Rociletinib, an epidermal growth factor receptor (EGFR) inhibitor, was active in patients with EGFR-mutated non-small cell lung cancer (NSCLC) associated with the T790M resistance mutation, a study published in The New England Journal of Medicine has shown.
For the phase I/II study, researchers enrolled 130 patients with EGFR-mutated NSCLC who had disease progression during previous treatment with an existing EGFR inhibitor.
Of those, 57 received the free-base form of rociletinib 150mg once daily to 900mg twice daily, while the remaining patients received the hydrogen bromide salt (HBr) form 500 to 1000mg twice daily in continuous 21-day cycles.
Efficacy results showed that the objective response rate among the 46 evaluable patients with T790M-positive disease was 59% (95% CI: 45-73) and was 29% (95% CI: 8-51) among the 17 patients with T790M-negative disease.
The analysis included patients who received the free-base form at a dose of 900mg twice daily or the HBr form at any dose.
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In regard to safety, the study showed that the only common dose-limiting toxicity was hyperglycemia, but researchers did not identify a maximum tolerated dose.
Resistance to EGFR inhibitors is often mediated by the T790M EGFR mutation, but rociletinib has shown activity inEGFR-mutated NSCLC with or without T790M in preclinical models.