Durvalumab Receives Breakthrough Therapy Status

FDA granted a Breakthrough Therapy designation to AstraZeneca/MedImmune’s monoclonal antibody (mAb) durvalumab, a PD-L1 inhibitor meant to treat patients with PD-L1 positive inoperable or metastatic urothelial bladder cancer whose tumors have either progressed or did not respond to platinum-based chemotherapy. The agency granted this designation based on the results from a Phase I clinical trial.

The status from FDA will help expedite the drug through the regulatory process. Bladder cancer is clearly an area of unmet need, as it is associated with a five-year overall survival rate of less than 15%.

Durvalumab would block the cloaking mechanism of PD-L1 by blocking its interaction and binding with PD-1. The drug is also being investigated in clinical trials as a first-line monotherapy for bladder cancer and in combination with tremelimumab (a CTLA-4 mAb) as a first-line therapy for the condition. Both the monotherapy and the combination therapy have estimated filing dates of 2018 in the United States.

If approved, durvalumab would likely compete with Roche's atezolizumab, which is also in development for the treatment of urothelial carcinoma. EvaluatePharma predicts atezolizumab could receive FDA approval in 2016. Roche's candidate will be submitted for consideration for a Breakthrough Therapy designation for patients whose metastatic bladder cancer expresses PD-L1, according to a Roche press release.

Sources: AstraZeneca, Roche