Search

Objective To evaluate safety, tolerability, and antitumor activity of pembrolizumab monotherapy in patients with programmed death ligand 1 (PD-L1)–expressing advanced ovarian cancer enrolled in the multicohort, phase Ib KEYNOTE-028 trial. Methods Key inclusion criteria were age ≥18 years; advanced ovarian epithelial, fallopian tube, or primary peritoneal carcinoma; failure of previous therapy; and tumor PD-L1 positivity. Patients received pembrolizumab (10 mg/kg every 2 weeks) for ≤24 months or until disease progression/intolerable toxicity. Tumor response was assessed per RECIST v1.1 (investigator review). Adverse events (AEs) were graded using CTCAE version 4.0. Primary end point was confirmed objective response rate (ORR) per RECIST v1.1 (investigator review); data cutoff date was February 20, 2017. Results Twenty-six patients (median age, 57.5 years) with PD-L1–positive advanced metastatic ovarian cancer received pembrolizumab; 38.5% had metastatic disease, and 73.1% previously received ≥3 lines of therapy. Treatment-related AEs (TRAEs) occurred in 19 (73.1%) patients, most commonly arthralgia (19.2%), nausea (15.4%), and pruritus (15.4%). One grade 3 TRAE (increased plasma transaminase level) occurred. No deaths and no treatment discontinuations due to TRAEs occurred. After a median follow-up duration of 15.4 months, ORR was 11.5% (1 complete response, 2 partial responses); 7 patients (26.9%) achieved stable disease. Median progression-free and overall survival were 1.9 (95% CI, 1.8–3.5) and 13.8 (95% CI, 6.7–18.8) months, respectively. Conclusion Pembrolizumab conferred durable antitumor activity with manageable safety and toxicity in patients with advanced PD-L1–positive ovarian cancer and is under further investigation in an ongoing phase II trial, KEYNOTE-100.

Background Safety and efficacy of pembrolizumab, a humanized programmed death 1 monoclonal antibody, was assessed in KEYNOTE-028, a multicohort, phase Ib trial for patients with programmed death ligand 1 (PD-L1)-positive advanced solid tumors. We report results for the cohort of patients with advanced anal carcinoma. Patients and methods Patients with PD-L1-positive tumors (≥1%) received intravenous pembrolizumab 10 mg/kg once every 2 weeks for up to 2 years or until confirmed progression or unacceptable toxicity. Response was assessed every 8 weeks for the first 6 months and every 12 weeks thereafter per Response Evaluation Criteria In Solid Tumors, version 1.1. Primary endpoints were safety and overall response rate per investigator review. Secondary endpoints included progression-free survival, overall survival, and response duration. Data cutoff date was 1 July 2015. Results Of the 43 patients with advanced anal carcinoma evaluable for PD-L1 expression, 32 (74%) had PD-L1-positive tumors as assessed with the 22C3 prototype assay, of whom 25 were enrolled between April and September 2014. Sixteen patients (64%) experienced treatment-related adverse events; the most common ones were diarrhea and fatigue in four patients (16%) each and nausea in three patients (12%). There were no treatment-related deaths or discontinuations as of the data cutoff date. Among the 24 patients with squamous cell carcinoma histology, four had confirmed partial response, for an overall response rate of 17% [95% confidence interval (CI), 5%–37%) and 10 (42%) had confirmed stable disease, for a disease control rate of 58%. One additional patient with non-squamous histology had confirmed stable disease. Conclusion In this population of patients with PD-L1-positive advanced squamous cell anal carcinoma, pembrolizumab demonstrated a manageable safety profile and encouraging antitumor activity. These data support further study of pembrolizumab for this patient population. ClinicalTrials.gov NCT02054806.

Purpose The safety and efficacy of pembrolizumab, a humanized monoclonal antibody against programmed death 1 (PD-1), were assessed in patients with programmed death ligand 1 (PD-L1)–expressing extensive-stage small-cell lung cancer (SCLC) in the multicohort, phase Ib open-label KEYNOTE-028 study ( ClinicalTrials.gov identifier: NCT02054806). Methods Patients with SCLC received pembrolizumab 10 mg/kg every 2 weeks for 24 months or until disease progression or intolerable toxicity occurred. PD-L1 expression was assessed by immunohistochemistry. PD-L1–positive patients had membranous PD-L1 expression in ≥ 1% of tumor and associated inflammatory cells or positive staining in stroma. Response was assessed by investigator per Response Evaluation Criteria in Solid Tumors version 1.1 every 8 weeks for the first 6 months and every 12 weeks thereafter. Adverse events (AEs) were reported per the National Cancer Institute Common Terminology Criteria for Adverse Events, version 4.0. Primary end points were safety, tolerability, and objective response rate (ORR). Secondary end points included progression-free survival, overall survival, and duration of response. Results Twenty-four patients with PD-L1–expressing SCLC were enrolled and received at least one pembrolizumab dose. At the data cutoff date (June 20, 2016), the median follow-up duration was 9.8 months (range, 0.5 to 24 months). All 24 patients experienced AEs; the most common were asthenia (n = 7), fatigue (n = 7), and cough (n = 6). Two patients experienced grade 3 to 5 treatment-related AEs: one patient had elevated bilirubin, and one patient had asthenia, grade 5 colitis, and intestinal ischemia. One patient had a complete response, and seven patients had partial responses, resulting in an ORR of 33% (95% CI, 16% to 55%). Conclusion The safety of pembrolizumab was consistent with the known safety profile in other tumor types. Pembrolizumab demonstrated promising antitumor activity in patients with pretreated, PD-L1–expressing SCLC.

