AUTHOR=Cosci Ilaria , De Toni Luca , Del Fiore Paolo , Di Nisio Andrea , Carraro Samuela , Radu Claudia Maria , Bertazza Loris , Mocellin Simone , Pigozzo Jacopo , Crivellaro Giovanna , Coppola Marina , Ferlin Alberto 

TITLE=Anti-CTLA-and anti-PD-1 immune checkpoint inhibitor antibodies impair human sperm motility in-vitro

JOURNAL=Frontiers in Pharmacology

VOLUME=Volume 16 - 2025

YEAR=2025

URL=https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2025.1534975

DOI=10.3389/fphar.2025.1534975

ISSN=1663-9812

ABSTRACT=BackgroundImmune checkpoint inhibitors (ICIs), namely, anti-cytotoxic T lymphocyte-associated protein 4 (CTLA-4) monoclonal antibody Ipilimumab and anti- and programmed cell death 1 (PD-1) monoclonal antibodies Nivolumab, and Pembrolizumab, have improved the treatment outcomes for many other cancer types. However, their impact on fertility remains under-explored.MethodsThe possible direct effects of ICIs on human sperm was investigated. Spermatozoa from ten normozoospermic donors were exposed to Ipilimumab, Nivolumab, or Pembrolizumab at concentrations ranging from 1 to 100 ng/mL. Sperm motility was assessed through standard laboratory process. Cell viability and apoptosis markers were evaluated by flow-cytometry using fluorescent Annexin-V probe and Terminal Uridine Nick-End Label (TUNEL) assays. Protein-A-purified therapeutic antibodies (IgG) were also evaluated.ResultsSpermatozoa had high PD-1 (>99%) and negligible CTLA-4 expression. Exposure to ICIs, was associated with a concentration-dependent impairment of sperm motility, noticeable for Pembrolizumab and Ipilimumab since 10 ng/mL, and for Nivolumab since 100 ng/mL. However, no significant effect on cell apoptosis or viability was shown. Purified IgG from ICIs maintained the adverse effect on cell motility without affecting viability.ConclusionICIs, specifically Pembrolizumab, Nivolumab, and Ipilimumab, adversely affect human sperm motility in vitro. Further research is required to understand the underlying mechanisms and clinical implications.