The influence of immune checkpoint inhibitors on treatment results in cancer patients: Real-world evidence from a single institution in a low-middle-income country.

Abstract

e23370 Background: Immune checkpoint inhibitors (ICIs) enhance anti-tumor immunity by modulating specific immune pathways. Despite demonstrated improvements in survival and quality of life, their use in low and middle-income countries (LMICs) remains constrained by high costs and limited insurance coverage. This study aims to evaluate the effectiveness of ICIs across various cancer subtypes in the South Asian population. Methods: A retrospective cross-sectional study was conducted at the Department of Oncology, Aga Khan University Hospital, Karachi (AKUH), Pakistan. The study included patients aged 18–80 years with biopsy-proven malignancies at any stage who received immune checkpoint inhibitors as part of their treatment between January 2019 and December 2023. Statistical analysis is performed using SPSS, employing descriptive statistics (means, standard deviations, frequencies, and percentages) and inferential tests (t-tests, chi-square tests, ANOVA, correlation, and regression) to assess relationships between variables. The Kaplan-Meier curve is used to calculate progression-free survival (PFS) and overall survival (OS). A p-value of < 0.05 is considered statistically significant. Results: A total of 126 patients were included in the analysis. The cohort showed a male predominance (57.9%), with over half of the patients (55.3%) presenting with stage IV disease, and more than 80% having an ECOG performance status of 0-1. The most frequently observed cancer types were genitourinary (29%), lung (25%), and breast (15%). Majority of the patients (95.1%) received ICIs with chemotherapy, predominantly pembrolizumab (78%), followed by durvalumab (13%). In the entire cohort, the median PFS was 40 months, the median OS was 50 months, and the overall mortality was 32.8%. Across the ICI subgroup, the median PFS and OS in the pembrolizumab group were 58 (95% CI: 45.0–111.5) months and 90 (95% CI: 37.4–142.6) months, respectively. Likewise, in the GU, lung, and breast cancer subgroups, the median PFS was 16 months, 15 months, and 25 months (p = 0.17, HR:0.87, 95% CI: 0.6-1.0), while the median OS was 21 months, 48 months, and 28 months (p = 0.1, HR:0.7, 95% CI: 0.5-1.0), respectively. In multivariate analysis, poor ECOG PS (p < 0.001), diabetes mellitus (p = 0.018), hypertension (p = 0.026), grade ≥ 3 gastrointestinal (p = 0.019), and neurotoxicity (HR = 3.94, p = 0.022) were all independently linked to lower survival. Conclusions: The findings indicate that ICIs improve survival among cancer patients in resource-limited settings. Furthermore, the optimal outcomes depend not only on clinical efficacy, but also on regulatory frameworks, insurance coverage, and institutional capacity, which collectively influence access to ICIs. Larger, multicenter studies are needed to refine patient selection and better manage treatment-related toxicity.