Durvalumab showed a promising survival boost in stage III non-small cell lung cancer, and the immunotherapy agent was not as toxic as some thought it would be.
Durvalumab (Imfinzi) continued to show promising results in patients with stage III non-small cell lung cancer (NSCLC) who had previously been treated with concurrent chemoradiation, according to findings from the phase 3 PACIFIC trial.
Researchers and clinicians were also happy to see that the regimen was more tolerable than previously expected, too, explained Beth Sandy, CRNP. Sandy, a nurse practitioner at Penn Medicine, recently discussed the advent of durvalumab for these patients at the 38th Annual CFS Virtual, Interactive conference.
Sandy emphasized the importance of finding efficacious treatment regimens for this patient population, which currently has a 5-year survival rate of about 20%.
“This is a curative intent stage,” she said. “About 25% of patients [with NSCLC] are diagnosed at stage III.”
The trial included 2 randomized groups of patients with stage III NSCLC who had not progressed after chemoradiation. The first group was given 10mg/kg of durvalumab every 2 weeks for up to a year, while the other group was given a placebo — something that many people may find surprising.
“But you have to remember that at the time [of the trial], there was no standard of care,” Sandy explained. “Some people were doing full-dose chemo consolidation, but there was really no evidence whatsoever of an advantage with that.”
At the 4-year follow up point, study findings, which were published in the New England Journal of Medicine, showed that the PD-L1 inhibitor produced better outcomes than the placebo.
The median overall survival (OS) rate for the durvalumab arm was 47.5 months, and 29.1 months in the placebo arm. Additionally, at the time of follow-up, 50% of patients were alive on the durvalumab arm, compared to only 36% on the placebo arm.
“We’ll be really excited to see what that 5-year OS is, which is kind of our benchmark that we use in stage III disease to find out if our patients are being cured of their lung cancer,” Sandy said.
Not only was durvalumab boosting survival outcomes, but it also was not as toxic as some presumed it would be. Sandy explained that clinicians were worried about severe pneumonitis as a result of getting and immunotherapy agent directly after receiving radiation.
However, there was no difference in grade 3 pneumonitis between the two arms. Each had 3% of participants experience the toxicity. When it came to all-grade pneumonitis, there was only a slight increase in the durvalumab arm versus the placebo arm, with 33% and 25%, respectively.
“So we weren’t really giving anyone any more harmful pneumonitis by giving them the immunotherapy right after radiation. Maybe a little bit more incidence, but not in severity where patients are having life-threatening pneumonitis,” Sandy said.