1618 - Comparative-Effectiveness of Pembrolizumab vs. Nivolumab for Patients with Metastatic Melanoma

Background

Anti-PD-1 antibodies have changed the treatment landscape for patients with metastatic melanoma. Two of these antibodies, pembrolizumab (P) and nivolumab (N), are currently FDA approved in the frontline setting for these patients. The efficacy of these drugs has not been directly compared; thus we aimed to compare the overall survival for patients with metastatic melanoma treated with either front line P or N in routine clinical practice.

Methods

This study included patients with advanced melanoma treated with frontline P or N using the U.S. nationwide Flatiron Health electronic health record (EHR)-derived database. Overall survival (OS) from the start of frontline therapy was estimated for each treatment group using Kaplan-Meier curves with a log-rank test. OS comparative-effectiveness was estimated using a propensity score-matched Cox regression model to reduce bias for pairs of P (n = 371) and N treated subjects (n = 371). Propensity scores were generated using age, gender, ECOG, LDH (elevated or not), BRAF (mutated or not), KIT (mutated or not), NRAS (mutated or not), PD-L1 expression (0% or greater), BMI and primary site.

Results

From a total of 7650 melanoma patients, 888 had advanced disease treated with frontline P (n = 486) or N (n = 402). 58% of N treated patients received flat 240 mg q2 week dosing and 38% of P treated patients received flat 200 mg q3 week dosing. Median OS for patients treated with P was 22.6 months(m) and was 23.9 m for those treated with N (p = 0.91). In the propensity score matched analysis (n = 742), there was no difference in survival between patients treated with P or N (HR 1.10; 95% CI 0.87-1.39).

Conclusions

In our retrospective real world analysis of patients with advanced melanoma, no statistical difference in OS was noted between patients treated with frontline P compared to N. This supports the current practice of choosing either P or N based on patient and provider preference.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

Huntsman Cancer Institute.

Funding

Has not received any funding.

Disclosure

K.F. Grossmann: Advisory / Consultancy: Array BioPharma; Advisory / Consultancy: Bristol-Myers Squibb; Advisory / Consultancy: Genentech; Advisory / Consultancy: Novartis; Advisory / Consultancy: Castle Biosciences. S. Patel: Research grant / Funding (institution): Merck. All other authors have declared no conflicts of interest.