Pembrolizumab in patients with programmed death ligand 1-positive advanced ovarian cancer: Analysis of KEYNOTE-028.

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.

Pembrolizumab in Patients With Extensive-Stage Small-Cell Lung Cancer: Results From the Phase Ib KEYNOTE-028 Study.

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.

Clinical safety and activity of pembrolizumab in patients with malignant pleural mesothelioma (KEYNOTE-028): preliminary results from a non-randomised, open-label, phase 1b trial.

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.

Antitumor activity in RAS-driven tumors by blocking AKT and MEK.

PURPOSE: KRAS is the most commonly mutated oncogene in human tumors. KRAS-mutant cells may exhibit resistance to the allosteric MEK1/2 inhibitor selumetinib (AZD6244; ARRY-142886) and allosteric AKT inhibitors (such as MK-2206), the combination of which may overcome resistance to both monotherapies. EXPERIMENTAL DESIGN: We conducted a dose/schedule-finding study evaluating MK-2206 and selumetinib in patients with advanced treatment-refractory solid tumors. Recommended dosing schedules were defined as MK-2206 at 135 mg weekly and selumetinib at 100 mg once daily. RESULTS: Grade 3 rash was the most common dose-limiting toxicity (DLT); other DLTs included grade 4 lipase increase, grade 3 stomatitis, diarrhea, and fatigue, and grade 3 and grade 2 retinal pigment epithelium detachment. There were no meaningful pharmacokinetic drug-drug interactions. Clinical antitumor activity included RECIST 1.0-confirmed partial responses in non-small cell lung cancer and low-grade ovarian carcinoma. CONCLUSION: Responses in KRAS-mutant cancers were generally durable. Clinical cotargeting of MEK and AKT signaling may be an important therapeutic strategy in KRAS-driven human malignancies (Trial NCT number NCT01021748).