Use of archival versus newly collected tumor samples for assessing PD-L1 expression and overall survival: an updated analysis of KEYNOTE-010 trial

BackgroundIn KEYNOTE-010, pembrolizumab versus docetaxel improved overall survival (OS) in patients with programmed death-1 protein (PD)-L1-positive advanced non-small-cell lung cancer (NSCLC). A prespecified exploratory analysis compared outcomes in patients based on PD-L1 expression in archival versus newly collected tumor samples using recently updated survival data.Patients and methodsPD-L1 was assessed centrally by immunohistochemistry (22C3 antibody) in archival or newly collected tumor samples. Patients received pembrolizumab 2 or 10 mg/kg Q3W or docetaxel 75 mg/m² Q3W for 24 months or until progression/intolerable toxicity/other reason. Response was assessed by RECIST v1.1 every 9 weeks, survival every 2 months. Primary end points were OS and progression-free survival (PFS) in tumor proportion score (TPS) ≥50% and ≥1%; pembrolizumab doses were pooled in this analysis.ResultsAt date cut-off of 24 March 2017, median follow-up was 31 months (range 23–41) representing 18 additional months of follow-up from the primary analysis. Pembrolizumab versus docetaxel continued to improve OS in patients with previously treated, PD-L1-expressing advanced NSCLC; hazard ratio (HR) was 0.66 [95% confidence interval (CI): 0.57, 0.77]. Of 1033 patients analyzed, 455(44%) were enrolled based on archival samples and 578 (56%) on newly collected tumor samples. Approximately 40% of archival samples and 45% of newly collected tumor samples were PD-L1 TPS ≥50%. For TPS ≥50%, the OS HRs were 0.64 (95% CI: 0.45, 0.91) and 0.40 (95% CI: 0.28, 0.56) for archival and newly collected samples, respectively. In patients with TPS ≥1%, OS HRs were 0.74 (95% CI: 0.59, 0.93) and 0.59 (95% CI: 0.48, 0.73) for archival and newly collected samples, respectively. In TPS ≥50%, PFS HRs were similar across archival [0.63 (95% CI: 0.45, 0.89)] and newly collected samples [0.53 (95% CI: 0.38, 0.72)]. In patients with TPS ≥1%, PFS HRs were similar across archival [0.82 (95% CI: 0.66, 1.02)] and newly collected samples [0.83 (95% CI: 0.68, 1.02)].ConclusionPembrolizumab continued to improve OS over docetaxel in intention to treat population and in subsets of patients with newly collected and archival samples.Trial registrationClinicalTrials.gov: NCT01905657.     

Five Year Survival Update From KEYNOTE-010: Pembrolizumab Versus Docetaxel for Previously Treated,Programmed Death-Ligand 1–Positive Advanced NSCLC

IntroductionIn the KEYNOTE-010 study, pembrolizumab improved overall survival (OS) versus docetaxel in patients with previously treated, advanced NSCLC with programmed death-ligand 1 (PD-L1) tumor proportion score (TPS) ≥50% and ≥1%. We report 5-year efficacy and safety follow-up for the KEYNOTE-010 study.MethodsPatients were randomized to pembrolizumab 2 mg/kg or 10 mg/kg once every 3 weeks or docetaxel 75 mg/m² once every 3 weeks for up to 35 cycles (2 y). Patients who completed pembrolizumab treatment and subsequently had recurrence could receive second-course pembrolizumab for up to 17 cycles (1 y). Pembrolizumab doses were pooled in this analysis.ResultsA total of 1034 patients were randomized (pembrolizumab, n = 691; docetaxel, n = 343). Median study follow-up was 67.4 months (range: 60.0‒77.9). The hazard ratio (95% confidence interval) for OS was 0.55 (0.44‒0.69) for patients with PD-L1 TPS ≥50% and 0.70 (0.61‒0.80) with PD-L1 TPS ≥1%. The 5-year OS rates for pembrolizumab versus docetaxel were 25.0% versus 8.2% in patients with PD-L1 TPS ≥50% and 15.6% versus 6.5% with PD-L1 TPS ≥1%. Among 79 patients who completed 35 cycles/2 years of pembrolizumab, the OS rate 3 years after completion (∼5 y from randomization) was 83.0%. A total of 21 patients received second-course pembrolizumab; 11 (52.4%) had an objective response after starting the second course and 15 (71.4%) were alive at data cutoff. Exploratory biomarker analysis revealed that higher tissue tumor mutational burden (≥175 mutations per exome) was associated with improved outcomes with pembrolizumab.ConclusionsPembrolizumab continued to provide long-term benefit than docetaxel in patients with previously treated advanced NSCLC with PD-L1 TPS ≥50% and ≥1%. Our findings confirm pembrolizumab as a standard-of-care treatment in the second-line or later setting.     

