Immune Checkpoint Inhibitors in the Treatment of Ocular Surface Cancers: A Review.

Background: Immune checkpoint inhibitors (ICIs) have transformed cancer therapy by targeting key immune pathways such as PD-1, PD-L1, CTLA-4, and LAG-3 to enhance the immune system's ability to combat malignancies. Their use in treating ocular surface tumors is an emerging area of interest, particularly in conjunctival melanoma (CM) and ocular surface squamous neoplasia (OSSN). Some studies have indicated the potential of ICI's in sebaceous gland carcinoma (SeC), conjunctival lymphoma, and Kaposi sarcoma.

Purpose: This review aims to evaluate the role of ICIs in treating ocular surface tumors, focusing on their mechanisms of action, clinical outcomes, and therapeutic potential.

Methods: A literature review was conducted by searching Pubmed for studies published between January 2014 and October 2024. Studies included were original research, clinical trials, case reports and series, and reviews.

Results: ICIs, including pembrolizumab and nivolumab, have shown promising results in CM, achieving tumor regression and disease stabilization in advanced and metastatic cases. ICIs have also demonstrated efficacy in OSSN, particularly in lesions with high tumor mutational burden, with responses ranging from partial to complete resolution. Although clinical data for SeC and conjunctival lymphoma remain limited to isolated reports, these studies suggest a role for ICIs in managing refractory or advanced disease.

Conclusion: ICIs hold transformative potential in improving outcomes for ocular surface malignancies, particularly in cases where conventional treatments fail or pose significant morbidity. Despite their promise, challenges persist, including variable response rates, immune-related adverse events, and the need for reliable predictive biomarkers. Comprehensive prospective studies are necessary to refine the application of ICIs, optimize treatment strategies, and expand therapeutic options for these challenging cancers.