Generic and Branded Docetaxel.

Abstract

We thank Leveque et al for their thoughtful comments regarding our study comparing generic and branded formulations of docetaxel. We agree that the generic formulations are expected to be comparable to the branded drugs in terms of quality and clinical activity. However, several studies have raised the concern about clinically significant differences between generic and branded formulations with both chemotherapy and nonchemotherapy products.1–4 Furthermore, the differences between brand and generic formulations of docetaxel were previously addressed and were attributed to insufficient active ingredients and/or high level of impurities that may affect the efficacy and safety of the drug.5,6 Poirier et al compared the adverse event profile of generic docetaxel to the branded product and reported results that were consistent with those reported in our study. The incidence of febrile neutropenia was more serious with generic docetaxel despite increased G-CSF use.5 We agree that the presence or absence of drug– drug interactions in the study patients may have had an impact on the findings, and we agree that the unavailability of this information for the patients included is a limitation to the study. However, we predict that the large sample size and the similarities between the groups in several patient-related characteristics may haveminimized the impact of this limitation on the final results. The findings of this study and other similar studies are important for clinicians when they switch patients from branded to generic formulations or vice versa. In fact, our study was conducted as a result of the clinical observations reported to the pharmacy after patients had been switched from the branded docetaxel to the generic. The studywas generated to answer the question of whether the change in docetaxel formulation was associated with the observed increased incidence of febrile neutropenia.