Biovail Corporation (NYSE/TSX: BVF) today commented on a proposed
clinical trial recently announced by Teva Pharmaceutical Industries Ltd.
According to Teva, the trial is intended to address reports of
inefficacy and adverse events by consumers who switched from Wellbutrin
XL® 300 mg, Biovail’s FDA-approved brand of the
antidepressant, bupropion hydrochloride, to Budeprion XL, Teva’s generic
formulation of the drug. The trial was described in a Dow Jones Newswire
article dated December 2, 2009.
“Even if Wellbutrin XL®
and Budeprion XL were found (again) to be bioequivalent according to FDA
bioequivalence criteria, the failure to find systematic differences in
AUC and Cmax in the study does not exclude the possibility of
other between-product differences affecting clinical response.”
Based on the limited information that has been made available about the
clinical trial by Teva, Biovail believes the proposed study will not
likely effectively address the complaints of consumers because it is too
small in size and too brief in duration.
According to the December 2, 2009 article, the proposed study will
enroll 138 patients who complained after switching from Wellbutrin XL®
300 mg to Budeprion XL. The study purportedly will employ a “double
dummy” design in which patients will receive both placebo and active
doses of each product over 16 days, alternating after eight days.
Patients will be confined in a clinical setting for a total period of 24
days.
A statement in the article attributed to Teva’s head of regulatory
affairs suggests that the study will rely on blood-level data to verify
bioequivalence of Wellbutrin XL® and Budeprion XL. The
article indicates that bioequivalence will be based on the standard
statistical criteria of the U.S. Food and Drug Administration (FDA).
Adverse events are also to be recorded.
Budeprion XL is already deemed to be bioequivalent to Wellbutrin XL®
by the FDA as defined by existing standard FDA criteria. Biovail
believes this determination is likely to be confirmed by the proposed
new trial.
However, based on available information, an independent expert retained
by Biovail to consider the matter noted, “Even if Wellbutrin XL®
and Budeprion XL were found (again) to be bioequivalent according to FDA
bioequivalence criteria, the failure to find systematic differences in
AUC and Cmax in the study does not exclude the possibility of
other between-product differences affecting clinical response.”