A Randomized Phase III Study of Pembrolizumab Versus Pembrolizumab-Carboplatin-Pemetrexed for Locally Advanced or Metastatic Nonsquamous Non-small-cell Lung Cancer with PD-L1 50% or more (LAPLACE-50): Study Protocol

BackgroundPembrolizumab monotherapy or immune checkpoint inhibitor with platinum and pemetrexed combination chemotherapy are the standard therapies for patients with nonsquamous non–small-cell lung cancer (NSCLC) with programmed cell death ligand-1 (PD-L1) tumor proportion score (TPS) ≥ 50%. However, there are no data on the comparative effectiveness of the 2 regimens in patients with nonsquamous NSCLC with PD-L1 TPS ≥ 50%.Patients and MethodsThis randomized, multicenter, phase III trial (LAPLACE-50, jRCTs031200078) was designed to compare the efficacy and safety of pembrolizumab with pembrolizumab-carboplatin-pemetrexed combination in patients with nonsquamous NSCLC with PD-L1 TPS ≥ 50%. Patients are eligible for enrollment if they are at least 20 years old; have pathologically confirmed locally advanced/metastatic nonsquamous NSCLC without sensitizing epidermal growth factor receptor or anaplastic lymphoma kinase mutations; have not received previous systemic therapy for metastatic disease; have an Eastern Cooperative Oncology Group performance status of 0 or 1; and have at least 1 measurable lesion. Patients will be excluded if they have symptomatic central nervous system metastases, interstitial pneumonitis, active autoimmune disease, or are on systemic immunosuppressive treatment. The patients will be randomized 1:1 to pembrolizumab (200 mg) or pembrolizumab (200 mg) plus carboplatin (area under the curve 5) plus pemetrexed (500 mg/m²) on day 1 of each 21-day treatment cycle. The primary endpoint is progression-free survival. The recruitment phase began in August 2020 and will enroll 290 patients.ConclusionIf the primary endpoint is achieved, pembrolizumab could be the first choice for first-line treatment in patients with nonsquamous NSCLC with PD-L1 TPS ≥ 50%.     

KEYNOTE-033: Randomized phase 3 study of pembrolizumab vs docetaxel in previously treated,PD-L1-positive,advanced NSCLC

KEYNOTE-033 (NCT02864394) was a multicountry, open-label, phase 3 study that compared pembrolizumab vs docetaxel in previously treated, programmed death-ligand 1 (PD-L1)-positive, advanced non-small cell lung cancer (NSCLC), with most patients enrolled in mainland China. Eligible patients were randomized (1:1) to pembrolizumab 2 mg/kg or docetaxel 75 mg/m² every 3 weeks. Primary endpoints were overall survival (OS) and progression-free survival and were evaluated sequentially using stratified log-rank tests, first in patients with PD-L1 tumor proportion score (TPS) ≥50% and then in patients with PD-L1 TPS ≥1% (significance threshold: P < .025, one-sided). A total of 425 patients were randomized to pembrolizumab (N = 213) or docetaxel (N = 212) between 8 September 2016 and 17 October 2018. In patients with a PD-L1 TPS ≥50% (n = 227), median OS was 12.3 months with pembrolizumab and 10.9 months with docetaxel; the hazard ratio (HR) was 0.83 (95% confidence interval [CI]: 0.61-1.14; P = .1276). Because the significance threshold was not met, sequential testing of OS and PFS was ceased. In patients with a PD-L1 TPS ≥1%, the HR for OS for pembrolizumab vs docetaxel was 0.75 (95% CI: 0.60-0.95). In patients from mainland China (n = 311) with a PD-L1 TPS ≥1%, HR for OS was 0.68 (95% CI: 0.51-0.89). Incidence of grade 3 to 5 treatment-related AEs was 11.3% with pembrolizumab vs 47.5% with docetaxel. In summary, pembrolizumab improved OS vs docetaxel in previously treated, PD-L1-positive NSCLC without unexpected safety signals; although the statistical significance threshold was not reached, the numerical improvement is consistent with that previously observed for pembrolizumab in previously treated, advanced NSCLC.     

Programmed Death-Ligand 1 Tumor Proportion Score and Overall Survival From First-Line Pembrolizumab in Patients With Nonsquamous Versus Squamous NSCLC

IntroductionFor patients with NSCLC receiving immune checkpoint inhibitors, programmed death-ligand 1 (PD-L1) tumor proportion score (TPS) has been validated as a predictive biomarker for improved overall survival (OS). Nevertheless, its histology-specific predictive value in patients with advanced squamous versus nonsquamous cancers remains unclear. To evaluate the differential value of PD-L1 TPS as a predictive biomarker for OS after first-line pembrolizumab in patients with squamous versus nonsquamous NSCLC.MethodsRetrospective, observational study of patients diagnosed with having advanced NSCLC who were treated between October 2015 and April 2019 at community oncology clinics and academic medical centers in a deidentified electronic health record–derived database. Included patients were diagnosed with having advanced or metastatic NSCLC, received treatment with first-line, single-agent pembrolizumab, and had documentation of PD-L1 testing with a numeric result. Exclusion criteria included alterations in EGFR, ALK, and ROS1. The primary end point was OS from start of first-line pembrolizumab therapy by squamous or nonsquamous histology and PD-1 expression level measured by TPS (low, <50% or high, ≥50%).ResultsThe cohort of 1460 patients with NSCLC who received pembrolizumab as a first-line therapy had a mean age of 72 years. Histology was 28% squamous and 72% nonsquamous. PD-L1 expression was low in 13% and high in 87%. No meaningful differences in age, sex, or smoking history were observed by PD-L1 TPS or histology type. A generalized gamma model adjusting for sex and stage at diagnosis found that for patients with nonsquamous histology, high PD-L1 TPS was significantly associated with improved OS by a median OS difference of 8.4 months (p < 0.001). In contrast, for patients with squamous histology, there was no evidence of association between PD-L1 expression level and OS (p = 0.283). PD-L1–related incremental differences in median OS between the patients with squamous and nonsquamous tumors were significantly different (p = 0.034).ConclusionsAmong patients with NSCLC treated with first-line pembrolizumab, high PD-L1 TPS is associated with OS among patients with nonsquamous NSCLC, but not among patients with squamous NSCLC.     

