Randomized phase II trial comparing molecularly targeted therapy based on tumor molecular profiling versus conventional therapy in patients with refractory cancer: cross-over analysis from the SHIVA trial

Background Several studies used the ratio of progression-free survival (PFS) on genotype-matched treatment to PFS on genotype-unmatched treatment to assess the efficacy of therapy guided by patients' tumor molecular profiling. We evaluated the PFS ratio from patients who cross-over in the SHIVA trial. Patients and methods The primary end point of the SHIVA trial was to compare PFS on molecularly targeted agents (MTAs) based on tumor molecular profiling and treatment at physician's choice (TPC) in patients with any kind of cancer who had failed standard-of-care therapy. The experimental treatment included only marketed MTAs given outside their indications according to a pre-specified treatment algorithm. Patients were allowed to cross-over at disease progression in both arms. Response was evaluated according to RECIST 1.1 at randomization and at cross-over. We evaluated the ratio of PFS on MTA (PFSMTA) to PFS on TPC (PFSTPC) in patients who crossed-over. Results Among 741 patients enrolled in the SHIVA trial, 197 were randomized, and 95 crossed-over, including 70 patients from the TPC to the MTA arm and 25 patients from the MTA to the TPC arm. Two patients crossed-over in the TPC arm without disease progression. The PFSMTA/PFSTPC ratio exceeded 1.3 in 37% of patients who crossed-over from the TPC to the MTA arm. The PFSMTA/PFSTPC ratio exceeded 1.3 in 61% of patients who crossed-over from the MTA arm to the TPC arm. Conclusions The cross-over analysis of the SHIVA trial identified 37% of patients who crossed-over from TPC to MTA with a PFSMTA/PFSTPC ratio exceeding 1.3.