Large-scale genetic tumor profiling can identify increasing numbers of potentially actionable molecular variants for which approved anticancer drugs are available. In daily practice, however, when patients with such variants are treated with drugs outside of their approved label, successes and failures are not systematically collected or shared. Therefore, we initiated the Drug Rediscovery Protocol (DRUP), an innovative and adaptive precision oncology trial aimed at identifying signals of activity in cohorts of patients with defined tumor types and molecular variants, treated with anticancer drugs outside their approved label. Eligible patients have exhausted (or declined) standard therapies and have malignancies with potentially actionable variants for which no approved anticancer drugs are available. We use a stepwise approach per cohort of first 8 patients, and when at least one patient experienced clinical benefit that cohort expands to 24 patients. Presently, we have reviewed >1,100 submitted patient cases and included and treated >500 patients. We found an overall clinical benefit rate (defined as complete or partial response, or stable disease ≥16 weeks) of 29% although the formal analysis is per cohort. The potential of DRUP was illustrated by the identification of a successful cohort of patients with microsatellite instable tumors receiving nivolumab or durvalumab, and tumors with HRD treated with olaparib. Our results have led to a personalized reimbursement model for nivolumab in patients with MSI tumors that is supported by all regulatory parties. The DRUP hereby facilitates defined use of approved drugs beyond their label in (rare) cancer subgroups, identifies early signals of activity in these subgroups, accelerates clinical translation of new insights, and creates a publicly available knowledge-base for future decision making.

Citation Format: Emile E. Voest. The Drug Rediscovery Protocol: Getting the most out of approved drugs [abstract]. In: Proceedings of the AACR Special Conference on Advancing Precision Medicine Drug Development: Incorporation of Real-World Data and Other Novel Strategies; Jan 9-12, 2020; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(12_Suppl_1):Abstract nr IA19.