Efficacy and safety of PD-1/PD-L1 inhibitors in patients with Merkel Cell Carcinoma: a systematic review and Meta-analysis

• Published in: BMC cancer 2024-11, Vol.24 (1), p.1357-13, Article 1357
• Main Authors: de Moraes, Francisco Cezar Aquino, Kreuz, Michele, de Lara, Isabella Christina Amaral, Lôbo, Artur de Oliveira Macena, Burbano, Rommel Mario Rodríguez
• Format: Article
• Language: English
• Subjects: Aged; B7-H1 Antigen - antagonists & inhibitors; Cancer; Carcinoma, Merkel Cell - drug therapy; Carcinoma, Merkel Cell - pathology; Care and treatment; Cell death; Cell survival; Chemotherapy; Citation management software; Development and progression; Diagnosis; Disease control; Female; Genetic aspects; Humans; Immune Checkpoint Inhibitors - adverse effects; Immune Checkpoint Inhibitors - therapeutic use; Immunotherapy; Male; Medical prognosis; Merkel cell carcinoma; Meta-analysis; Metastases; Metastasis; Middle Aged; Patient outcomes; Patients; PD-1 protein; PD-1/PD-L1 inhibitors; PD-L1 protein; Programmed Cell Death 1 Receptor - antagonists & inhibitors; Progression-Free Survival; Response rates; Sensitivity analysis; Skin cancer; Skin Neoplasms - drug therapy; Skin Neoplasms - mortality; Skin Neoplasms - pathology; Systematic Review; Toxicity; Treatment Outcome
• ISSN: 1471-2407; 1471-2407
• DOI: 10.1186/s12885-024-13129-1

Merkel cell carcinoma (MCC) is a rare and aggressive neuroendocrine skin cancer characterized by high rates of metastasis. Emerging evidence suggests that PD-L1/PD1 blockade holds promise as a therapeutic option for MCC. However, the efficacy and safety of this approach in treating MCC remain incompletely understood. This systematic review and meta-analysis aims to analyze the efficacy and safety of PD-1/PD-L1 blockade for patients with MCC. PubMed, Cochrane, and Embase were searched for studies evaluating patients with MCC undergoing PD-1/PD-L1 treatment. The estimated outcomes were overall response rate (ORR), disease control rate (DCR), progression-free survival (PFS), overall survival (OS), and treatment-related adverse events (TRAEs). We performed the meta-analysis using RStudio v4.4.2 software. A total of 14 reports of 13 different studies encompassing 615 patients were included. The median age ranged from 64 to 77 years. Median follow-up ranged from 7.9 months to 59.3 months. Pooled OS rates at 24 and 36 months were 65.05% (95% CI 44.04-81.49) and 59.58% (95% CI 39.62-76.81), respectively, while pooled PFS rates at 6, 12, and 36 months were 51.78% (95% CI 37.83-65.45), 46.12% (95% CI 29.44-63.72), and 28.73% (95% CI 16.57-45.02), in the same order. DCR proportion was 61.65% (95% CI 54.85-68.03) and ORR was 53.79% (95% CI 47.80-59.68). The frequency of TRAEs of any grade was 61.72% (95% CI 45.75-75.51) and for TRAEs of grade ≥ 3 was 17.60% (95% CI 12.28 to 24.57). This systematic review and meta-analysis revealed that patients with MCC undergoing treatment with PD-1/PDL-1 showed durable responses with continuous and clinically meaningful survival outcomes.