On Monday, May 1st, the FDA approved Imfinzi™ (durvalumab). Imfinzi is manufactured by AstraZeneca, and it is a PD-L1 inhibitor indicated for the treatment of patients with locally advanced or metastatic urothelial carcinoma. The immune-oncology drug is intended for use in patients “who have disease progression during or following platinum-containing chemotherapy or who have disease progression within 12 months of neoadjuvant or adjuvant treatment with platinum-containing chemotherapy.”
In addition to the approval of Imfinzi, the FDA also approved the VENTANA PD-L1 (SP263) Assay. The product is manufactured by Ventana Medical Systems, Inc., and was approved “as a complementary diagnostic for the assessment of the PD-L1 protein in formalin-fixed, paraffin-embedded urothelial carcinoma tissue.”
According to the FDA’s announcement, Imfinzi’s “approval was based on one single-arm trial of 182 patients with locally advanced or metastatic urothelial carcinoma whose disease progressed after prior platinum-containing chemotherapy. Durvalumab, 10 mg/kg intravenously, was administered every 2 weeks. Confirmed objective response rate (ORR) as assessed by blinded independent central review per RECIST 1.1, was 17.0% (95% CI: 11.9, 23.3). At the data cutoff for the ORR analysis, median response duration was not reached (range: 0.9+ to 19.9+ months). ORR was also analyzed by PD-L1 expression status as measured by VENTANA PD-L1 (SP263) Assay. In the 182 patients, the confirmed ORR was 26.3% (95% CI: 17.8, 36.4) in 95 patients with a high PD-L1 score and 4.1% (95% CI: 0.9, 11.5) in 73 patients with a low or negative PD-L1 score.”
The most common adverse reactions experienced by patients while taking Imfinzi include:
- Musculoskeletal pain
- Decreased appetite
- Peripheral edema
- Urinary tract infection
Additionally, 43% of patients experienced Grade 3-4 adverse events, including infection and immune-related adverse events such as pneumonitis, hepatitis, colitis, thyroid disease, adrenal insufficiency, and diabetes.
The application, which was granted accelerated approval, priority review, and Breakthrough Therapy Designation, was approved six weeks prior to the FDA’s goal date. In its announcement, FDA states that “as a condition of the accelerated approval, AstraZeneca is required to complete an ongoing clinical trial to confirm clinical benefit of durvalumab.”
For additional information on Imfinzi’s approval, view FDA’s announcement.