First-line Pembrolizumab Versus Pembrolizumab Plus Chemotherapy Versus Chemotherapy Alone in Non–small-cell Lung Cancer: A Systematic Review and Network Meta-analysis

BackgroundThis study aimed to comprehensively review the available evidence regarding the efficacy of first-line pembrolizumab for advanced/metastatic non–small-cell lung cancer (NSCLC), and to compare pembrolizumab monotherapy versus pembrolizumab plus chemotherapy versus chemotherapy alone.Materials and MethodsA search of the PubMed, EMBASE, and Cochrane Library databases was performed in July 2018, and abstracts from the American Society of Clinical Oncology meetings (2015-2018) were reviewed. Summaries of the results were pooled using a random-effect model to determine the pooled hazard ratio (HR) for progression-free survival (PFS), overall survival (OS), and their 95% confidence intervals (CIs). A network meta-analysis was used to indirectly compare pembrolizumab monotherapy with pembrolizumab plus chemotherapy.ResultsA total of 4 relevant phase III trials comprising 2754 patients were identified. Pembrolizumab (with or without chemotherapy) led to significant improvements in OS and PFS, irrespective of the programmed cell death ligand 1 (PD-L1) tumor proportion score (TPS). In particular, for the subgroup with PD-L1 TPS ≥ 50%, the HR of PFS was 0.49 (95% CI, 0.32-0.76; P = .001), and that of OS was 0.57 (95% CI, 0.45-0.73; P < .001). In terms of PFS, pembrolizumab plus chemotherapy was superior to pembrolizumab monotherapy with an HR of PFS 0.52 (95% CI, 0.27-0.99; P = .048) for the subgroup with PD-L1 TPS ≥ 50%.ConclusionsFor patients with NSCLC with PD-L1 TPS ≥ 50%, pembrolizumab plus chemotherapy has a better PFS than pembrolizumab monotherapy in this meta-analysis. To confirm this finding, a prospective phase III trial that directly compares the treatments is warranted.     

Systematic evaluation of pembrolizumab dosing in patients with advanced non-small-cell lung cancer

BackgroundIn the phase I KEYNOTE-001 study, pembrolizumab demonstrated durable antitumor activity in patients with advanced non-small-cell lung cancer (NSCLC). We sought to characterize the relationship between pembrolizumab dose, exposure, and response to define an effective dose for these patients.Patients and methodsPatients received pembrolizumab 2 mg/kg every 3 weeks (Q3W) (n = 55), 10 mg/kg Q3W (n = 238), or 10 mg/kg Q2W (n = 156). Response (RECIST v1.1) was assessed every 9 weeks. The relationship between the estimated pembrolizumab area under the concentration–time curve at steady state over 6 weeks (AUC_ss–6weeks) and the longitudinal change in tumor size (sum of longest diameters) was analyzed by regression and non-linear mixed effects modeling. This model was simultaneously fit to all tumor size data, then used to simulate response rates, normalizing the trial data across dose for prognostic covariates (tumor PD-L1 expression and EGFR mutation status). The exposure–safety relationship was assessed by logistic regression of pembrolizumab AUC_ss–6weeks versus occurrence of adverse events (AEs) of interest based on their immune etiology.ResultsOverall response rates were 15% [95% confidence interval (CI) 7%–28%] at 2 mg/kg Q3W, 25% (18%–33%) at 10 mg/kg Q3W, and 21% (95% CI 14%–30%) at 10 mg/kg Q2W. Regression analyses of percentage change from baseline in tumor size versus AUC_ss–6weeks indicated a flat relationship (regression slope P > 0.05). Simulations showed the exposure–response relationship to be similarly flat, thus indicating that the lowest evaluated dose of 2 mg/kg Q3W to likely be at or near the efficacy plateau. Exposure–safety analysis showed the AE incidence to be similar among the clinically tested doses.ConclusionsNo significant exposure dependency on efficacy or safety was identified for pembrolizumab across doses of 2–10 mg/kg. These results support the use of a 2 mg/kg Q3W dosage in patients with previously treated, advanced NSCLC.ClinicalTrials.gov registryNCT01295827.     

