Sept. 26 (UPI) -- The Food and Drug Administration's Accelerated Approval Program is bringing drugs to market faster. While there have been concerns about the safety of the program, a new study suggests that changes in usage guidelines are making it through to doctors, who are changing treatment plans accordingly.
Researchers at the University of Pennsylvania's Abramson Cancer Center say the findings suggest that oncologists are able to quickly incorporate the latest guidelines as the FDA continues to review clinical trial data.
The study, published Wednesday in JAMA, focuses on usage rates for two immunotherapies approved for use in the treatment of patients with advanced bladder cancer, the PD-1 inhibitor pembrolizumab and the PD-L1 inhibitor atezolizumab.
Using health records from more than 280 oncology clinics across the United States, researchers examined treatments for 1,965 patients with advanced bladder cancer. Within six months of the FDA's move to restrict the label of both immunotherapies, usage of those therapies dropped by about 50 percent, according to the study.
First launched in 1992, the Accelerated Approval Program was designed to speed the approval of drugs for serious conditions. While traditional approval requires clinical trials resulting in demonstrable clinical benefit, the AAP relies on a less exacting standard.
In the case of cancer patients, a measurable reduction in tumor size may predict clinical benefit, but does not rise to the more demonstrable standard of overall patient survival.
Even after approval, drugs fast tracked under the AAP must still undergo phase 4 confirmatory trials, and, if proven to be less effective than originally believed, the FDA may still withdraw approval.
"Given the rapid expansion of approvals for immunotherapies, understanding how oncologists react to post-approval safety concerns is crucial, and our study suggests uptake of these changing recommendations can occur very quickly," the study's lead author Ravi B. Parikh, an instructor in Medical Ethics and Health Policy at the University of Pennsylvania, said in a press release.
The FDA approved both therapies in 2017, based on AAP guidelines, but data from ongoing phase III studies has since shown that patients had decreased survival when taking these drugs compared to undergoing platinum-based chemotherapy.
In 2018, these new findings led the FDA to restrict the label indications compared to the original approval.
"We felt it was important to evaluate what the data says about this program, and our findings show oncologists are quick to respond to emerging safety data for drugs approved through this process," said study senior author Ronac Mamtani, an assistant professor of Hematology-Oncology at Penn's Perelman School of Medicine.
While the study's results are promising, researchers say further study is needed in continuing to assess the effects of label changes on clinical practice.