AstraZeneca has received Japanese regulatory approval for Imfinzi (durvalumab) in combination with etoposide plus platinum chemotherapy (carboplatin or cisplatin) to treat extensive-stage small-cell lung cancer (ES-SCLC).

Lung cancer is broadly split into non-small cell lung cancer (NSCLC) and SCLC. SCLC is an aggressive and fast-growing type of lung cancer that usually reappears and advances rapidly, regardless of an initial response to chemotherapy.

Imfinzi is a human monoclonal antibody that targets and blocks the interaction of PD-L1 with PD-1 and CD80, to prevent the inhibition of immune responses by rackling the tumour’s immune-evading tactics.

The drug has been approved to treat Stage-3 NSCLC after chemoradiation therapy in the curative-intent setting, in the US, Japan, China, across the EU and other countries, and is also approved for patients with advanced bladder cancer in the US and a few other countries.

AstraZeneca oncology business unit executive vice president Dave Fredrickson said: “This approval of Imfinzi provides an important new immunotherapy option in Japan for patients with extensive-stage small-cell lung cancer.

“These patients have an especially poor prognosis, with only two per cent surviving beyond five years. Imfinzi, in combination with chemotherapy, delivers a sustained survival benefit and prolonged treatment response with a convenient dosing regimen given every four weeks during maintenance.”

The Japanese regulatory approval for Imfinzi is supported by Phase 3 CASPIAN trial

The Japanese Ministry of Health, Labour and Welfare has approved the drug regimen based on results from the Phase 3 CASPIAN trial, which showed that Imfinzi plus chemotherapy significantly improved the overall survival (OS) compared to chemotherapy alone.

The clinical trial administered a fixed dose of Imfinzi (1,500mg) every three weeks for four cycles, while a combination of the drug with chemotherapy is administered for every four weeks until disease progression.

In the CASPIAN trial, the drug reduced 27% risk of death compared to chemotherapy alone, with 13.0 months median OS than 10.3 months for chemotherapy alone, in 805 patients with ES-SCLC.

The company said that the efficacy and safety results for Japanese patients in the clinical trial were consistent with the overall trial population in a prespecified analysis.

Furthermore, AstraZeneca has obtained the US FDA Priority Review for Imfinzi, for a new four-week, fixed-dose use to treat non-small cell lung cancer (NSCLC) and bladder cancer.

Phase 3 CASPIAN trial investigator Makoto Nishio said: “Patients with extensive-stage small-cell lung cancer in Japan are in urgent need of new options that can provide long-term tumour control and sustained improvements in overall survival.

“This approval of Imfinzi provides Japanese patients with a new, effective and well-tolerated 1st-line treatment option for this disease, and for the first time physicians have the opportunity to combine immunotherapy with cisplatin for these patients.”