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Purpose: Pembrolizumab demonstrated antitumor activity and safety in the phase II KEYNOTE-224 trial in previously treated patients with advanced hepatocellular carcinoma (HCC). KEYNOTE-240 evaluated the efficacy and safety of pembrolizumab in this population., Patients and Methods: This randomized, double-blind, phase III study was conducted at 119 medical centers in 27 countries. Eligible patients with advanced HCC, previously treated with sorafenib, were randomly assigned at a two-to-one ratio to receive pembrolizumab plus best supportive care (BSC) or placebo plus BSC. Primary end points were overall survival (OS) and progression-free survival (PFS; one-sided significance thresholds, P = .0174 [final analysis] and P = .002 [first interim analysis], respectively). Safety was assessed in all patients who received ≥ 1 dose of study drug., Results: Between May 31, 2016, and November 23, 2017, 413 patients were randomly assigned. As of January 2, 2019, median follow-up was 13.8 months for pembrolizumab and 10.6 months for placebo. Median OS was 13.9 months (95% CI, 11.6 to 16.0 months) for pembrolizumab versus 10.6 months (95% CI, 8.3 to 13.5 months) for placebo (hazard ratio [HR], 0.781; 95% CI, 0.611 to 0.998; P = .0238). Median PFS for pembrolizumab was 3.0 months (95% CI, 2.8 to 4.1 months) versus 2.8 months (95% CI, 2.5 to 4.1 months) for placebo at the first interim analysis (HR, 0.775; 95% CI, 0.609 to 0.987; P = .0186) and 3.0 months (95% CI, 2.8 to 4.1 months) versus 2.8 months (95% CI, 1.6 to 3.0 months) at final analysis (HR, 0.718; 95% CI, 0.570 to 0.904; P = .0022). Grade 3 or higher adverse events occurred in 147 (52.7%) and 62 patients (46.3%) for pembrolizumab versus placebo; those that were treatment related occurred in 52 (18.6%) and 10 patients (7.5%), respectively. No hepatitis C or B flares were identified., Conclusion: In this study, OS and PFS did not reach statistical significance per specified criteria. The results are consistent with those of KEYNOTE-224, supporting a favorable risk-to-benefit ratio for pembrolizumab in this population.

Purpose: To investigate the relationship of pembrolizumab pharmacokinetics (PK) and overall survival (OS) in patients with advanced melanoma and non-small cell lung cancer (NSCLC)., Patients and Methods: PK dependencies in OS were evaluated across three pembrolizumab studies of either 200 mg or 2 to 10 mg/kg every 3 weeks (Q3W). Kaplan-Meier plots of OS, stratified by dose, exposure, and baseline clearance (CL 0 ), were assessed per indication and study. A Cox proportional hazards model was implemented to explore imbalances of typical prognostic factors in high/low NSCLC CL 0 subgroups., Results: A total of 1,453 subjects were included: 340 with pembrolizumab-treated melanoma, 804 with pembrolizumab-treated NSCLC, and 309 with docetaxel-treated NSCLC. OS was dose independent from 2 to 10 mg/kg for pembrolizumab-treated melanoma [HR = 0.98; 95% confidence interval (CI), 0.94-1.02] and NSCLC (HR = 0.98; 95% CI, 0.95-1.01); however, a strong CL 0 -OS association was identified for both cancer types (unadjusted melanoma HR = 2.56; 95% CI, 1.72-3.80 and NSCLC HR = 2.64; 95% CI, 1.94-3.57). Decreased OS in subjects with higher pembrolizumab CL 0 paralleled disease severity markers associated with end-stage cancer anorexia-cachexia syndrome. Correction for baseline prognostic factors did not fully attenuate the CL 0 -OS association (multivariate-adjusted CL 0 HR = 1.64; 95% CI, 1.06-2.52 for melanoma and HR = 1.88; 95% CI, 1.22-2.89 for NSCLC)., Conclusions: These data support the lack of dose or exposure dependency in pembrolizumab OS for melanoma and NSCLC between 2 and 10 mg/kg. An association of pembrolizumab CL 0 with OS potentially reflects catabolic activity as a marker of disease severity versus a direct PK-related impact of pembrolizumab on efficacy. Similar data from other trials suggest such patterns of exposure-response confounding may be a broader phenomenon generalizable to antineoplastic mAbs. See related commentary by Coss et al., p. 5787 ., (©2018 American Association for Cancer Research.)

The programmed death-1 inhibitor pembrolizumab has demonstrated efficacy and safety in clinical trials for treating advanced (unresectable/metastatic) melanoma. We investigated the real-world utilization of pembrolizumab and associated patient outcomes for advanced melanoma in US community oncology practices. This retrospective, observational study used deidentified data from electronic health records for adult patients with advanced melanoma who received pembrolizumab at The US Oncology Network sites from September 2014 through December 2015, with follow-up through September 2016. Patients enrolled in clinical trials were excluded. Overall survival (OS) and physician-stated progression-free survival (PFS) were analyzed from pembrolizumab initiation using Kaplan-Meier, and associations between pembrolizumab therapy and OS/PFS, using multivariable Cox regression. Of 168 patients studied, 110 (65%) were male; the median age was 66 years (range, 26-over 90). Pembrolizumab was prescribed as first-line, second-line, and third-line/later for 39 (23%), 87 (52%), and 42 (25%) patients, respectively. In total, 41 patients (24%) had brain metastases. At pembrolizumab initiation, 21/129 (16%) had Eastern Cooperative Oncology Group performance status (ECOG PS) >1; 51/116 (44%) had elevated lactate dehydrogenase. Median follow-up was 10.5 months (range, 0-25.1); median OS was 19.4 months (95% confidence interval, 14.0-not reached); median PFS was 4.2 months (95% confidence interval, 2.9-5.3). Brain metastases, ECOG PS>1, elevated lactate dehydrogenase, and third-line/later (vs. first-line) pembrolizumab were significant predictors (P<0.01) of decreased survival. Treatment-related toxicity was a discontinuation reason for 25% (29/117) of patients, and for 10 of these 29 patients (6% of the full-study cohort) treatment-related toxicity was the only reported reason. The real-world effectiveness and safety of pembrolizumab for advanced melanoma are consistent with clinical trial findings.