Summary Background Malignant pleural mesothelioma is a highly aggressive cancer with poor prognosis and few treatment options following progression on platinum-containing chemotherapy. We assessed the safety and efficacy of pembrolizumab (an anti-programmed cell death receptor 1 [PD-1] antibody) in advanced solid tumours expressing programmed cell death ligand 1 (PD-L1) and report here on the interim analysis of the malignant pleural mesothelioma cohort. Methods Previously treated patients with PD-L1-positive malignant pleural mesothelioma were enrolled from 13 centres in six countries. Patients received pembrolizumab (10 mg/kg every 2 weeks) for up to 2 years or until confirmed progression or unacceptable toxicity. Key eligibility criteria included measurable disease, failure of standard therapy, and Eastern Cooperative Oncology Group performance status of 0 or 1. PD-L1 positivity was defined as expression in 1% or more of tumour cells by immunohistochemistry. Response was assessed based on investigator review using the Response Evaluation Criteria in Solid Tumors (RECIST; version 1.1). Primary endpoints were safety and tolerability, analysed in the all-patients-as-treated population, and objective response, analysed for the full-analysis set. This trial is registered with ClinicalTrials.gov, number NCT02054806, and is ongoing but not recruiting participants. Findings As of June 20, 2016, 25 patients received pembrolizumab. 16 (64%) patients reported a treatment-related adverse event; the most common adverse event were fatigue (six [24%]), nausea (six [24%]), and arthralgia (five [20%]). Five (20%) patients reported grade 3 treatment-related adverse events. Three (12%) patients required dose interruption because of immune-related adverse events: one (4%) of 25 each had grade 3 rhabdomyolysis and grade 2 hypothyroidism; grade 3 iridocyclitis, grade 1 erythema multiforme, and grade 3 erythema; and grade 2 infusion-related reaction. No treatment-related deaths or discontinuations occurred. Five (20%) patients had a partial response, for an objective response of 20% (95% CI 6·8–40·7), and 13 (52%) of 25 had stable disease. Responses were durable (median response duration 12·0 months [95% CI 3·7 to not reached]); two patients remained on treatment at data cutoff. Interpretation Pembrolizumab appears to be well tolerated and might confer anti-tumour activity in patients with PD-L1-positive malignant pleural mesothelioma. Response durability and efficacy in this patient population warrants further investigation. Funding Merck.

5513 Background: Overexpression of the PD-1 ligand PD-L1 has been demonstrated in ovarian cancer and may hinder an effective antitumor immune response. A preliminary analysis of the ovarian cancer cohort of the KEYNOTE-028 study (NCT02054806) suggested that the PD-1 inhibitor pembrolizumab has promising antitumor activity in pts with PD-L1+advanced ovarian cancer. An updated analysis of the ovarian cancer cohort based on 15.5 months of follow-up is presented. Methods: Key eligibility criteria for the ovarian cohort of this nonrandomized, multicohort phase Ib trial were advanced ovarian epithelial, fallopian tube, or primary peritoneal carcinoma; failure of prior therapy; PD-L1 positivity defined as membranous staining on ≥1% of tumor and associated inflammatory cells or positive staining in stroma; and ECOG PS 0/1. Pembrolizumab (10 mg/kg every 2 wk) was given for ≤2 y or until confirmed progression/unacceptable toxicity. Response was assessed per RECIST v1.1 by investigators every 8 wk for the first 6 mo and every 12 wk thereafter. Primary end points were safety, tolerability, and confirmed ORR. Results: 26 pts (median age, 57.5 y) were enrolled; 61.5% were white, 38.5% received ≥5 therapies for recurrent/metastatic disease, and 53.8% received prior neoadjuvant/adjuvant therapies. As of the October 10, 2016, data cutoff, the median follow-up duration was 15.5 mo (range, 2.4-30.8 mo). 1 pt had a complete response and 2 had partial responses; 6 pts had stable disease as best response. ORR was 11.5% (95% CI, 2.4%-30.2%). Tumor reduction was observed in 6/26 (23.1%); all 3 patients who responded completed 2 years of treatment. Median duration of response was not reached (range, 24.9+ to 26.5+ mo). Median (95% CI) PFS and OS were 1.9 mo (1.8-3.2 mo) and 13.1 mo (6.7-17.5 mo) respectively. Treatment-related AEs occurred in 73.1% of pts, and the most common were arthralgia (19.2%), nausea (15.4%), pruritus (15.4%), rash (11.5%), and diarrhea (11.5%). 1 patient had a grade 3 drug-related adverse event (transaminase increased). Conclusions: With 15.5 mo of follow-up, pembrolizumab continued to be well tolerated and demonstrated durable antitumor activity in pts with advanced ovarian cancer. Clinical trial information: NCT02054806.