Another KRAS G12C inhibitor. Congrats to FCS Director of Drug Development Manish Patel, MD, one of the authors. Durable responses with less adverse events.
Divarasib (GDC-6036) is a covalent KRAS G12C inhibitor that was designed to have high potency and selectivity.
In a phase 1 study, we evaluated divarasib administered orally once daily (at doses ranging from 50 to 400 mg) in patients who had advanced or metastatic solid tumors that harbor a KRAS G12C mutation. The primary objective was an assessment of safety; pharmacokinetics, investigator-evaluated antitumor activity, and biomarkers of response and resistance were also assessed.
A total of 137 patients (60 with non–small-cell lung cancer [NSCLC], 55 with colorectal cancer, and 22 with other solid tumors) received divarasib. No dose-limiting toxic effects or treatment-related deaths were reported. Treatment-related adverse events occurred in 127 patients (93%); grade 3 events occurred in 15 patients (11%) and a grade 4 event in 1 patient (1%). Treatment-related adverse events resulted in a dose reduction in 19 patients (14%) and discontinuation of treatment in 4 patients (3%). Among patients with NSCLC, a confirmed response was observed in 53.4% of patients (95% confidence interval [CI], 39.9 to 66.7), and the median progression-free survival was 13.1 months (95% CI, 8.8 to could not be estimated). Among patients with colorectal cancer, a confirmed response was observed in 29.1% of patients (95% CI, 17.6 to 42.9), and the median progression-free survival was 5.6 months (95% CI, 4.1 to 8.2). Responses were also observed in patients with other solid tumors. Serial assessment of circulating tumor DNA showed declines in KRAS G12C variant allele frequency associated with response and identified genomic alterations that may confer resistance to divarasib.
Treatment with divarasib resulted in durable clinical responses across KRAS G12C–positive tumors, with mostly low-grade adverse events. (Funded by Genentech; ClinicalTrials.gov number, NCT04449874. opens in new tab.)
Superior to osi (23 vs 16 progression-free survival). This is more toxic though, but seems manageable. Could this be a new first line standard of care? Also, this includes brain penetration data.
Adding SBRT improves local control and disease progression in the brain but not overall survival. Do the radiation oncologists have input? Is it worth it to control symptoms?
Neoadjuvant Osimertinib did not have a significant impact on major pathologic response and there were no ypCR’s after a median of ~8 weeks of therapy. I do think this shows a measurable response, enough such that I would consider Osi in a patient with “borderline resectable” disease.
Osimertinib in adjuvant, now after chemotherapy and radiation, next… Neoadjuvant??? Trials are ongoing.
This is here till progression.
Failed? Numerical overall survival (OS) benefit for sacituzumab vs docetaxol, but not statistically significant. Better tolerated, also overall survival (OS) noticed more in patients who did not respond to antiPDL-1 therapy.
FCS Hematology Oncology Review creates a platform for our physician network to observe the most recent articles and studies available in the oncology and hematology world. By sharing these articles we are building our wealth of knowledge of new observations and treatments as they come available.
