PURPOSE Biomarkers that can predict response to anti–programmed cell death 1 (PD-1) therapy across multiple tumor types include a T-cell–inflamed gene-expression profile (GEP), programmed death ligand 1 (PD-L1) expression, and tumor mutational burden (TMB). Associations between these biomarkers and the clinical efficacy of pembrolizumab were evaluated in a clinical trial that encompassed 20 cohorts of patients with advanced solid tumors. METHODS KEYNOTE-028 ( ClinicalTrials.gov identifier: NCT02054806) is a nonrandomized, phase Ib trial that enrolled 475 patients with PD-L1–positive advanced solid tumors who were treated with pembrolizumab 10 mg/kg every 2 weeks for 2 years or until confirmed disease progression or unacceptable toxicity occurred. The primary end point was objective response rate (ORR; by RECIST v1.1, investigator review). Secondary end points included safety, progression-free survival (PFS), and overall survival (OS). Relationships between T-cell–inflamed GEP, PD-L1 expression, and TMB and antitumor activity were exploratory end points. RESULTS ORRs (with 95% CIs) ranged from 0% (0.0% to 14.2%) in pancreatic cancer to 33% (15.6% to 55.3%) in small-cell lung cancer. Across cohorts, median (95% CI) PFS ranged from 1.7 months (1.5 to 2.9 months) to 6.8 months (1.9 to 14.1 months) in pancreatic and thyroid cancers, respectively, and median OS from 3.9 months (2.8 to 5.5 months) to 21.1 months (9.1 to 22.4 months) in vulvar and carcinoid tumors, respectively. Higher response rates and longer PFS were demonstrated in tumors with higher T-cell–inflamed GEP, PD-L1 expression, and/or TMB. Correlations of TMB with GEP and PD-L1 were low. Response patterns indicate that patients with tumors that had high levels of both TMB and inflammatory markers (GEP or PD-L1) represent a population with the highest likelihood of response. Safety was similar and consistent with prior pembrolizumab reports. CONCLUSION A T-cell–-inflamed GEP, PD-L1 expression, and TMB predicted response to pembrolizumab in multiple tumor types. These biomarkers (alone/in combination) may help identify patients who have a higher likelihood of response to anti–PD-1 therapies across a broad spectrum of cancers.

Purpose To establish the safety profile and antitumor activity of the anti-programmed death 1 receptor monoclonal antibody, pembrolizumab, in patients with recurrent or metastatic nasopharyngeal carcinoma (RM-NPC) that expressed programmed death-ligand 1 (PD-L1). Patients and Methods KEYNOTE-028 (NCT02054806) is a nonrandomized, multicohort, phase Ib trial of pembrolizumab in patients with PD-L1-positive advanced solid tumors. Key eligibility criteria for the NPC cohort included unresectable or metastatic disease, failure on prior standard therapy, and PD-L1 expression in 1% or more of tumor cells or tumor-infiltrating lymphocytes. Patients received pembrolizumab 10 mg/kg every 2 weeks up to 2 years or until disease progression or unacceptable toxicity. Primary end point was objective response rate (ORR) per investigator review. Tumor response was assessed according to Response Evaluation Criteria in Solid Tumors (RECIST; version 1.1) every 8 weeks for the first 6 months and every 12 weeks thereafter. Results Twenty-seven patients received pembrolizumab. Median age was 52.0 years (range, 18 to 68 years); 92.6% received prior therapies for RM-NPC; 70.4% had received three or more therapies. Partial response and stable disease were observed in seven and 14 patients, respectively, for an ORR of 25.9% (95% CI, 11.1 to 46.3) over a median follow-up of 20 months. ORR by central review was similar (26.3%). Drug-related adverse events that occurred in 15% or more of patients included rash (25.9%), pruritus (25.9%), pain (22.2%), hypothyroidism (18.5%), and fatigue (18.5%). Grade ≥ 3 drug-related adverse events occurred in eight patients (29.6%), and there was one drug-related death (sepsis). As of the data cutoff (June 20, 2016), two patients remained on pembrolizumab treatment. Conclusion Pembrolizumab demonstrated antitumor activity and a manageable safety profile in patients with RM-NPC.

Purpose The KEYNOTE-028 trial ( ClinicalTrials.gov identifier: NCT02054806) was designed to assess the safety and efficacy of pembrolizumab in 20 programmed death ligand 1-positive, advanced solid tumor cohorts. Here, we present the results from the cohort of patients with advanced cervical cancer. Methods Patients were treated with pembrolizumab 10 mg/kg every 2 weeks for up to 24 months. Response was assessed every 8 weeks for the first 6 months and every 12 weeks thereafter. The primary end point was overall response rate per Response Evaluation Criteria in Solid Tumors, version 1.1, by investigator review. Safety was a secondary end point. Results Twenty-four patients were enrolled in the cervical cancer cohort. The median age was 42 years (range, 26 to 62 years), 22 patients (92%) had received prior radiation therapy, and 15 patients (63%) had received two or more lines of therapy, including bevacizumab (10 of 24 patients), for advanced disease. At the data cutoff, median follow-up duration was 11.0 months (range, 1.3 to 32.2 months). Overall response rate was 17% (95% CI, 5% to 37%); four patients (17%) achieved a confirmed partial response, and three patients (13%) had stable disease. Median duration of response for the four patients who achieved a partial response was 5.4 months (4.1 to 7.5 months). Treatment related adverse events (AEs) were experienced by 18 patients (75%); only rash (n = 5; 21%) and pyrexia (n = 4; 17%) and occurred in ≥ 10% of patients. Five patients experienced grade 3 treatment-related AEs. No grade 4 treatment-related AEs or deaths were observed. Conclusion In patients with programmed death ligand 1-positive advanced cervical cancer, pembrolizumab demonstrated antitumor activity and exhibited a safety profile consistent with that seen in other tumor types.