AstraZeneca and its global biologics research and development arm, MedImmune, announced that the US Food and Drug Administration (FDA) has accepted the first Biologics License Application (BLA) for durvalumab, a PD-L1 human monoclonal antibody (mAb), and granted priority review status with a Prescription Drug User Fee Act (PDUFA) set for the second quarter of 2017.

The BLA submission, for the treatment of patients with locally advanced or metastatic urothelial carcinoma (UC) whose disease has progressed during or after one standard platinum-based regimen, is based on the results of the UC cohort of Study 1108 and follows the FDA’s February 2016 Breakthrough Therapy Designation for durvalumab.

Sean Bohen, executive vice president, global medicines development and chief medical officer at AstraZeneca, said: “The BLA acceptance of durvalumab in urothelial cancer is an important milestone for patients who still face considerable unmet medical need in this area. It also represents an exciting advance for our Immuno-Oncology medicines as we continue to develop chemotherapy-free treatments based on the potential clinical benefits of durvalumab, both as monotherapy and in combination.”

As part of a broad development programme, durvalumab is being tested as monotherapy and in combination with tremelimumab (CTLA-4 mAb) in the phase III DANUBE trial as 1st-line treatment for patients with metastatic UC, regardless of eligibility for cisplatin-based chemotherapy.

The combination of durvalumab and tremelimumab is also being studied in Phase III trials in non-small cell lung cancer (NSCLC), head and neck squamous cell carcinoma (HNSCC) and in Phase II and earlier trials in gastric cancer, pancreatic cancer, hepatocellular carcinoma (HCC) and blood cancers. AstraZeneca currently has more than 30 ongoing durvalumab clinical trials in combination with other IO agents and targeted therapies.

Study 1108 is a phase I/II multicentre, open-label dose-escalation and dose-expansion study investigating the safety and efficacy of durvalumab in adult patients with inoperable or metastatic solid tumours.

Urothelial cancer develops in the cells of the bladder lining (urothelium) and is the most common type of bladder cancer. UC accounts for more than 90% of all cases of bladder cancer worldwide and is an area of significant unmet medical need. Current standard of care for UC patients with inoperable or advanced metastatic disease is systemic platinum-based chemotherapy, introduced nearly 30 years ago.

Durvalumab is an investigational human monoclonal antibody directed against programmed death ligand-1 (PD-L1). PD-L1 expression enables tumours to evade detection from the immune system through binding to PD-1 on cytotoxic T lymphocytes. Durvalumab blocks PD-L1 interaction with both PD-1 and CD80 on T cells, countering the tumour's immune- evading tactics and activating the patient's immune system to attack the cancer. Durvalumab received FDA Breakthrough Therapy Designation in patients with PD-L1 positive inoperable or metastatic UC in 2016 and Fast Track Designation in 2015 for the treatment of patients with PD-L1 positive metastatic head and neck squamous cell carcinoma.