The first drug to target KRAS mutations in non-small cell lung cancer (NSCLC) has been approved by the US Food and Drug Administration.
KRAS mutations are the most common mutations to occur in NSCLC tumors, accounting for about 25% of them, but for a long time they appeared to be resistant to drug therapy.
The new drug, sotorasib (Lumakras), specifically targets the KRAS G12C mutation, which accounts for about 13% of NSCLC mutations.
It is considered to be something of a breakthrough in cancer research. When clinical data on the new drug (from 126 patients) were presented last year at the World Conference on Lung Cancer, lung cancer experts greeted the results enthusiastically, as reported by Medscape Medical News at the time.
“This is a historic milestone in lung cancer therapy. After four decades of scientific efforts in targeting KRAS, sotorasib has potential to be the first targeted treatment option for this patient population with a high unmet need,” Bob T. Li, MD, PhD, MPH, of Memorial Sloan Kettering Cancer Center in New York City, said at the time.
Now, in a press release from the manufacturer, Amgen, he said: “Sotorasib represents a major advancement in oncology and changes the treatment paradigm for patients with KRAS G12C-mutated non-small cell lung cancer.”
“Patients with non-small cell lung cancer who have progressed beyond first-line treatment face a poor prognosis and have limited treatment options available to them. Sotorasib delivers a new option for these patients, and it is the first KRAS-targeted therapy to be approved after nearly four decades of research,” he added.
Details of Clinical Data
This is an accelerated approval based on response rate data.
The FDA notes that the clinical data come from a study of 124 patients with locally advanced or metastatic KRAS G12C-mutated NSCLC with disease progression after receiving an immune checkpoint inhibitor and/or platinum-based chemotherapy.
The major outcome measured was overall response rate (ORR), which was 36%. Of the patients who responded, 58% had a duration of response of 6 months or longer.
Sotorasib was approved at a dose of 960 mg, and this dose was based on available clinical data as well as pharmacokinetic and pharmacodynamic modeling, the FDA noted. As part of the evaluation for this accelerated approval, the agency is requiring a postmarketing trial to investigate whether a lower dose will have a similar clinical effect.
The most common side effects include diarrhea, musculoskeletal pain, nausea, fatigue, liver damage, and cough. Sotorasib should not be used if patients develop symptoms of interstitial lung disease, and should be permanently discontinued if interstitial lung disease is confirmed.
Patients on sotorasib should have liver function tests prior to starting and while taking the drug; if liver damage develops, the drug should be stopped or the dose reduced. Patients should avoid taking acid-reducing agents, drugs that induce or are substrates for certain enzymes in the liver, and drugs that are substrates of P-glycoprotein (P-gp).
Companion Diagnostic Tests Also Approved
Along with the new drug, the FDA also approved two companion diagnostic tests — the QIAGEN therascreen KRAS RGQ PCR kit (approval granted to QIAGEN GmbH) for analyzing tumor tissue and the Guardant360 CDx (approval granted to Guardant Health, Inc) for analyzing plasma specimens to determine if the KRAS G12C mutation is present. The agency notes that if the plasma test comes back negative, the patient’s tumor tissue should be tested.