A Phase II Study of Pembrolizumab in EGFR-Mutant,PD-L1+, Tyrosine Kinase Inhibitor Naïve Patients With Advanced NSCLC

Background

Despite the significant antitumor activity of pembrolizumab in NSCLC, clinical benefit has been less frequently observed in patients whose tumors harbor EGFR mutations compared to EGFR wild-type patients. Our single-center experience on the KEYNOTE-001 trial suggested that pembrolizumab-treated EGFR-mutant patients, who were tyrosine kinase inhibitor (TKI) naïve, had superior clinical outcomes to those previously treated with a TKI. As TKI naïve EGFR-mutants have generally been excluded from pembrolizumab studies, data to guide treatment decisions in this patient population is lacking, particularly in patients with programmed death ligand 1 (PD-L1) expression ≥50%.

Safety and Efficacy of Dostarlimab in Patients With Recurrent/Advanced Non–small Cell Lung Cancer: Results from Cohort E of the Phase I GARNET Trial

BackgroundDostarlimab is an anti-programmed cell death protein-1 antibody being evaluated in recurrent/advanced solid tumors, including non–small cell lung cancer (NSCLC), in the ongoing Phase I, multi-center, open-label, 2-part (dose escalation and cohort expansion) GARNET study (NCT02715284).Materials and MethodsHere, we report an interim analysis of patients with recurrent/advanced NSCLC who progressed following platinum-based chemotherapy. Patients received dostarlimab (500 mg IV every 3 weeks [Q3W] for Cycles 1-4, then 1000 mg Q6W) until disease progression or unacceptable toxicity for > 2 years. The primary endpoints were immune-related objective response rate (irORR) per investigator-assessed irRECIST and safety.ResultsAs of 8, July 2019, 67 patients with recurrent/advanced NSCLC were enrolled and treated with dostarlimab; the majority had programmed death ligand 1 (PD-L1) tumor proportion score (TPS) < 1% (35.8% of patients) or PD-L1 TPS 1%-49% (29.9% of patients); 7.5% had PD-L1 TPS ≥ 50%, and 26.9% had unknown PD-L1 TPS status. Median follow-up was 13.8 months (range: 0.0-22.6). irORR was 26.9%, including 2 complete and 16 partial responses. The median duration of response of 11.6 months (range: 2.8-19.4). Responses were observed in 2 of 24 (16.7%) patients with PD-L1 TPS < 1%, 4 of 20 (20.0%) patients with PD-L1 TPS 1%-49% and 2 of 5 (40.0%) patients with PD-L1 TPS ≥ 50%. Fatigue (4.5%) was the most common Grade ≥ 3 treatment-related treatment-emergent adverse event (TRAE). Immune-related TRAEs (any grade) were observed in 28.4% of patients.ConclusionDostarlimab demonstrated promising antitumor activity in advanced/recurrent NSCLC that progressed following platinum-based chemotherapy, including across all PD-L1 subgroups, and has an acceptable safety profile.     

KEYNOTE‐025: Phase 1b study of pembrolizumab in Japanese patients with previously treated programmed death ligand 1–positive advanced non–small‐cell lung cancer

Pembrolizumab, a humanized monoclonal antibody against programmed death 1 (PD‐1), has been shown to improve overall survival (OS) in patients with previously treated advanced non–small‐cell lung cancer (NSCLC) with programmed death ligand 1 (PD‐L1) tumor proportion score (TPS) ≥1%. We report safety and efficacy results from the phase 1b KEYNOTE‐025 study, which evaluated pembrolizumab in Japanese patients with previously treated NSCLC. Eligible patients had histologically/cytologically confirmed advanced NSCLC with PD‐L1 TPS ≥1% and had received ≥1 platinum‐doublet chemotherapy. Patients received pembrolizumab 10 mg/kg once every 3 weeks for 2 years or until disease progression/unacceptable toxicity. Primary objectives were to evaluate the safety of pembrolizumab in patients with PD‐L1 TPS ≥1% and the objective response rate (ORR) per RECIST version 1.1 in patients with PD‐L1 TPS ≥50%. Thirty‐eight patients were enrolled and received ≥1 pembrolizumab dose. The median (range) age was 66.0 (41‐78) years, and 61% had received ≥2 prior systemic therapies. Eleven patients (29%) experienced grade 3‐5 treatment‐related adverse events (AE); 9 patients (24%) experienced immune‐mediated AE and infusion reactions, with pneumonitis (11%; any grade) being most common. Among evaluable patients with PD‐L1 TPS ≥50% (n = 11), ORR was 27% (95% CI, 6‐61). Among evaluable patients with PD‐L1 TPS ≥1% (n = 37), ORR was 22% (95% CI, 10‐38). Median (95% CI) progression‐free survival and OS were 3.9 (2.0‐6.2) months and 19.2 (8.0‐26.7) months, respectively. In summary, pembrolizumab was generally well tolerated and showed promising antitumor activity in Japanese patients with previously treated PD‐L1–expressing NSCLC. Outcomes were consistent with those from the phase 3 KEYNOTE‐010 study. (Trial registration number: ClinicalTrials.gov, NCT02007070.)     

