Real-World Analysis of Off-Label Use of Molecularly Targeted Therapy in a Large Academic Medical Center Cohort

Abstract

PURPOSE The primary objective of this study is to quantify the use of off-label molecularly targeted therapy and describe the clinical situations in which off-label targeted therapy are used. A key secondary objective is to report the outcomes of patients treated with off-label use of targeted therapy. PATIENTS AND METHODS We searched the electronic health record between 2000 and 2020 at our center to characterize the volume, clinical settings, and outcomes associated with off-label use of targeted therapies in different types of solid tumors. RESULTS Among 46,712 patients who received targeted therapies, we identified 119 instances of off-label use of targeted therapy. Colon cancer was the most common cancer type to receive off-label targeted therapy in 18 patients (15.1%), followed by 13 with non–small-cell lung cancer (10.9%), eight with cholangiocarcinoma (6.7%), and seven with glioblastoma (5.9%). The most frequent molecular rationale for off-label therapy came from a comprehensive next-generation sequencing test (53.7%). The most frequently mutated gene that provided the rationale for targeted therapy was BRAF (20.1%), with BRAFV600E being the most common molecular alteration overall (15.1%). The median duration of off-label targeted therapy was 3.58 months, and the overall survival of treated patients was 7.59 months. There were 37 patients (31.1%) treated for longer than 6 months, 23 patients (19.3%) who survived ≥ 2 years, and 13 patients who were still on therapy as of June 2020. CONCLUSION In this large cohort study of patients with solid tumors, off-label use of targeted therapy was uncommon. With that said, a notable proportion of patients had treatment durations ≥ 6 months and survivals of ≥ 2 years.