The FDA has expanded its approval of atezolizumab (Tecentriq) for the treatment of advanced bladder cancer to include the initial therapy of patients who are not eligible for cisplatin chemotherapy.
The US Food and Drug Administration (FDA) has expanded its approval of atezolizumab (Tecentriq, Genentech) for the treatment of advanced bladder cancer. The new indications allow for its use as initial therapy in urothelial carcinoma patients who are not eligible for cisplatin chemotherapy.
“Atezolizumab is the first therapy ever to be approved for these typically frail patients, who otherwise do not have good treatment options,” said Arjun V. Balar, MD, of NYU Langone and its Perlmutter Cancer Center in New York and the lead investigator of the study that led to the approval, in a press release. “Indeed, it may be the only therapy some patients need.”
Atezolizumab, a PD-L1 inhibitor, was initially approved to treat advanced bladder cancer in May 2016, in patients who had received platinum-based chemotherapy; the drug has been granted accelerated review by the FDA. The new indication is based on results from the open-label, multicenter, single-arm phase II trial known as IMvigor210; the approval was specifically based on results from Cohort 1 of this trial, which included 119 patients.
All patients in that cohort had locally advanced or metastatic urothelial carcinoma, and all were ineligible for cisplatin-containing chemotherapy; they were either previously untreated or had disease progression at least 12 months following neoadjuvant or adjuvant chemotherapy.
There were 28 confirmed responders to atezolizumab in this group, for an overall response rate (ORR) of 23.5%; 6.7% had a complete response and 16.8% had a partial response. The median duration of response has not yet been reached.
When stratified by PD-L1 expression, those with expression of at least 5% in tumor-infiltrating immune cells (32 patients) had an ORR of 28.1%; those with lower PD-L1 expression had an ORR of 21.8%. The median duration of response also has not been reached in either of these subgroups.
The most common grade 3/4 adverse events (AEs) included fatigue in 8% of patients, urinary tract infection in 5%, anemia in 7%, diarrhea in 5%, and several others at similar or lower rates. There were five people (4.2%) who experienced sepsis, cardiac arrest, myocardial infarction, respiratory failure or respiratory distress that led to death. Atezolizumab was discontinued for AEs in five patients (4.2%).
The phase III IMvigor211 study is now ongoing, comparing atezolizumab to chemotherapy as initial treatment in certain bladder cancer patients. “It is encouraging to see continued progress in the treatment of advanced bladder cancer, which until last year had not seen any major advancements in more than 30 years,” said Andrea Maddox Smith, the CEO of the Bladder Cancer Advocacy Network, in a press release.