RENO, NV—The clinical outcomes and the incidence of adverse events for programmed death-1 checkpoint inhibitors in cancer patients at a VA clinic were different from the data that have been published, according to a new study.

Researchers from the pharmacy service at the VA Sierra Nevada Healthcare System in Reno sought to evaluate the safety and efficacy of programmed death-1 immune checkpoint inhibitors in a clinical practice setting. Results were published in the Journal of Oncology Pharmacy Practice.1

The study team conducted chart reviews on 21 veterans with advanced or metastatic cancers treated with programmed death-1 checkpoint inhibitors between Jan. 1, 2016, and July 31, 2017. The researchers identified 16 patients who were treated with nivolumab, including 12 with nonsmall cell lung cancer, two with melanoma and two with bladder cancer.

In addition, pembrolizumab was used in five patients, including four with melanoma and one with head and neck cancer. Clinical outcomes were assessed based on overall disease control rates, objective response rates, median progression free survival and median overall survival.

Researches evaluated the safety of PD-1 checkpoint inhibitors based on the incidence and the severity of immune-related adverse events as defined by National Cancer Institute Common Terminology Criteria for Adverse Events v4.0.

Results indicated that, for nivolumab, the overall disease control rate was 63%, including 67% in nonsmall cell lung cancer and 100% in melanoma patients. At the same time, the objective response rate was 31%, with partial response 25% and complete response in 6%.

For pembrolizumab, the overall disease control rate was 100%, with objective response rate 100%, partial response 40% and complete response 60%.

In terms of median progression free survival, that was 4.5 months with nivolumab, with 4.5 months in nonsmall cell lung cancer and six months in melanoma. Nivolumab showed median overall survival of 14 months across all patients and 13 months for nonsmall cell lung cancer.

While median progression free survival and overall survival for pembrolizumab have not yet been reached, six-month progression free survival and overall survival rates were calculated as 80% and 100%, respectively. With nivolumab, 6-month and 12-month overall survival rates were 81% and 69%, respectively.

The study reports that The rate of overall toxicities (grades 2-4) was 90% for programmed death-1 checkpoint inhibitors, including 88% with nivolumab and 100% with pembrolizumab. The overall incidences of Grade 3 or greater immune-related adverse events was 24%, occurring in 25% with nivolumab and 20% with pembrolizumab. The major toxicities were endocrine and gastrointestinal related, occurring 71% and 33%, respectively. Most adverse events were clinically manageable, researchers said.

“This difference should be further investigated with a large real-world patient population,” the authors concluded.

Nguyen V, Huq M. Medication use evaluation of programmed death-1 inhibitors in a veteran population. J Oncol Pharm Pract. 2018 Jan 1:1078155218772654. doi: 10.1177/1078155218772654. [Epub ahead of print] PubMed PMID: 29726785.