Differential Efficacy of Pembrolizumab According to Metastatic Sites in Patients With PD-L1 Strongly Positive (TPS ≥ 50%) NSCLC

BackgroundPembrolizumab has shown significantly better efficacy than platinum doublet chemotherapy in patients with programmed cell death ligand 1 (PD-L1) strongly positive (tumor proportion score ≥ 50%) non–small-cell lung cancer (NSCLC). However, the predictors of response to pembrolizumab have not yet been fully elucidated for patients with PD-L1 strongly positive NSCLC.Patients and MethodsWe retrospectively analyzed 145 patients who had been treated with pembrolizumab for PD-L1 strongly positive (TPS ≥ 50%) NSCLC without an EGFR (epidermal growth factor receptor) mutation or ALK rearrangement from February 2017 to March 2020. Various clinical characteristics, including Eastern Cooperative Oncology Group performance status, treatment line, PD-L1 expression, C-reactive protein level, neutrophil/lymphocyte ratio, and metastatic sites, and the clinical outcome of pembrolizumab treatment were examined.ResultsPatients with higher PD-L1 expression (≥ 75%; n = 90) had a higher objective response rate (ORR) and longer progression-free survival (PFS) compared with those with lower expression (50%-74%; n = 55; ORR, 51% vs. 33%; P = .0305; median PFS, 13.9 months vs. 5.2 months; P = .0111). In addition, 15 patients with liver metastasis (LM) had a significantly lower ORR and shorter PFS than the 130 patients without LM (ORR, 20% vs. 47%; P = .0468; median PFS, 3.4 months vs. 9.4 months; P = .0018). A multivariate analysis indicated that PD-L1 expression and LM were significant predictors of PFS after pembrolizumab treatment (higher PD-L1 expression: hazard ratio, 0.58; 95% confidence interval, 0.38-0.91; P = .0183; presence of LM: hazard ratio, 2.05; 95% confidence interval, 1.03-3.82; P = .0420).ConclusionPD-L1 expression and LM status were predictors of the efficacy of pembrolizumab in patients with PD-L1 strongly positive NSCLC.     

Cost-effectiveness of Pembrolizumab versus Carboplatin-based Chemotherapy as First-line Treatment of PD-L1–positive Locally Advanced or Metastatic Urothelial Carcinoma Ineligible for Cisplatin-based Therapy in the United States

IntroductionPembrolizumab has been approved in the United States (US) for the first-line treatment of patients with advanced or metastatic urothelial carcinoma, who are ineligible for cisplatin-containing chemotherapy and with tumors expressing programmed death-ligand 1 (PD-L1) (Combined Positive Score ≥ 10), or ineligible for any platinum-containing chemotherapy regardless of PD-L1 status. Long-term KEYNOTE-052 data continue to demonstrate pembrolizumab’s meaningful, durable, and well-tolerated antitumor activity. This study evaluates the cost-effectiveness of pembrolizumab versus carboplatin plus gemcitabine as first-line treatment for cisplatin-ineligible patients who have PD-L1–positive tumors from a US third-party healthcare payer’s perspective.Patients and MethodsA partitioned survival model containing 3 health states (progression-free, progressed, and death) was developed. A simulated treatment comparison and a network meta-analysis were conducted to estimate the comparative efficacy of pembrolizumab versus carboplatin-based chemotherapy. Overall survival, progression-free survival, time on treatment, adverse events, and utilities were modeled using the final analyses of the KEYNOTE-052 trial and 4 studies for carboplatin plus gemcitabine. Cost data were estimated using US standard sources and real-world data. Deterministic, probabilistic, and scenario analyses were conducted to assess the robustness of the results.ResultsOver 20 years, pembrolizumab resulted in a mean gain of 2.58 life-years, 2.01 quality-adjusted life-years, and additional costs of $158,561, leading to an incremental cost-effectiveness ratio of $78,925/quality-adjusted life-year compared with carboplatin plus gemcitabine.ConclusionThis study suggests that pembrolizumab is cost-effective compared with carboplatin plus gemcitabine as a first-line therapy for patients with advanced or metastatic urothelial carcinoma who are PD-L1–positive.     

Pembrolizumab plus pemetrexed-platinum for metastatic nonsquamous non–small-cell lung cancer: KEYNOTE-189 Japan Study

