Examining crossover and postprotocol therapies in first-line immunotherapy trials in non-small cell lung cancer

Immune checkpoint inhibitor (ICI) therapy has led to significant improvement in outcomes for patients with nononcogene-driven advanced non-small cell lung cancer (NSCLC). The rate of crossover and receipt of postprotocol ICI in frontline trials for advanced NSCLC has not been systematically evaluated.

ClinicalTrials.gov was used to identify phase 3 studies evaluating the use of immunotherapy or combination chemoimmunotherapy against chemotherapy alone in the frontline management of advanced NSCLC. Data on outcomes, rate of crossover and/or subsequent post-protocol receipt of immunotherapy, and the start dates of these clinical trials were then extracted.

Twenty-three frontline trials in nononcogene-driven advanced NSCLC were identified. Six trials with ICI monotherapy/dual ICI therapy and 17 trials evaluating chemotherapy/ICI in first-line advanced NSCLC were included in the analysis. The crossover rate ranged 0% to 54% in ICI monotherapy/dual ICI trials and 0% to 52% in chemotherapy/ICI trials. Nineteen of 23 trials provided information on subsequent postprotocol therapies. Among the trials not allowing crossover, postprotocol ICI was administered to 17% to 45.8% of patients. Information regarding the eventual receipt of ICI therapy was available for 22 of 23 trials. Of 6631 patients, 2507 (37.8%) randomized to the control arm eventually received ICI therapy.

The rate of crossover and postprotocol ICI use was low in frontline trials for first-line NSCLC incorporating ICI. Given the proven improved overall survival of ICI in a broad population, there is a need to ensure availability of this life-prolonging therapy in future trials, either by crossover treatment or postprotocol administration.