Formal Consensus Method to Evaluate the Conformity of Prescription of a Recently Approved Chemotherapy Treatment in an Observatory Study

Cabazitaxel is a second line chemotherapy drug recently approved for the treatment of metastatic castration-resistant prostate cancer. A first panel of French experts and a second independent panel of European experts were convened to assess the conformity of prescription of cabazitaxel with a Delphi consensus method. A two-round modified Delphi consensus process was conducted. This methodology is based on experts' opinion obtained in a systematic manner. The process was divided into five steps: (i) elaboration of the questionnaire, (ii) rating, (iii) analysis, (iv) discussion of the points with absence of consensus following rating of the questionnaire, and (v) final reporting. Consensus was defined according to RAND method and all analyses were conducted according to the same methodology. At the end of the two rounds of rating and a synthesis meeting, of the 26 items included in the Summary of Product Characteristics (SPC), 11 items were judged appropriate with strong consensus by the two independent panels of experts. These items can therefore be considered of prime importance to evaluate conformity of cabazitaxel prescription in the context of observatory studies as well as in further clinical trials using this new taxane. Our findings further provide important evidence about the value of the Delphi consensus and highlight a requirement for "conformity" standards to assist practitioners in a safe chemotherapy drug prescription.