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

The US regulatory agency has accepted the company’s supplemental Biologics License Application (sBLA) for Imfinzi, which is supported by data from several clinical trials, including results from the Phase 3 CASPIAN trial in patients with ES-SCLC, using the four-week, fixed-dose regimen.

The approval would enable the intravenous administration of Imfinzi at a fixed dose of 1,500mg for every four weeks, to treat unresectable Stage 3 NSCLC after chemoradiation therapy and previously treated advanced bladder cancer, along with the approved dosing in extensive-stage small cell lung cancer (ES-SCLC).

AstraZeneca said that the new dosing is planned to be rolled out as an alternative to the approved weight-based dosing of 10mg/kg every two weeks, once it is approved.

AstraZeneca oncology business unit executive vice president Dave Fredrickson said: “The new less-frequent dosing option for non-small cell lung cancer and bladder cancer will simplify and improve treatment by enabling continuity of care while minimising the risk of exposure to infection in the healthcare setting.

“This takes on particular urgency during the current pandemic, as doctors care for patients at high risk of Covid-19 complications. We are working with health authorities in the US and other countries to bring the option of four-week, fixed dosing for Imfinzi to patients around the world as soon as we can.”

AstraZeneca is testing Imfinzi as a monotherapy and in combination with tremelimumab

Imfinzi is a human monoclonal antibody, designed to target PD-L1 and blocks the interaction of PD-L1 with PD-1 and CD80, to address the tumour’s immune-evading strategies and prevent the inhibition of immune responses.

The company is testing Imfinzi as a monotherapy and in combination with tremelimumab, an anti-CTLA4 monoclonal antibody and as a treatment for patients with NSCLC, SCLC, bladder cancer, head and neck cancer, liver cancer, biliary tract cancer, cervical cancer and other solid tumours.

The drug has been approved in the US, Japan, China, across the EU and in many other countries to treat unresectable, Stage III NSCLC after chemoradiation therapy, and also approved in the US and other countries for previously treated patients with advanced bladder cancer.

Also, the drug is has been approved in the US and is under review in Japan and other countries, to treat ES-SCLC. The regulatory approvals are based on the Phase 3 PACIFIC trial.