NEW YORK – The US Food and Drug Administration's Oncologic Drugs Advisory Committee on Wednesday voted 10 to 1 in favor of maintaining the accelerated approval for Genentech's checkpoint inhibitor atezolizumab (Tecentriq) as a first-line treatment for certain metastatic bladder cancer patients.
The review is part of the agency's industry-wide evaluation of immunotherapy indications that it granted conditional approval to on an accelerated clip using early data, but which subsequently failed confirmatory trials. If the FDA agrees with the expert committee's advice, then atezolizumab will remain on the market for the time being as a first-line option for metastatic bladder cancer patients with PD-L1 positive tumors who are ineligible for cisplatin-containing chemotherapy and patients regardless of PD-L1 status if they are ineligible for any platinum-containing chemo.
The agency granted accelerated approval in 2017 to atezolizumab as a treatment for previously untreated, locally advanced, or metastatic bladder cancer patients who could not receive cisplatin based on results of the IMvigor210 trial. To covert this conditional approval to full approval, Genentech needed to confirm the benefits of the drug in the IMvigor130 study, in which patients received atezolizumab monotherapy, atezolizumab plus platinum-based chemo, or just chemo.
An early review of IMvigor130 by a data monitoring committee found that patients with low PD-L1 expression in the atezolizumab monotherapy arm had shorter survival than those receiving chemotherapy. At this point, the trial stopped enrolling patients with low PD-L1 status in the atezolizumab monotherapy arm, and the first-line indication for the drug was restricted to advanced bladder cancer patients who are ineligible for cisplatin-containing chemo and who had PD-L1 expression in tumor-infiltrating immune cells covering at least 5 percent of the tumor area — or if patients were ineligible for any platinum-containing chemo, then they could receive first-line atezolizumab regardless of their PD-L1 status.
The final PFS analysis in IMvigor130 showed a median progression-free survival of 8.2 months in the atezolizumab plus chemo arm compared to 6.3 months in the chemo only arm. However, in briefing documents for the ODAC meeting, the FDA said that "in the context of an add-on therapy design, [the agency] did not consider [this outcome] to be clinically meaningful." Additionally, the first and second interim overall survival analysis did not reach statistical significance, though a final analysis is slated for 2022.
On Wednesday, ODAC members decided to keep the accelerated approval in place for this bladder cancer indication until the final overall survival analysis in this study. Earlier the same day, the committee also voted five to three, in favor of keeping the accelerated approval for pembrolizumab (Merck's Keytruda) as a first-line bladder cancer treatment for patients who cannot receive cisplatin or carboplatin, despite the failure of a confirmatory trial.
"Today's positive vote reaffirms that Tecentriq fills a significant unmet need for people with previously untreated metastatic bladder cancer, many of whom cannot tolerate standard-of-care chemotherapy and need additional options," Levi Garraway, chief medical officer and head of Genentech's global product development, said in a statement.
Earlier in the week, ODAC also voted in favor of keeping in place the accelerated approval for atezolizumab in combination with chemo for unresectable or advanced triple-negative breast cancer patients whose tumors express PD-L1. "Having now received positive ODAC recommendations in both bladder cancer and triple-negative breast cancer, we will continue to work with the FDA on next steps for Tecentriq in these indications," Garraway said.