In patients with unresectable stage IIIA/IIIB non-small cell lung cancer (NSCLC), local failure after chemoradiotherapy (CT-RT) often results in adverse outcomes and mortality. Targeted radiosensitization of the tumor could be an approach to improve local control. This study aims to evaluate the recommended phase 2 dose, dose-limiting toxic effects, and a maximally tolerated dose of nelfinavir mesylate, a protease inhibitor.

This open-label, single-group, single-institution, prospective phase 1/2 trial included a total of 35 patients aged 18-89 years with biopsy-confirmed unresectable stage IIIA/IIIB LA-NSCLC. The patients were randomly assigned to receive oral nelfinavir mesylate (635 mg twice daily or 1,250 mg twice daily). The primary outcomes of the study were graded toxic effects, overall survival, object response rate, and local & distant failure.

No dose-limiting toxic effects were reported during the trial. Furthermore, there were no grade 4 or higher nonhematologic toxic effects. Of 35 patients included in the trial, 33 had evaluable posttreatment computed tomographic scans, with an ORR of 94%. The median progression-free and overall survivals were 11.7 months and 41.1 months, respectively.

The research concluded that nelfinavir mesylate had an acceptable safety profile with no dose-limiting effects at all doses.