Pembrolizumab plus pemetrexed-platinum significantly improved overall survival (OS) and progression-free survival (PFS) with manageable safety compared with placebo plus pemetrexed-platinum in patients with previously untreated metastatic nonsquamous non–small-cell lung cancer (NSCLC) without EGFR/ALK alterations in the global, randomized, double-blind, phase 3 KEYNOTE-189 study. We present results of Japanese patients enrolled in the KEYNOTE-189 global and Japan extension studies. Patients were randomized 2:1 to intravenous pembrolizumab 200 mg or placebo every 3 weeks (Q3W) for up to 35 cycles. All patients received pemetrexed 500 mg/m² plus the investigator’s choice of cisplatin or carboplatin Q3W for four cycles, followed by maintenance pemetrexed 500 mg/m² Q3W (all intravenous). Co–primary endpoints were OS and PFS. Forty Japanese patients enrolled (pembrolizumab, n = 25; placebo, n = 15). At data cutoff (20 May 2019; median time from randomization to data cutoff, 18.5 [range, 14.7‒38.2] months), the median OS was not reached in the pembrolizumab plus pemetrexed-platinum arm; the median OS was 25.9 (95% confidence interval [CI], 11.9‒29.0) months in the placebo plus pemetrexed-platinum arm (hazard ratio [HR] .29; 95% CI, .07‒1.15). The median (95% CI) PFS was 16.5 (8.8‒21.1) compared with 7.1 (4.7‒21.4) months (HR, .62; 95% CI, .27‒1.42), respectively. There were no grade 5 adverse events (AE). Grade 3/4 AE occurred in 72% vs 60% of patients in the pembrolizumab vs placebo arms; 40% vs 20% had immune-mediated AE, and 4% vs 0% had infusion reactions. Efficacy and safety outcomes were similar to those from the global study and support first-line therapy with pembrolizumab plus pemetrexed-platinum in Japanese patients with nonsquamous NSCLC without EGFR/ALK alterations.     

Outcomes to first-line pembrolizumab in patients with non-small-cell lung cancer and very high PD-L1 expression

BackgroundIn non-small-cell lung cancers with programmed death-ligand 1 (PD-L1) expression on ≥50% of tumor cells, first-line treatment with the PD-1 inhibitor pembrolizumab improves survival compared with platinum-doublet chemotherapy. Whether higher PD-L1 levels within the expression range of 50%–100% predict for even greater benefit to pembrolizumab is currently unknown.Patients and methodsIn this multicenter retrospective analysis, we analyzed the impact of PD-L1 expression levels on the overall response rate (ORR), median progression-free survival (mPFS), and median overall survival (mOS) in patients who received commercial pembrolizumab as first-line treatment of non-small-cell lung cancer (NSCLC) with a PD-L1 expression of ≥50% and negative for genomic alterations in the EGFR and ALK genes.ResultsAmong 187 patients included in this analysis, the ORR was 44.4% [95% confidence interval (CI) 37.1% to 51.8%], the mPFS was 6.5 months (95% CI 4.5–8.5), and the mOS was not reached. The median PD-L1 expression level among patients who experienced a response to pembrolizumab was significantly higher than among patients with stable or progressive disease (90% versus 75%, P < 0.001). Compared with patients with PD-L1 expression of 50%–89% (N = 107), patients with an expression level of 90%–100% (N = 80) had a significantly higher ORR (60.0% versus 32.7%, P < 0.001), a significantly longer mPFS [14.5 versus 4.1 months, hazard ratio (HR) 0.50 (95% CI 0.33–0.74), P < 0.01], and a significantly longer mOS [not reached versus 15.9 months, HR 0.39 (95% CI 0.21–0.70), P = 0.002].ConclusionAmong patients with NSCLC and PD-L1 expression of ≥50% treated with first-line pembrolizumab, clinical outcomes are significantly improved in NSCLCs with a PD-L1 expression of ≥90%. These findings have implications for treatment selection as well as for clinical trial interpretation and design.     

Pembrolizumab monotherapy for previously treated metastatic triple-negative breast cancer: cohort A of the phase II KEYNOTE-086 study

BackgroundTreatment options for previously treated metastatic triple-negative breast cancer (mTNBC) are limited. In cohort A of the phase II KEYNOTE-086 study, we evaluated pembrolizumab as second or later line of treatment for patients with mTNBC.Patients and methodsEligible patients had centrally confirmed mTNBC, ≥1 systemic therapy for metastatic disease, prior treatment with anthracycline and taxane in any disease setting, and progression on or after the most recent therapy. Patients received pembrolizumab 200 mg intravenously every 3 weeks for up to 2 years. Primary end points were objective response rate in the total and PD-L1–positive populations, and safety. Secondary end points included duration of response, disease control rate (percentage of patients with complete or partial response or stable disease for ≥24 weeks), progression-free survival, and overall survival.ResultsAll enrolled patients (N = 170) were women, 61.8% had PD-L1–positive tumors, and 43.5% had received ≥3 previous lines of therapy for metastatic disease. ORR (95% CI) was 5.3% (2.7–9.9) in the total and 5.7% (2.4–12.2) in the PD-L1–positive populations. Disease control rate (95% CI) was 7.6% (4.4–12.7) and 9.5% (5.1–16.8), respectively. Median duration of response was not reached in the total (range, 1.2+–21.5+) and in the PD-L1–positive (range, 6.3–21.5+) populations. Median PFS was 2.0 months (95% CI, 1.9–2.0), and the 6-month rate was 14.9%. Median OS was 9.0 months (95% CI, 7.6–11.2), and the 6-month rate was 69.1%. Treatment-related adverse events occurred in 103 (60.6%) patients, including 22 (12.9%) with grade 3 or 4 AEs. There were no deaths due to AEs.ConclusionsPembrolizumab monotherapy demonstrated durable antitumor activity in a subset of patients with previously treated mTNBC and had a manageable safety profile.Clinical trial registrationClinicalTrials.gov, NCT02447003     

Phase 1 Expansion Cohort of Ramucirumab Plus Pembrolizumab in Advanced Treatment-Naive NSCLC

