AstraZeneca and MedImmune announced the US Food and Drug Administration (FDA) 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 tumor response rate and durability of response. Continued approval for this indication may be contingent upon verification and description of clinical benefit in confirmatory trials.
"We are excited to offer Imfinzi as a breakthrough therapy for patients with locally-advanced or metastatic bladder cancer,” Pascal Soriot, Chief Executive Officer of AstraZeneca, said. “Imfinzi is the cornerstone of our extensive Immuno-Oncology program, in development across many tumor types, as monotherapy and in combination. This first approval for Imfinzi is an important milestone in our return to growth and brings us another step closer to our goal of redefining the way cancer is treated."
Imfinzi is also under investigation in the Phase III DANUBE trial as first-line treatment in urothelial carcinoma as monotherapy and in combination with tremelimumab.
The accelerated FDA approval of Imfinzi, a human monoclonal antibody that blocks PD-L1, 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% (95% confidence interval [CI]: 11.9; 23.3) in all evaluable patients, regardless of PD-L1 status, and 26.3% (95% CI: 17.8; 36.4) in patients with PD-L1 high-expressing tumors (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 ≥25% of tumor cells (TC) or tumor-infiltrating immune cells (IC) expressing membrane PD-L1 if ICs involved >1% of the tumor area, or TC≥25% or IC=100% if ICs involved ≤1% of the tumor 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.