many patients respond inadequately or suffer from comorbidities such as agitation or anxiety. Atypical antipsychotics, drugs primarily used to treat schizophrenia, have increasingly been used to treat refractory depression patients and specific depression comorbidities.

With modern classes of antidepressants now highly genericized and saturated with reformulations, market players are turning their attention to expanding atypical antipsychotic use in this indication. In comparison to the antidepressant class of drug, the atypical antipsychotics are largely patent protected and command a far higher price premium.

Datamonitor believes that positive clinical trial data for Abilify use in depression as an adjunctive therapy is a positive step forward. However, with a large volume of off-label prescribing already occurring, and a positive historical trend in sales, this news is unlikely to significantly boost sales of the drug class as a whole.

Demonstration of efficacy against depression symptoms as a monotherapy will be a more significant evolution. Therefore, Datamonitor forecasts that sales of the atypical antipsychotics in depression will be more significantly stimulated by anticipated positive clinical trial data investigating the use of Seroquel (quetiapine) monotherapy in this indication. Datamonitor forecasts peak MDD-specific seven major market sales of $1.43 billion in 2008 for the entire atypical antipsychotic class, followed by a decline due to competition from pipeline drugs and generics.