FDA awards accelerated approval to Imfinzi (durvalumab) in urothelial carcinoma - AstraZeneca/MedImmune

AstraZeneca and MedImmune announced that the FDA has granted accelerated approval to Imfinzi (durvalumab). Imfinzi is indicated for the treatment of patients with locally advanced or metastatic urothelial carcinoma (mUC) who have disease progression during or following platinum-containing chemotherapy, or whose disease has progressed within 12 months of receiving platinum-containing chemotherapy before (neoadjuvant) or after (adjuvant) surgery. Imfinzi is approved under the FDA�s accelerated approval pathway, based on tumour response rate and durability of response. Continued approval for this indication may be contingent upon verification and description of clinical benefit in confirmatory trials.

The accelerated FDA approval is based on data from Study 1108. This Phase I/II trial evaluated the safety and efficacy of Imfinzi in patients with locally-advanced or metastatic urothelial carcinoma of the bladder. Patients had progressed while on or after a platinum-containing chemotherapy, including those who progressed within 12 months of receiving therapy in a neoadjuvant or adjuvant setting.

In the trial, Imfinzi demonstrated rapid and durable responses, with an objective response rate (ORR) of 17.0% in all evaluable patients, regardless of PD-L1 status, and 26.3% in patients with PD-L1 high-expressing tumours (as determined by the VENTANA PD-L1 (SP263) Assay, Ventana Medical Systems Inc., a member of the Roche Group). PD-L1 high was defined as more than 25% of tumour cells (TC) or tumour-infiltrating immune cells (IC) expressing membrane PD-L1 if ICs involved more than 1% of the tumour area, or TC above 25% or IC=100% if ICs involved less than 1% of the tumour area. Additionally, approximately 14.3% of all evaluable patients achieved partial response and 2.7% achieved complete response. Of patients who had received only neoadjuvant or adjuvant therapy prior to trial entry, 24% (n=9) responded. Based on a secondary endpoint in this single-arm trial, median time to response was six weeks. Among the total 31 responding patients, 14 patients (45%) had ongoing responses of six months or longer and five patients (16%) had ongoing responses of 12 months or longer.