Efficacy of Pembrolizumab Monotherapy in Japanese Patients with Advanced Gastric or Gastroesophageal Junction Cancer.

PURPOSE: Pembrolizumab demonstrated antitumor activity in programmed death ligand 1 positive (combined positive score (CPS) ≥ 1) gastric/gastroesophageal junction cancer in KEYNOTE-059 (third line or beyond), KEYNOTE-061 (second line), and KEYNOTE-062 (first line). We characterized efficacy and safety of pembrolizumab monotherapy in Japanese patients across several lines of therapy in these studies. METHODS: This analysis was conducted in 34 patients from KEYNOTE-059 cohort 1 (all pembrolizumab), including 13 patients with CPS ≥ 1, 65 patients with CPS ≥ 1 from KEYNOTE-061 (pembrolizumab, n = 27; chemotherapy, n = 38), and 70 patients with CPS ≥ 1 from KEYNOTE-062 (pembrolizumab, n = 38; chemotherapy, n = 32). Overall survival (OS), progression-free survival (PFS), objective response rate (ORR), and safety were evaluated. RESULTS: In KEYNOTE-059, ORR with pembrolizumab was 9%, median PFS was 2 months, and median OS was 10 months. In KEYNOTE-061, median OS was 12 months with pembrolizumab versus 10 months with chemotherapy (hazard ratio (HR), 0.67; 95% confidence interval (CI), 0.39-1.15). Median PFS (pembrolizumab vs. chemotherapy) was 2 months versus 4 months (HR, 1.21; 95% CI, 0.69-2.13); ORR was 7% versus 18%. In KEYNOTE-062, median OS was 20 months with pembrolizumab versus 18 months with chemotherapy (HR, 0.76; 95% CI, 0.43-1.33). Median PFS (pembrolizumab vs. chemotherapy) was 6 months versus 7 months (HR, 1.03; 95% CI, 0.61-1.74); ORR was 29% versus 34%. CONCLUSIONS: The current analysis provides valuable information that anti-PD-1 therapies are worthy of further assessment for gastric cancer. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02335411 (KEYNOTE-059), NCT02370498 (KEYNOTE-061), and NCT02494583 (KEYNOTE-062).

Pembrolizumab or pembrolizumab plus chemotherapy versus standard of care chemotherapy in patients with advanced gastric or gastroesophageal junction adenocarcinoma: Asian subgroup analysis of KEYNOTE-062.

OBJECTIVE: First-line pembrolizumab with/without chemotherapy versus chemotherapy was evaluated in programmed death ligand 1 combined positive score ≥1, locally advanced/unresectable or metastatic gastric cancer/gastrooesophageal junction cancer in the KEYNOTE-062 study. We present results for patients enrolled in Asia. METHODS: Eligible patients were randomly assigned 1:1:1 to pembrolizumab 200 mg, pembrolizumab plus chemotherapy (cisplatin + 5-fluorouracil or capecitabine) or placebo plus chemotherapy Q3W. End points included overall survival (primary) in combined positive score ≥1 and combined positive score ≥10 populations and safety and tolerability (secondary). RESULTS: A total of 187 patients were enrolled in Asia (pembrolizumab, n = 62; pembrolizumab plus chemotherapy, n = 64; chemotherapy, n = 61). Compared with the global population, higher proportions of patients had Eastern Cooperative Oncology Group performance status 0 and a diagnosis of stomach cancer. In the programmed death ligand 1 combined positive score ≥1 population, median overall survival was numerically longer with pembrolizumab versus chemotherapy (22.7 vs 13.8 months; hazard ratio, 0.54; 95% confidence interval, 0.35-0.82) and pembrolizumab plus chemotherapy versus chemotherapy (16.5 vs 13.8 months; hazard ratio, 0.78; 95% confidence interval, 0.53-1.16). In the programmed death ligand 1 combined positive score ≥10 population, median overall survival was also numerically longer with pembrolizumab versus chemotherapy (28.5 vs 14.8 months; hazard ratio, 0.43; 95% confidence interval, 0.21-0.89) and pembrolizumab plus chemotherapy versus chemotherapy (17.5 vs 14.8 months; hazard ratio, 0.86; 95% confidence interval, 0.45-1.64). The grade 3-5 treatment-related adverse event rate was 19.4%, 75.8% and 64.9% for patients receiving pembrolizumab, pembrolizumab plus chemotherapy and chemotherapy, respectively. CONCLUSIONS: This post hoc analysis showed pembrolizumab monotherapy was associated with numerically improved overall survival and a favourable tolerability profile versus chemotherapy in Asians with programmed death ligand 1-positive advanced gastric cancer/gastrooesophageal junction cancer.This study is registered with ClinicalTrials.gov, NCT02494583.

