RE: Cost-utility of talazoparib monotherapy treatment for locally advanced or metastatic breast cancer in Spain.

Dear Editor,

We read with interest the recent cost-utility analysis of talazoparib by de Labry Lima et al. [1]. We note the following limitations:

First, overall survival (OS) was based on the immature interim dataset [2] rather than the final dataset from EMBRACA trial (available at the time of publication) [3]. Specifically, the analysis chose a time horizon of 43 months; however, final OS showed a small proportion of patients receiving talazoparib survived beyond 60 months. Therefore, the selected time horizon was unable to fully capture the survival benefit of talazoparib. Second, the analysis only included conventional chemotherapies (capecitabine/eribulin/gemcitabine/vinorelbine) as subsequent treatments; however, it directly applied OS from EMBRACA that counted treatment effect of other subsequent treatments used in the trial. Treatment effect on OS adjusting for subsequent treatment was available at the time of publication [3]. The model should ensure the implemented OS data are aligned with the subsequent treatment modeled to give an unbiased estimate. Third, the study modeled utilities based on time to deterioration of EORTC QLQ-C30 global health status/QoL collected from EMBRACA trial [4]. However, it did not map the scales onto generic preference-based instruments, such as the EQ-5D, using appropriate mapping algorithms [5].

Funding: Pfizer.