The Japanese Ministry of Health, Labour and Welfare has approved Tagrisso (osimertinib, AZD9291) 80mg once-daily tablets for the treatment of patients with epidermal growth factor receptor (EGFR) T790M mutation-positive inoperable or recurrent non-small cell lung cancer (NSCLC) that is resistant to EGFR tyrosine kinase inhibitor (TKI) therapy.
Sean Bohen, Executive Vice President, Global Medicines Development and Chief Medical Officer at AstraZeneca, said: “We continue to move at an unprecedented pace with osimertinib, with the full approval in Japan following closely the recent US and EU approvals. As first-in-class lung cancer treatment directed at the T790M mutation, we are delighted that this targeted medicine is now available to patients in Japan to address the existing unmet medical need.”
Dr. Tetsuya Mitsudomi, Division of Thoracic Surgery, Department of Surgery, Kinki University Faculty of Medicine said: “A significant proportion of Japanese patients with lung cancer have the EGFR mutation and about 60% of them are likely to develop the T790M resistance mutation following initial TKI treatment. Osimertinib enables us to respond to this disease progression in a precise and logical way as clearly demonstrated in clinical trials, with potential to make a meaningful difference to the lives of Japanese patients.”
Approximately 30-40% of Asian patients with NSCLC have the EGFR mutation at diagnosis. Nearly two out of three patients with NSCLC whose disease progresses after treatment with an EGFR-TKI develop the T790M mutation, for which treatment options are currently limited. Osimertinib targets both the EGFR mutation involved in cancer development and T790M, a mutation that makes tumours resistant to existing treatment with EGFR-TKIs. Patients with EGFRm NSCLC, who experience disease progression, should be tested for their mutation status through a validated diagnostic test. AstraZeneca has collaborated with Roche to develop the cobas® EGFR Mutation Test v2 as the companion diagnostic for osimertinib.
The Japanese approval is based on data from the two multinational AURA Phase II trials (AURA extension and AURA2), with 22% of patients enrolled from Japan. The studies demonstrated efficacy in patients who had progressed on or after treatment with an EGFR-TKI and whose tumours tested positive for the EGFR T790M mutation. The overall objective response rate (ORR, a measurement of tumour shrinkage) was 61.3% (95% CI: 54.2% to 68.1%) in AURA extension (n=199), and 70.9% (95% CI: 64.0% to 77.1%) in AURA2 (n=199) (1 May 2015 cut-off).
In the two AURA Phase II studies (n=411), the most commonly reported adverse events assessed by the investigator were rash/acne (37.7%), diarrhoea (36.5%), dry skin/eczema, etc. (28.5%), nail disorder including paronychia, etc (23.4%). In Japanese patients (n=80), the incidence of interstitial lung disease (ILD; including pneumonitis etc.), as assessed by the investigator, for all grades was 6.3% (1 May 2015 cut-off). Warnings and precautions include ILD, QT interval prolongation, hepatic impairment and haematological changes.
AstraZeneca has agreed a Risk Management Plan with the Japanese Health Authority.
The full Japanese approval was granted seven months after the New Drug Application submission in August 2015. The Japanese approval for osimertinib was granted under the Priority Review mechanism of the MHLW, in recognition of the submitted data and the life-threatening nature of the disease. The Japanese approval follows US FDA Accelerated Approval in November 2015 and European Commission conditional marketing authorisation in February 2016. Interactions with regulatory authorities in the rest of the world are ongoing.