Key Pfizer Pipeline Drug Hits Setback, Potentially Delaying New RA Drug Competition
by Damien Conover | 25 Apr 11
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On April 21, Pfizer PFE reported one drug-related death in one of its Phase III trials (ORAL Sync) for rheumatoid arthritis (RA) drug tofacitinib. While we don't expect any changes to our fair value estimate for Pfizer based on the negative news, we believe the death will increase government scrutiny of the drug during the approval process. We're slightly lowering our expected probability of approval for the drug to 55% from 60%. Nevertheless, the death rate for the drug in clinical development is still in-line with other RA drugs currently approved. Additionally, given the severity of RA, we expect greater leniency from regulators. We project sales of tofacitinib to reach over $400 million by 2015. However, the increasingly negative side-effect profile for tofacitinib bodes well for other RA treatments including Abbott's ABT Humira. Tofacitinib's growing side effects had already included increased liver enzyme and cholesterol levels. The new patient death, combined with already known side effects, will likely delay the tofacitinib approval until late 2012 at the earliest. The complete data from the Phase III trial ORAL Sync will be available May 27, and additional Phase III tofacitinib trials should complete later this year.