Osimertinib improves progression-free survival compared to standard first line therapy in Asian patients with EGFR-mutated non-small-cell lung cancer (NSCLC), according to the Asian subset analysis of the FLAURA trial presented at the ESMO Asia 2017 Congress.
EGFR mutations occur in 30-40% of NSCLC in Asian populations compared to 10-15% in Western populations. The phase III FLAURA trial compared osimertinib, a third generation EGFR-tyrosine kinase inhibitor (TKI), to standard of care EGFR-TKIs (erlotinib or gefitinib) as first line therapy in NSCLC patients with EGFR mutations.
A total of 556 patients from Asia, Europe, and North America were randomised 1:1 to treatment with osimertinib or standard of care. Osimertinib improved progression-free survival by 54%. This subset analysis included the 322 Asian patients in the FLAURA trial, of whom 46 were Chinese, 120 were Japanese, and 156 were from other parts of Asia.
The median progression-free survival was 16.5 months with osimertinib compared to 11.0 months for the standard therapy, with a hazard ratio of 0.54 (95% confidence interval, 0.41-0.72; p<0.0001).
The median duration of response was two-fold higher for patients treated with osimertinib (17.6 months) compared to standard of care (8.7 months). The overall response rate was 80% with osimertinib compared to 75% with standard of care treatment. Median overall survival was not reached. The incidence of grade 3 or higher toxicities was lower for osimertinib (40%) than the standard treatment (48%).
Lead author Professor Byoung Chul Cho, Yonsei Cancer Centre, Seoul, Korea, said: "As in the overall trial population, osimertinib provided a significant progression-free survival benefit in Asian patients with EGFR-mutated NSCLC. Asian patients had similar toxicities with osimertinib as the overall FLAURA population. Osimertinib should be the preferred first line treatment for EGFR-mutant NSCLC in Asia."
Commenting on the findings Professor James CH Yang, chair, graduate institute of oncology, National Taiwan University College of Medicine, Taipei City, Taiwan, said: "The results of this subset analysis are quite compatible with the findings in the overall population presented at the ESMO 2017 Congress in Madrid. We can therefore conclude that osimertinib can be considered as the standard of care for the first line treatment of Asian advanced NSCLC patients with EGFR mutations."
"The proportion of patients having adverse events that caused them to stop taking osimertinib was similar in the overall (13%) and Asian (15%) populations," added Yang. "We tend to think osimertinib is a well tolerated drug so these discontinuation rates were surprisingly high and need further investigation."
Yang continued: "Although there was no statistical difference between the hazard ratios for progression-free survival, it was numerically lower in non-Asians (0.34) compared to Asians (0.54). There is an ongoing debate as to whether Asian and non-Asian patients with EGFR mutations have distinct responses to EGFR-TKIs. This might be due to variations in clinical practice rather than biology. A meta-analysis of all relevant studies could shed light on this issue."
"It will also be important to know whether Asian and non-Asian patients in the FLAURA trial with brain metastases had similar outcomes," said Yang.
Abstract
Background: Osimertinib is an oral, third-generation, irreversible epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) that selectively inhibits both EGFR-TKI–sensitizing and EGFR T790M resistance mutations. We compared osimertinib with standard EGFR-TKIs in patients with previously untreated, EGFR mutation–positive advanced non–small-cell lung cancer (NSCLC).
Methods: In this double-blind, phase 3 trial, we randomly assigned 556 patients with previously untreated, EGFR mutation–positive (exon 19 deletion or L858R) advanced NSCLC in a 1:1 ratio to receive either osimertinib (at a dose of 80 mg once daily) or a standard EGFR-TKI (gefitinib at a dose of 250 mg once daily or erlotinib at a dose of 150 mg once daily). The primary end point was investigator-assessed progression-free survival.
Results: The median progression-free survival was significantly longer with osimertinib than with standard EGFR-TKIs (18.9 months vs. 10.2 months; hazard ratio for disease progression or death, 0.46; 95% confidence interval [CI], 0.37 to 0.57; P<0.001). The objective response rate was similar in the two groups: 80% with osimertinib and 76% with standard EGFR-TKIs (odds ratio, 1.27; 95% CI, 0.85 to 1.90; P=0.24). The median duration of response was 17.2 months (95% CI, 13.8 to 22.0) with osimertinib versus 8.5 months (95% CI, 7.3 to 9.8) with standard EGFR-TKIs. Data on overall survival were immature at the interim analysis (25% maturity). The survival rate at 18 months was 83% (95% CI, 78 to 87) with osimertinib and 71% (95% CI, 65 to 76) with standard EGFR-TKIs (hazard ratio for death, 0.63; 95% CI, 0.45 to 0.88; P=0.007 [nonsignificant in the interim analysis]). Adverse events of grade 3 or higher were less frequent with osimertinib than with standard EGFR-TKIs (34% vs. 45%).
Conclusions: Osimertinib showed efficacy superior to that of standard EGFR-TKIs in the first-line treatment of EGFR mutation–positive advanced NSCLC, with a similar safety profile and lower rates of serious adverse events.
Authors
Jean-Charles Soria, Yuichiro Ohe, Johan Vansteenkiste, Thanyanan Reungwetwattana, Busyamas Chewaskulyong, Ki Hyeong Lee, Arunee Dechaphunkul, Fumio Imamura, Naoyuki Nogami, Takayasu Kurata, Isamu Okamoto, Caicun Zhou, Byoung Chul Cho, Ying Cheng, Eun Kyung Cho, Pei Jye Voon, David Planchard, Wu-Chou Su, Jhanelle E Gray, Siow-Ming Lee, Rachel Hodge, Marcelo Marotti, Yuri Rukazenkov, Suresh S Ramalingam
[link url="https://www.sciencedaily.com/releases/2017/11/171120093645.htm"]European Society for Medical Oncology material[/link]
[link url="http://www.nejm.org/doi/10.1056/NEJMoa1713137"]New England Journal of Medicine abstract[/link]