Sotorasib Impresses in Patients With KRAS G12C–Mutant NSCLC

Bob T. Li, MD, PhD, MPH

Sotorasib (formerly AMG 510) demonstrated significant benefit in patients with KRAS G12C–mutated advanced non–small cell lung cancer (NSCLC) who progressed after standard treatment, according to results from the phase 2 portion of the CodeBreaK 100 trial (NCT03600883). The findings were presented at the International Association for the Study of Lung Cancer (IASLC) 2020 World Conference on Lung Cancer.^1,2

The agent induced a 6.8-month median progression-free survival (PFS) in patients. This represents the first KRAS G12C inhibitor to show PFS benefit in a phase 2 study, stated Amgen, the drug’s manufacturer.

Data also indicated that sotorasib led to a 37.1% confirmed objective response rate (ORR) and a disease control rate of 80.6% in this patient population at a median follow-up of 12.2 months. The median duration of response was 10 months.

“These results are encouraging and clinically meaningful for patients with advanced NSCLC harboring the KRAS G12C mutation,” said lead investigator Bob T. Li, MD, PhD, MPH, a medical oncologist at Memorial Sloan Kettering Cancer Center. “These are patients who have progressive disease after standard treatment, so they need additional treatments, and the fact that we are seeing rapid tumor shrinkages and durable responses in these patients is, for me, a step forward and a win for patients.”

In December 2020, the FDA granted a breakthrough therapy designation to sotorasib for use as a potential treatment in patients with KRAS G12C–mutated locally advanced or metastatic NSCLC, as determined via an FDA-approved test, after at least 1 prior systemic treatment.

Further, in February 2021, the FDA accepted a new drug application (NDA) for sotorasib and granted it a priority review for the treatment of patients with KRAS G12C–mutant locally advanced or metastatic non–small cell lung cancer NSCLC following at least 1 prior systemic treatment.

A prior phase 1 study demonstrated consistent findings with sotorasib in 35 previously treated patients with KRAS G12C–mutated advanced NSCLC.³ Data showed a 50% response rate in these patients; among 10 evaluable patients with NSCLC, 5 had a partial response (PR), with 4 confirmed PRs.

In the CodeBreaK 100 trial, patients were treated with oral sotorasib at 960 mg once daily. Eighty-one percent of patients had progressed on prior platinum-based chemotherapy and PD-1/PD-L1 inhibitors; the remain-der had progressed after having received 1 of these therapies. The data cutoff date was December 1, 2020.

According to additional findings, more than 80% of patients achieved disease control, including 3 complete responses and 43 PRs. The median best tumor shrinkage among all responders (n = 46) was 60%, and the median time to objective response was 1.4 months.

Results of exploratory analyses showed that the clinical activity to sotorasib was observed across a range of biomarker subgroups, including those with PD-L1–negative or –low status and those with ST K11 mutations. ST K11 mutations are generally linked with poorer outcomes in patients with NSCLC who have previously received treatment with checkpoint inhibitors and chemotherapy.

Regarding safety, sotorasib showed a favorable benefit-risk profile. The majority of treatment-related adverse events (TRAEs) were of grades 1 or 2, and no treatment-related deaths occurred. Grade 3 TRAEs occurred in 25 (19.8%) patients, and 1 patient (0.8%) reported a grade 4 TRAE. The most frequently reported all-grade TRAEs (any grade) were diarrhea (31.0%), nausea (19.0%), increased alanine aminotransferase (15.1%), and increased aspartate aminotransferase (15.1%). Treatment discontinuation rates due to TRAEs occurred in 7.1% of patients.

^REFERENCES

^{1. Li BT, Skoulidis F, Falchook G, et al. CodeBreaK 100: registrational phase 2 trial of sotorasib in KRAS G12C mutated non-small cell lung can-cer. Abstract presented at: IASLC 2020 World Conference on Lung Cancer; January 28-31, 2021; Virtual. Abstract PS01.07.}

^{2. Amgen’s investigational KRAS G12C inhibitor sotorasib demonstrated rapid, deep and durable responses in previously treated patients with ad-vanced non-small cell lung cancer. News release. PR Newswire. January 28, 2021. Accessed January 28, 2021. https://prn.to/3px7knl}

^{3. Fakih M, O’Neil B, Price TJ, et al. Phase 1 study evaluating the safe-ty, tolerability, pharmacokinetics (PK), and efficacy of AMG 510, a novel}