On May 1, 2017, the FDA accelerated the approval of Imfinzi (durvalumab; from AstraZeneca) for the treatment of locally advanced or metastatic bladder cancer (or urothelial carcinoma) in patients whose tumor progressed during or after platinum-containing chemotherapy or within 12 months of neoadjuvant or adjuvant (before or after) treatment with platinum-containing chemotherapy.
Imfinzi is the second PD-L1 inhibitor to receive approval for patients with advanced bladder cancer. The drug is administered as an intravenous infusion over 60 minutes every 2 weeks, until the tumor progresses or until the side effects are unacceptable.
At the same time, the FDA also approved the VENTANA PD-L1 (SP263) Assay, as a complementary diagnostic test for the detection of the PD-L1 protein in patients with bladder cancer.
In the clinical trial that led to this approval, overall, 17% of patients who received intravenous infusion with Imfinzi had their tumor shrink. When the response rate was analyzed by PD-L1 levels, 26.3% of patients with high PD-L1 expression had their tumor shrink versus 4.1% of those with low or no PD-L1 expression.
The most common side effects reported with Imfinzi are fatigue, musculoskeletal pain, constipation, decreased appetite, nausea, peripheral edema, and urinary tract infection, including severe adverse events. Immune-related side effects include infection in the lungs, liver, and colon, as well as thyroid disease, adrenal problems, and diabetes.