Formal discussant, Hossein Borghaei, MS, DO, of Fox Chase Cancer Center, was guardedly optimistic about the IMpower132 trial results. “The study met its primary endpoint, and investigator-assessed progression-free survival was superior in the investigational arm. Overall survival was not mature, but it numerically favors the atezolizumab (Tecentriq)/carboplatin/pemetrexed (Alimta) arm. We need longer follow-up to see if survival will turn out to be positive,” he told listeners.

Hossein Borghaei, MS, DO

Dr. Borghaei noted that even though patients with a high expression of programmed cell death ligand 1 (PD-L1) had a greater benefit from the atezolizumab combination, both PD-L1–high and PD-L1–negative patients did better than control patients. “For PD-L1–negative patients, the progression-free survival curves separate later, but they remain separate, with a 55% reduction in the risk of disease progression,” he continued.

The group treated with 4 cycles of chemotherapy had a slightly better outcome than those who received 6 cycles. Dr. Borghaei said a possible reason for that may be an adverse effect of too much chemotherapy with a checkpoint inhibitor.

“The percentage of patients who received subsequent cancer therapies bothers me,” noted Dr. Borghaei. “More than half of the controls received subsequent therapy, whereas only about one-third of the experimental arm had any subsequent therapy,” he said. This may be a factor to consider when evaluating these study results. ■

DISCLOSURE: Dr. Borghaei has received research support for clinical trials from Millennium, Merck/Celgene, and BMS/Lilly; is an advisor or consultant to BMS, Lilly, Genentech, Celgene, Pfizer, Merck, EMD-Serono, Boehringer Ingelheim, AstraZeneca, Novartis, Genmab, Regeneron, BioNTech, Cantargia AB, Amgen, and AbbVie; and is on the data and safety monitoring board of the University of Pennsylvania, CAR T Program and Takeda.