Pembrolizumab in the treatment of advanced/metastatic melanoma: a single-center institution experience

Monitoring real-life utilization of pembrolizumab in advanced melanoma using the Portuguese National Cancer Registry

OBJECTIVES

To evaluate the effectiveness and safety of pembrolizumab use in advanced melanoma in a real-life context; and to explore the existence of an efficacy-effectiveness gap, comparing registry data with the reference clinical trial.

METHODS

This study followed the guidelines for good pharmacoepidemology practice. An ambispective cohort was constituted, initiating the observation upon drug approval (17/07/2015) and following exposed patients until death or cut-off date (15/11/2019). The primary outcome was overall survival (OS); secondary outcomes comprised progression-free survival (PFS), overall response rate (ORR) and the occurrence of adverse events (AE). For all survival analyses, the Kaplan-Meier estimator was used, considering a 95% confidence interval (CI), aside with one-year survival rates.

RESULTS

A total of 125 patients constituted the cohort, originating from 16 hospitals in Portugal. Median OS was estimated to be 16.9 months (CI_95% 11.3-25.5) and the probability of survival after 1 year was 57.5% (CI_95% 48.4%-65.6%). Median PFS was estimated to be 4.8 months (CI_95% 3.9-6.7) and the probability of remaining progression-free after 1 year was 32.8% (CI_95% 24.8-41.1). ORR was 30.4% (CI_95% 22.5%-39.3%). AEs were experienced by 82% of patients, and 27% experienced AE≥ grade 3.

CONCLUSIONS

Our data suggest lower effectiveness in a real-life context than the efficacy reported in the clinical trial. Safety data seems, however, quite comparable to KEYNOTE-006.

Real-world treatment practice in patients with advanced melanoma

Introduction

The treatment outcomes of patients with advanced/metastatic melanoma were poor before the use of new therapeutic options.

Material and methods

A retrospective analysis was conducted among 287 patients with unresectable stage III and stage IV melanoma treated at the Maria Sklodowska-Curie National Research Institute of Oncology Cracow Branch, from 2013 to 2019. All enrolled patients were treated with immunotherapy (IT; consisting of pembrolizumab/nivolumab, or ipilimumab) or target therapy (TT; consisting of vemurafenib ±cobimetinib or dabrafenib ±trametinib) in at least one treatment line.

Results

mutation was detected in 152 (55%) patients. In general, the majority of patients (92%) were in very good or good condition (Eastern Cooperative Oncology Group [ECOG] 0 or 1). Brain metastasis was detected in 64 (22%) patients. Median OS and PFS in the experimental group from the beginning of the first-line treatment were 14.9 and 6.7 months, respectively. Across the study population, as a first-line treatment patients received IT, TT as well as CHT, and the median OS was 19.2, 12.6 and 15.9 months, respectively. Multivariate analysis confirmed that normal LDH levels, no brain metastases, ECOG 0, and objective response to the treatment were strong predictors of longer OS. For PFS, absence of brain metastases, ECOG 0, and treatment response were found to be predictive factors on multivariate analysis.

Conclusions

The administration of new therapies for the treatment of patients with advanced/disseminated melanoma significantly prolonged survival in this group of patients. Nevertheless, further studies should be conducted to assess the effectiveness of various sequences of treatment.

Real-world experience with pembrolizumab in patients with advanced melanoma: A large retrospective observational study

Pembrolizumab has been approved in the United States for treating advanced melanoma for >4 years. We examined real-world pembrolizumab use and associated outcomes in US oncology clinical practices, including patients who would not be eligible for clinical trials.Flatiron Health longitudinal database was used to identify adult patients with advanced melanoma initiating ≥1 dose of pembrolizumab from September 4, 2014, through December 31, 2016, with follow-up through December 31, 2017. Patients in any clinical trial during the study period were excluded. Overall survival (OS) and time on treatment from pembrolizumab initiation were analyzed using the Kaplan-Meier (KM) method. Subgroup analyses were conducted to examine OS for several patient characteristics including Eastern Cooperative Oncology Group (ECOG) performance status >1, brain metastases, and corticosteroids before pembrolizumab initiation.Pembrolizumab was administered to 315 (59%), 152 (29%), and 65 (12%) patients as first-, second-, and third-line/later therapy. Median age at pembrolizumab initiation was 68 years (range, 18-84); most patients were male (66%) and white (94%). Of those with available data, 38% had BRAF-mutant melanoma, 21% had elevated lactate dehydrogenase (LDH) level, and 23% had ECOG >1. Overall, 18% had brain metastases, and 23% were prescribed corticosteroids <3 months before initiating pembrolizumab. Median study follow-up was 12.9 months (range, 0.03-39.6). Median OS was 21.8 months (95% confidence interval [CI] 16.8-29.1); KM 1-year and 2-year survival rates were 61% and 48%, respectively; and median time on pembrolizumab treatment was 4.9 months (95% CI 3.7-5.5). Median OS for first-line pembrolizumab was not reached, and for second-line and third-line/later was 13.9 and 12.5 months, respectively (log-rank P = .0095). Significantly better OS (all P ≤.0014, log-rank test) was evident for patients with ECOG performance status (PS) of 0 to 1 (vs >1), normal (vs elevated) LDH level, and no (vs yes) corticosteroid prescription <3 months before. No difference was recorded in OS by brain metastases (log-rank P = .22) or BRAF mutation status (log-rank P = .90).These findings support effectiveness of pembrolizumab in the real-world clinical setting and provide important insights into patient characteristics and outcomes associated with pembrolizumab therapy for a heterogeneous patient population with advanced melanoma, including patients who would not be eligible for clinical trials.