It was reported on Tuesday that UK-based AstraZeneca has received regulatory approvals for two major cancer drugs, Imfinzi and Lynparza, in Japan.

The company, along with its biologics research and development arm MedImmune, has received approval from the Japanese ministry of health, labour and welfare for Imfinzi (durvalumab) as maintenance therapy after definitive chemoradiation therapy (CRT) in locally-advanced (stage III) and unresectable non-small cell lung cancer (NSCLC). The approval was based on positive progression-free survival data from the Phase III Pacific trial in unresectable stage III NSCLC. In the trial, Imfinzi indicated an improvement in median PFS of 11.2 months compared with placebo. The pacific trial is a randomised, double-blinded, placebo-controlled and multi-centre study of Imfinzi as treatment in patients with Stage III unresectable NSCLC whose disease has not progressed following platinum-based chemoradiation therapy.

Imfinzi is a human monoclonal antibody, which binds to PD-L1 and stops the interaction of PD-L1 with PD-1 and CD80, helping to counter the tumour's immune-evading tactics and release inhibiting immune responses.

Along with Merck, AstraZeneca has secured approval from Japan's pharmaceuticals and medical devices agency (PMDA) for Lynparza (olaparib) tablets for use in patients with unresectable or recurrent BRCA-mutated (BRCAm), human epidermal growth factor receptor 2 (HER2) negative breast cancer who have received prior chemotherapy. The approval was based on data from the randomised, open-label and phase III OlympiAD trial, which assessed against chemotherapy.

In the trial, Lynparza significantly improved progression-free survival (PFS) compared against chemotherapy and reduced the risk of disease progression or death by 42 percent.

Lynparza is the first targeted treatment to potentially exploit DNA damage response pathway deficiencies, such as BRCA mutations, to preferentially eliminate cancer cells.