IntroductionData of first-line ramucirumab plus pembrolizumab treatment of programmed death-ligand 1 (PD-L1)–positive NSCLC (cohort E) are reported (NCT02443324).MethodsIn this multicenter, open-label phase 1a/b trial, patients received ramucirumab 10 mg/kg and pembrolizumab 200 mg every 21 days for up to 35 cycles. PD-L1 positivity was defined as tumor proportion score (TPS) greater than or equal to 1%. Exploratory NanoString biomarker analyses included three T-cell signatures (T-cell–inflamed, Gajewski, and effector T cells) and CD274 gene expression.ResultsCohort E included 26 patients. Treatment-related adverse events of any grade occurred in 22 patients (84.6%). Treatment-related adverse events of grade greater than or equal to 3 were reported in 11 patients (42.3%); the most frequent was hypertension (n = 4, 15.4%). Objective response rate was 42.3% in the treated population and 56.3% and 22.2% for patients with high (TPS ≥ 50%) and lower levels (TPS 1%–49%) of PD-L1 expression, respectively. Median progression-free survival (PFS) in the treated population was 9.3 months, and 12-month and 18-month PFS rates were 45% each. Median PFS was not reached in patients with PD-L1 TPS greater than or equal to 50% and was 4.2 months in patients with PD-L1 TPS 1% to 49%. Median overall survival was not reached in the treated population, and 12-month and 18-month overall survival rates were 73% and 64%, respectively. Biomarker data suggested a positive association among clinical response, three T-cell signatures, CD274 gene expression, and PD-L1 immunohistochemistry.ConclusionsFirst-line therapy with ramucirumab plus pembrolizumab has a manageable safety profile in patients with NSCLC, and the efficacy signal seems to be strongest in tumors with high PD-L1 expression.     

Five-year survival outcomes for patients with advanced melanoma treated with pembrolizumab in KEYNOTE-001

BackgroundPembrolizumab demonstrated robust antitumor activity and safety in the phase Ib KEYNOTE-001 study (NCT01295827) of advanced melanoma. Five-year outcomes in all patients and treatment-naive patients are reported herein. Patients whose disease progressed following initial response and who received a second course of pembrolizumab were also analyzed.Patients and methodsPatients aged ≥18 years with previously treated or treatment-naive advanced/metastatic melanoma received pembrolizumab 2 mg/kg every 3 weeks, 10 mg/kg every 3 weeks, or 10 mg/kg every 2 weeks until disease progression, intolerable toxicity, or patient/investigator decision to withdraw. Kaplan–Meier estimates of overall survival (OS) and progression-free survival (PFS) were calculated. Objective response rate and PFS were based on immune-related response criteria by investigator assessment (data cut-off, September 1, 2017).ResultsKEYNOTE-001 enrolled 655 patients with melanoma; median follow-up was 55 months. Estimated 5-year OS was 34% in all patients and 41% in treatment-naive patients; median OS was 23.8 months (95% CI, 20.2–30.4) and 38.6 months (95% CI, 27.2–not reached), respectively. Estimated 5-year PFS rates were 21% in all patients and 29% in treatment-naive patients; median PFS was 8.3 months (95% CI, 5.8–11.1) and 16.9 months (95% CI, 9.3–35.5), respectively. Median response duration was not reached; 73% of all responses and 82% of treatment-naive responses were ongoing at data cut-off; the longest response was ongoing at 66 months. Four patients [all with prior response of complete response (CR)] whose disease progressed during observation subsequently received second-course pembrolizumab. One patient each achieved CR and partial response (after data cut-off). Treatment-related AEs (TRAEs) occurred in 86% of patients and resulted in study discontinuation in 7.8%; 17% experienced grade 3/4 TRAE.ConclusionsThis 5-year analysis of KEYNOTE-001 represents the longest follow-up for pembrolizumab to date and confirms the durable antitumor activity and tolerability of pembrolizumab in advanced melanoma.Clinical Trial RegistryClinicalTrials.gov, NCT01295827.     

Pembrolizumab After Two or More Lines of Previous Therapy in Patients With Recurrent or Metastatic SCLC: Results From the KEYNOTE-028 and KEYNOTE-158 Studies

