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.)
Osimertinib resulted in a significant progression-free survival benefit as compared with placebo: the median progression-free survival was 39.1 months with osimertinib versus 5.6 months with placebo in the EGFR mutated patients. Osmiertinib shows efficacy in patients with EGFR mutation who underwent curative surgery or chemoradiotherapy.
Another possible option for first line NSCLC EGFR mutated (non-exon 20) is Osimertinib (osi). Osi and chemotherapy had less brain metastases. And with Amivantamab and Lazertinib (EGFR inhibitor), the combination had better PFS and OS (HR0.8). Higher toxicity though with 10% discontinuation vs 3% for Osimertinib. This is interim analysis, toxicity was EGFR related mostly.
Perioperative nivolumab (Nivo) showed a 20% 18-month EFPS improvement. This is another option to consider for your patients with stage IIA-IIIB NSCLC. Of note, the study arm received chemo + Nivo x 4 cycles preoperatively, then 12 months of Nivo therapy, and toxicities were as expected.
FCS medical oncologist and hematologist Ernesto Bustinza-Linares, MD has co-authored an abstract published in the American Society of Clinical Oncology Journal, JCO Precision Oncology, that uncovers a new testing method to determine personalized care options for patients with metastatic non-small cell lung cancer (NSCLC). The abstract’s authors address the limitations of existing guidelines that recommend checkpoint immunotherapy, sometimes in combination with chemotherapy, for treating NSCLC, which often discounts patient variability and immune factors. The findings from the study show that by incorporating additional plasma proteome-based testing, combined with the standard protein inhibitor testing, clear differences in patient outcomes were observed after applying targeted treatments based on the testing results.
Less maintenance is NOT NON-inferior, so it is inferior in patients with wild type BRAF metastatic colon cancer. So it is better to keep on the full regimen. Although, quality of life is better.
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.
