Still some gaps
In a discussion of the study, Jonathan Yeung, MD, PhD, of Princess Margaret Cancer Center, Toronto, congratulated the investigators on their study, noting that “the logistical hurdles must have been tremendous to obtain these data.”
However, Dr. Yeung pointed out some limitations and gaps in the data that were presented. For example, he found that the ratio of the training set to the validation set was unusual. “The training set is usually larger and usually an 80/20 ratio,” he said. “In their design, the validation set is larger, and I’m quite curious about their rationale.
“The conclusion of the study is that a more diverse microbiome was observed in patients with a tumor response than in those without a response,” he continued, “but they don’t actually show the statistical test used to make this conclusion. There is considerable overlap between the groups, and more compelling data are needed to make that conclusion.”
Another limitation was the marked imbalance in the number of patients whose condition responded to nivolumab in comparison with those whose condition did not (20 vs. 417 patients). This could have affected the statistical power of the study.
But overall, Dr. Yeung congratulated the authors for presenting a very impressive dataset. “The preliminary data are very interesting, and I look forward to the final results,” he said.
The study was funded by Ono Pharmaceutical and Bristol-Myers Squibb, which markets nivolumab. Dr. Sunakawa has received honoraria from Bayer Yakuhin, Bristol-Myers Squibb Japan, Chugai, Kyowa Hakko Kirin, Lilly Japan, Nippon Kayaku, Sanofi, Taiho, Takeda, and Yakult Honsha. He has held a consulting or advisory role for Bristol-Myers Squibb Japan, Daiichi Sankyo, and Takeda and has received research funding from Chugai Pharma, Daiichi Sankyo, Lilly Japan, Sanofi, Taiho Pharmaceutical, and Takeda. The Gastrointestinal Cancers Symposium is sponsored by the American Gastroenterological Association, the American Society for Clinical Oncology, the American Society for Radiation Oncology, and the Society of Surgical Oncology.
A version of this article first appeared on Medscape.com.