IntroductionPembrolizumab has shown clinical benefit in patients with previously treated recurrent or metastatic SCLC in the phase 1b multicohort study KEYNOTE-028 (NCT02054806) and the phase 2 multicohort study KEYNOTE-158 (NCT02628067). We present a pooled analysis of patients from KEYNOTE-028 and KEYNOTE-158 who had received two or more lines of previous therapy for SCLC.MethodsEligible patients were aged 18 years and above, had histologically or cytologically confirmed incurable recurrent or metastatic SCLC, had an Eastern Cooperative Oncology Group performance status of 1 and below, and had received two or more lines of previous therapy. Patients in KEYNOTE-028 were required to have a programmed death ligand 1 (PD-L1)–positive tumor. Patients received pembrolizumab (10 mg/kg every 2 weeks in KEYNOTE-028 or 200 mg every 3 weeks in KEYNOTE-158) for up to 2 years. The primary end point was objective response rate per Response Evaluation Criteria in Solid Tumors version 1.1, which is presented here per independent review.ResultsEighty-three patients who had received two or more lines of previous therapy (KEYNOTE-028, n = 19; KEYNOTE-158, n = 64) were included. Median follow-up duration was 7.7 (range, 0.5–48.7) months. Objective response rate was 19.3% (95% confidence interval: 11.4–29.4); two patients had complete response (one with a PD-L1–positive tumor), and 14 patients had partial response (13 with PD-L1–positive tumors). The median duration of response was not reached (range, 4.1‒35.8+ mo; plus sign indicates ongoing response); 61% of responders had responses lasting 18 months or longer. Fifty-one patients (61.4%) experienced any-grade treatment-related adverse events; eight patients (9.6%) had grade 3 or higher events.ConclusionsPembrolizumab exhibited durable antitumor activity in a subset of patients with recurrent or metastatic SCLC who had undergone two or more previous lines of therapy, regardless of PD-L1 expression. Pembrolizumab was well tolerated.     

Pembrolizumab plus chemotherapy in Japanese patients with metastatic squamous non-small-cell lung cancer in KEYNOTE-407

The global phase III KEYNOTE-407 (NCT02775435) trial showed that pembrolizumab plus chemotherapy prolonged overall and progression-free survival (OS/PFS) versus placebo plus chemotherapy in patients with metastatic squamous non-small-cell lung cancer (NSCLC). We present outcomes of patients from Japan enrolled in KEYNOTE-407. Patients were randomized 1:1 to receive pembrolizumab 200 mg or placebo with paclitaxel 200 mg/m² every 3 weeks (Q3W) or nab-paclitaxel 100 mg/m² (weekly) plus carboplatin area under the concentration-time curve of 6 mg/mL/min Q3W for four cycles, followed by pembrolizumab or placebo Q3W for a total of 35 cycles. Primary end-points were OS and PFS per RECIST version 1.1 by blinded independent central review. Fifty patients were randomized at Japanese sites (pembrolizumab plus chemotherapy, n = 22; placebo plus chemotherapy, n = 28). Median follow-up time at data cut-off (May 9, 2019) was 15.1 (range, 0.5–24.0) months. Median OS (95% confidence interval [CI]) was 17.3 (12.5–not reached) versus 11.0 (8.6–19.5) months in the pembrolizumab plus chemotherapy versus placebo plus chemotherapy group (hazard ratio [HR] 0.56; 95% CI, 0.27–1.15). Median PFS (95% CI) was 8.3 (6.1–13.0) versus 7.2 (3.9–8.8) months (HR 0.65; 95% CI, 0.35–1.23). Grade 3–5 adverse events (AEs) occurred in 86% and 75% of patients, respectively. There were three fatal AEs, two of which were treatment-related (one from each treatment group, pneumonitis and pulmonary hemorrhage). Efficacy and safety outcomes were consistent with the global study and support the use of pembrolizumab plus chemotherapy in Japanese patients with metastatic squamous NSCLC.     

Pembrolizumab monotherapy for previously untreated,PD-L1-positive,metastatic triple-negative breast cancer: cohort B of the phase II KEYNOTE-086 study

BackgroundStandard first-line treatment of metastatic triple-negative breast cancer (mTNBC) is chemotherapy. However, outcomes are poor, and new treatment options are needed. In cohort B of the phase II KEYNOTE-086 study, we evaluated pembrolizumab as first-line therapy for patients with PD-L1-positive mTNBC.Patients and methodsEligible patients had centrally confirmed mTNBC, no prior systemic anticancer therapy for metastatic disease, measurable disease at baseline per RECIST v1.1 by central review, no radiographic evidence of central nervous system metastases, and a tumor PD-L1 combined positive score ≥1. Patients received pembrolizumab 200 mg intravenously every 3 weeks for up to 2 years. The primary end point was safety. Secondary end points included objective response rate, disease control rate (percentage of patients with complete or partial response or stable disease for ≥24 weeks), duration of response, progression-free survival and overall survival.ResultsAll 84 patients enrolled were women, and 73 (86.9%) received prior (neo)adjuvant therapy. Fifty-three (63.1%) patients had treatment-related adverse events (AEs), including 8 patients (9.5%) with grade 3 severity; no patients experienced grade 4 AEs or died because of treatment-related AEs. Four patients had a complete response and 14 had a partial response, for an objective response rate of 21.4% (95% CI 13.9–31.4). Of the 13 patients with stable disease, 2 had stable disease lasting ≥24 weeks, for a disease control rate of 23.8% (95% CI 15.9–34.0). At data cut-off, 8 of 18 (44.4%) responses were ongoing, and median duration of response was 10.4 months (range 4.2 to 19.2+). Median progression-free survival was 2.1 months (95% CI 2.0–2.2), and median overall survival was 18.0 months (95% CI 12.9–23.0).ConclusionsPembrolizumab monotherapy had a manageable safety profile and showed durable antitumor activity as first-line therapy for patients with PD-L1-positive mTNBC.Clinical trial registrationClinicalTrials.gov, NCT02447003.