In the results of a meta-analysis of solid organ transplant recipients receiving immune checkpoint inhibitors as cancer treatments, the study authors concluded that immunotherapy could be “high-risk, yet promising” for these patients. These findings were presented at the 2025 ASCO Annual Meeting (Summary 2511). Response rates vary depending on the type of immune checkpoint inhibitor received and the type of cancer.
“This work [is] It is one of the most comprehensive studies to date regarding the use of checkpoint inhibitors in transplant recipients,” the senior author states. Muhammad Awidi, MD, Hematology/Oncology Fellow at Roswell Park Comprehensive Cancer Center in Buffalo, New York. “Our research lays the essential foundation for developing safe treatment protocols and expanding access to life-saving immunotherapy for high-risk groups excluded from immunotherapy clinical trials.”
The findings of the study may allow researchers to suggest an approach that will help improve response rates in patients undergoing solid organ transplantation.
Research methods and results
The study authors conducted a meta-analysis to determine how immune checkpoint inhibitor therapy affects the risk of transplant rejection in cancer patients who have undergone robust organ transplants. Researchers conducted a systematic review of PubMed, Embase, and Scopus databases seeking the outcome of rejection and efficacy of solid organ transplant recipients who received immune checkpoint inhibitors (priority reporting items for systematic reviews and meta-analysis) guidelines. They found 198 related studies, including 331 patients with solid organ transplants of the liver, kidney and heart.
Rejection rates were highest in kidney transplants (46.3%) followed by heart (40.0%) and liver (26.9%) transplants. Rejection rates by class of immune checkpoint inhibitors were highest for anti-PD-1 antibodies (40.6%) followed by anti-CTLA-4 antibodies (25%). No rejection was observed with anti-PD-L1 antibodies. Patients who received immune checkpoint inhibitors before implantation had lower rejection rates than patients treated after implantation (25.9% vs. 40.9%).
The objective response rate was highest for anti-PD-L1 antibodies (72.7%), compared to 41.8% for anti-PD-1 antibodies, 28% for anti-PD-1 and anti-CTLA-4 antibodies, and 25% for anti-CTLA-4 antibodies. Depending on the type of cancer, patients with cutaneous squamous cell carcinoma (49.1%) had the highest objective response rate, followed by hepatocellular carcinoma (40.8%) and melanoma (25.3%).
Multivariate analysis showed that anti-CTLA-4 antibodies had lower risk of rejection after anti-transplantation (odds ratio) [OR] = 0.22; p = .04))immune checkpoint inhibitor treatment after third line (OR = 0.24; p = .01), and corticosteroids (OR = 0.46). The risk of rejection before implantation was 60 days or more washout period (OR = 0.1; p <.001).
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