Mirati Therapeutics presents positive clinical data with adagrasib as monotherapy and + cetuximab.

Results showed that adagrasib alone and with cetuximab demonstrated significant clinical activity and broad disease control in these patients. The findings (Abstract # LBA6) will be presented at 9:47 a.m. ET as a late-breaking oral presentation during the Presidential Symposium II session at the European Society for Medical Oncology Congress (ESMO) 2021.

Summary of Clinical Results : As of May 25, 2021, 80% of patients enrolled in the adagrasib monotherapy arm (n=46) received at least two prior lines of systemic anticancer therapies, and had a median follow up of 8.9 months. Of the evaluable patients (n=45), results showed an investigator assessed response rate (RR) of 22%, including one unconfirmed partial response (PR), and a disease control rate (DCR) of 87%; the median duration of response (DOR) was 4.2 months. In all enrolled patients, the median progression free survival (PFS) was 5.6 months (95% Confidence Interval, CI: 4.1,8.3). As of July 9, 2021, 90% patients enrolled in the adagrasib plus cetuximab arm (n=32) received at least two prior lines of systemic anticancer therapies, and had a median follow up of 7 months. Of the evaluable patients (n=28), results showed an investigator assessed RR of 43%, including two unconfirmed PRs and a DCR rate of 100%. After the data cutoff date, of the two unconfirmed PRs, follow up scans showed one patient had a confirmed PR, and the second patient progressed. At the time of the analysis, 63% (20/32) of enrolled patients remained on treatment.

Adagrasib monotherapy and in combination with cetuximab was well-tolerated in this study, with a manageable safety profile. Grade 3/4 treatment related adverse events (TRAEs) were observed in 30% of patients treated with adagrasib alone, and in 16% of patients treated with the combination. Treatment related adverse events led to treatment discontinuation in 6% of patients who received combination therapy and in none (0%) of those who received adagrasib monotherapy. No Grade 5 TRAEs were observed in either treatment arm.