Evaluation of Immune Checkpoint Inhibitors' Efficacy for the Treatment of Locally Metastatic Melanoma in a Country with Limited Drug Supply

Abstract

Background: Immune checkpoint inhibitors have demonstrated remarkable efficacy in treating melanoma in various regions. However, in countries with a non-continuous drug supply, ensuring consistent access to pembrolizumab becomes a critical concern. Objective: This study was to evaluate the efficacy of Pembrolizumab in metastatic and locally advanced melanoma in Iraq, where additional treatment-related factors may adversely affect the ultimate therapeutic outcomes. Methodology: This retrospective study was conducted from October 2020 to March 2023 in multiple healthcare centers across Iraq (Oncology Teaching Hospital, The National Teaching Hospital for cancer Treatment in Middle Euphrates, Anbar Cancer Center, and Al-Amal National Hospital. One hundred cases with metastatic melanoma from October 2020 to March 2023 were included in this study. A retrospective analysis of medical records and treatment outcomes of patients received pembrolizumab was conducted. The evaluation considered the challenges associated with interrupted drug supply, including treatment delays, number of cycles, missed doses, and potential impact on treatment outcomes. The main focus of the study was on overall survival. Data was collected from multiple healthcare centers. Kaplan-Meier survival curves and Cox regression were used in the evaluation of Pembrolizumab Efficacy. Results: The 2-year survival probability was 42.0% for the entire cohort. Those with interruption of treatment had significantly lower survival than those without (38% vs. 51.0%, log-rank = 0.082). On the other hand, cases with 10 cycles of Pembrolizumab or more had better survival than those with less than ten (62.0% vs. 27.0%, log-rank <0.001). Conclusion: Factors like smoking history, having a shorter period of follow-up, receiving fewer Pembrolizumab treatment cycles, and experiencing treatment interruption, which could result from the noncontinuous or limited drug supply in low- and middle-income countries, significantly decrease the 2-year survival probability and might put the patient at a higher risk of death from advanced melanoma. Bangladesh Journal of Infectious Diseases, June 2026;13(1):181-187