Amgen has announced that the Phase II cohort of the CodeBreaK 100 clinical study of its investigational drug, sotorasib (AMG 510), in patients with KRAS G12C-mutated advanced non-small cell lung cancer (NSCLC) demonstrated durable responses.

Sotorasib is an investigational KRAS inhibitor which is being studied in the broadest clinical programme investigating ten combinations with sites across five continents.

For CodeBreaK 100, the Phase I and II, first-in-human, open-label multicentre study, patients with KRAS G12C-mutant solid tumours, who have received a prior line of systemic anticancer therapy, were enrolled.

The Phase II trial in NSCLC enrolled 126 patients, of which 124 had centrally evaluable lesions by RECIST at baseline. They received once daily oral doses of sotorasib 960mg.

Centrally assessed objective response rate was the trial’s primary endpoint.

Sotorasib showed a confirmed objective response rate (ORR) and disease control rate (DCR) of 37.1% and 80.6%, respectively and a median duration of response of ten months.

Furthermore, it is the first KRAS inhibitor to demonstrate progression-free survival in a Phase II study. These results are in line with Phase I results in previously treated patients with KRAS G12C-mutated advanced NSCLC.

Amgen Research and Development executive vice-president David Reese said: “Targeting KRAS has been a 40-year quest by scientists and researchers around the world, and we are extremely pleased that sotorasib has successfully demonstrated rapid, deep and durable responses in this registrational Phase II study that was conducted in record time.

“We are proud that sotorasib may potentially become the first approved targeted therapy for these patients.”

In addition, more than 80% of patients achieved disease control, and the median tumour shrinkage among all responders was 60%.

Amgen has already made regulatory submissions in the US, the UK, EU, Australia, Brazil and Canada to bring sotorasib to NSCLC patients soon.

Last October, Amgen, Cytokinetics and Servier reported mixed results from the Phase III GALACTIC-HF clinical trial of investigational drug omecamtiv mecarbil in patients with heart failure with reduced ejection fraction (HFrEF).