(Sharecast News) - AstraZeneca announced on Tuesday that the Japanese Ministry of Health, Labour and Welfare has approved Tagrisso (osimertinib) for the first-line treatment of patients with inoperable or recurrent epidermal growth factor receptor mutation-positive non-small cell lung cancer (NSCLC), following priority review.The FTSE 100 drugs giant said the approval was based on results from the global Phase III FLAURA trial, which included Japanese patients and which was published in the New England Journal of Medicine.It said the FLAURA trial compared Tagrisso to current first-line EGFR tyrosine kinase inhibitors, erlotinib or gefitinib, in previously-untreated patients with locally-advanced or metastatic EGFR-mutated NSCLC.In the trial, Tagrisso was said to have demonstrated "superior" progression-free survival of 18.9 months, compared with 10.2 months for the comparator arm, and that benefit was consistent across all subgroups including in patients with or without central nervous system metastases, which AstraZeneca said was an important benefit for lung cancer patients.Safety data for Tagrisso in the FLAURA trial was in line with that observed in prior clinical trials.Tagrisso was reportedly generally well tolerated, with grade 3 or higher adverse events occurring in 34% of patients taking Tagrisso and 45% in the comparator arm.The most common adverse reactions in patients treated with Tagrisso were rash or acne, diarrhoea, dry skin or eczema, and nail disorder including paronychia.Tagrisso has now received approval in 40 countries for the first-line treatment of patients with metastatic EGFRm NSCLC, including the US, Japan and in Europe.Other global health authority reviews and submissions were ongoing."Tagrisso is already approved in Japan for the treatment of patients with EGFR T790M mutation-positive inoperable or recurrent NSCLC that is resistant to existing first-line EGFR-inhibitor medicines," said AstraZeneca's head of the oncology business unit Dave Fredrickson."Today's approval moves the use of Tagrisso to the first-line setting, replacing older medicines which, given the high prevalence of the EGFR mutation in Japan, offers an important new treatment option for these patients."