The FDA granted accelerated approval to atezolizumab for the treatment of locally advanced or metastatic urothelial carcinoma.
Atezolizumab (Tecentriq, Genentech) — the first and only FDA–approved anti–PD-L1 cancer immunotherapy — is intended for patients with urothelial carcinoma who have disease progression during or following platinum-based chemotherapy, or whose disease has worsened within 12 months of receiving platinum-based chemotherapy before or after surgery.
“Tecentriq is a new medicine that can work with the immune system to treat people with a type of bladder cancer that progressed after platinum-based chemotherapy,” Sandra Horning, MD, chief medical officer and head of Global Product Development at Genentech, said in a press release. “We thank the scientists, doctors, patients and their families who made it possible to bring Tecentriq to people with advanced urothelial carcinoma.”
Results of the phase 2 IMvigor 210 study — composed of 310 patients with locally advanced or metastatic urothelial carcinoma — showed atezolizumab conferred at least partial shrinkage of tumors in 14.8% of all patients, which lasted from 2.1 to more than 13.8 months at the time of the response analysis.
Further, 22% (95% CI, 12.3-34.7) of patients with disease progression following neoadjuvant or adjuvant platinum-containing therapy achieved tumor shrinkage.
A subgroup analysis based on PD-L1 expression showed a greater proportion of patients with PD-L1–positive disease ( 5 % expression) achieved tumor response than patients classified as having negative PD-L1 expression (26% vs. 9.5%).
Because these data suggest the level of PD-L1 expression in tumor-infiltrating immune cells may help identify patients more likely to respond to atezolizumab, the FDA also approved the Ventana PD-L1 (SP142, Ventana Medical Systems) assay to detect PD-L1 protein expression levels on patients’ tumor-infiltrating immune cells.
“Tecentriq provides these patients with a new therapy targeting the PD-L1 pathway,” Richard Pazdur, MD, director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research, said in a press release. “Products that block PD-1/PD-L1 interactions are part of an evolving story about the relationship between the body’s immune system and its interaction with cancer cells.”
The most common grade 3 to 4 adverse reactions associated with atezolizumab included urinary tract infection (9%), anemia (8%), fatigue (6%), dehydration, intestinal obstruction, urinary obstruction, hematuria (3%), dyspnea (4%), acute kidney injury, abdominal pain (4%), venous thromboembolism, sepsis and pneumonia.
Three patients experienced sepsis, pneumonitis or intestinal obstruction that led to death, and treatment was discontinued for adverse reactions in 3.2% of patients.
Continued approval for this indication may be contingent upon verification and description of clinical benefit in confirmatory trials, according to a press release.