Posted: Friday, October 7, 2022
On October 3, Calithera Biosciences announced that the U.S. Food and Drug Administration (FDA) has granted Fast Track designation to its investigational mTORC1/2 inhibitor sapanisertib (CB-228) for the treatment of adults with unresectable or metastatic squamous non–small cell lung cancer (NSCLC) that harbors a mutation in NRF2. Eligible patients have received prior platinum-based chemotherapy and immune checkpoint inhibitor therapy.
NRF2 mutations are found across multiple solid tumors, with these mutations occurring in approximately 15% of patients with squamous NSCLC. Sapanisertib targets a survival mechanism in NRF2-mutated tumor cells.
A recent investigator-initiated, multicenter, open-label phase II trial (ClinicalTrials.gov identifier NCT05275673) is evaluating sapanisertib monotherapy in patients with NRF2-mutated squamous NSCLC whose disease has progressed on or after platinum-doublet chemotherapy and immune checkpoint inhibitor therapy (anti–PD-L1) with or without anti–CTLA-4. Sapanisertib is being given in a dose schedule of 2 mg twice a day or 3 mg once a day in those with either wild-type or mutated NRF2, as detected by next-generation sequencing.
According to the manufacturer, use of sapanisertib has been well tolerated and demonstrated single-agent activity. The confirmed overall response rate in the phase II trial was 27% (3 of 11 patients), and median progression-free survival was 8.9 months (95% confidence interval = 7 months to not reached) in heavily pretreated patients with NRF2-mutated squamous NSCLC.