Updated data from a phase 1 cohort and a pooled analysis of 2 phase 2 trials demonstrated that osimertinib therapy resulted in a high overall response rate with encouraging duration of response and progression-free survival in patients with epidermal growth factor receptor (EGFR)-mutant and T790M-positive advanced non-small cell lung cancer (NSCLC) who had progressed following EGFR tyrosine kinase inhibitor (TKI) therapy.1
Osimertinib is a potent, oral, irreversible EGFR TKI indicated for the treatment of patients with metastatic EGFR T790M mutation-positive NSCLC. Researchers enrolled 63 patients with EGFR mutation-positive and T790M-positive advanced NSCLC who were pre-treated with an EGFR-TKI into the phase 1 expansion cohort and 411 patients into the phase 2 trials.
In the phase 1 study, results showed that overall response rate was 71% (95% CI, 57 – 82) and median duration of response was 9.6 months (95% CI, 7.7 – 15.6). Median progression-free survival was 9.7 months (95% CI, 8.3 – 13.6).
In the pooled analysis of the phase 2 studies, overall response rate was 66% (95% CI, 61 – 71) with a median duration of response of 12.5 months (95% CI, 11.1 – not calculable). The median progression-free survival and 12-month progression-free survival rates were 11.0 months (95% CI, 9.6 – 12.4) and 47.5% (95% CI, 42.4 – 52.5), respectively.
“We found a response rate and progression-free survival that were consistent between the 2 studies and with earlier reports from the AURA studies,” said lead author Professor James Yang, MD, PhD, director of the Department of Oncology and Department of Medical Research, National Taiwan University Hospital in Taipei, Taiwan.
Dr Yang noted that progression-free survival was longer with osimertinib compared with the 4 to 5 months of progression-free survival benefit provided by chemotherapy; however, osimertinib was not compared directly with chemotherapy in this study.
In regard to safety, the most common treatment-related adverse events were rash and diarrhea.
“Adverse events such as interstitial lung disease and QT prolongation were infrequent, with similar rates to our previous analyses,” Dr Yang said.
“This is good news for patients with EGFR mutations who have failed EGFR TKI, for whom osimertinib is now standard of care. Molecular diagnosis for T790M must now be the standard as well,” Dr Yang said.
- Yang J, Ramalingam SS, Jänne PA, et al. Osimertinib (AZD9291) in pre-treated pts with T790M-positive advanced NSCLC: updated phase 1 (P1) and pooled phase 2 (P2) results. Oral presentation at: European Lung Cancer Conference 2016; April 13-16, 2016; Geneva, Switzerland.