Phase IIb study of pembrolizumab combined with S-1 + oxaliplatin or S-1 + cisplatin as first-line chemotherapy for gastric cancer.

The KEYNOTE-659 study evaluated the efficacy and safety of first-line pembrolizumab plus S-1 and oxaliplatin (SOX) (cohort 1) or S-1 and cisplatin (SP) (cohort 2) for advanced gastric/gastroesophageal junction (G/GEJ) cancer in Japan. Herein, we update the results of cohort 1 and describe the results of cohort 2. This open-label phase IIb study enrolled patients with advanced programmed death-ligand 1 (PD-L1)-positive (combined positive score ≥ 1) human epidermal growth factor receptor 2 (HER2)-negative G/GEJ adenocarcinoma. The primary end-point was the objective response rate (ORR). Other end-points were duration of response (DOR), disease control rate (DCR), progression-free survival (PFS), overall survival (OS), and safety. One hundred patients were enrolled. In cohorts 1 and 2, median follow-up time was 16.9 and 17.1 months; ORR (central review), 72.2% and 80.4%; DOR, 10.6 and 9.5 months; DCR (central review), 96.3% and 97.8%; median PFS (central review), 9.4 and 8.3 months; and median OS, 16.9 and 17.1 months, respectively. Treatment-related adverse events (TRAEs) occurred in all patients, including peripheral sensory neuropathy (94.4%, cohort 1), decreased neutrophil count (82.6%, cohort 2), nausea (59.3% and 60.9% in cohorts 1 and 2), and decreased appetite (61.1% and 60.9% in cohorts 1 and 2). Grade 3 or higher TRAEs were reported by 59.3% (cohort 1) and 78.3% (cohort 2), including decreased platelet count (14.8%, cohort 1) and decreased neutrophil count (52.2%, cohort 2). Pembrolizumab in combination with SOX or SP showed favorable efficacy and safety in patients with PD-L1-positive, HER2-negative G/GEJ adenocarcinoma.

Safety and efficacy of pembrolizumab in combination with S-1 plus oxaliplatin as a first-line treatment in patients with advanced gastric/gastroesophageal junction cancer: Cohort 1 data from the KEYNOTE-659 phase IIb study.

AIM: The KEYNOTE-659 study evaluated the efficacy and safety of pembrolizumab in combination with chemotherapy as the first-line treatment in Japanese patients with advanced gastric/gastroesophageal junction (G/GEJ) cancer. In this paper, we report results from cohort 1 (S-1 plus oxaliplatin [SOX] with pembrolizumab). METHODS: This was a non-randomised, multicentre, open-label phase IIb study in patients with advanced programmed death-ligand 1 (PD-L1)-positive, human epidermal growth factor receptor 2-negative G/GEJ tumours. The primary endpoint was the objective response rate (ORR) assessed by blinded independent central review (BICR). Secondary endpoints were duration of response (DOR), disease control rate (DCR), time to response (TTR), progression-free survival (PFS), overall survival (OS) and safety. Exploratory analyses were performed based on the PD-L1 combined positive score (CPS) status. RESULTS: Fifty-four patients were evaluated. The median follow-up was 10.1 months. ORR and DCR by BICR were 72.2% (95% confidence interval [CI] 58.4-83.5) and 96.3% (95% CI 87.3-99.5), respectively. Median DOR, TTR, PFS and OS were as follows: not reached, 1.5 months, 9.4 months and not reached. The ORR was 73.9% in patients with CPS ≥1 to <10 and 71.0% in those with CPS ≥10. Grade ≥3 treatment-related adverse events (TRAEs) were reported by 57.4% of patients. The most common grade ≥3 TRAEs were decreased platelet count (14.8%), decreased neutrophil count (13.0%), colitis (5.6%) and adrenal insufficiency (5.6%). CONCLUSIONS: SOX with pembrolizumab showed encouraging efficacy and a manageable safety profile for the first-line treatment of advanced G/GEJ cancer. TRIAL REGISTRATION: NCT03382600/JapicCTI-183829.

Safety and efficacy of tigatuzumab plus sorafenib as first-line therapy in subjects with advanced hepatocellular carcinoma: A phase 2 randomized study.

BACKGROUND & AIMS: Tigatuzumab is a humanized monoclonal antibody that acts as a death receptor-5 agonist and exerts tumour necrosis factor-related apoptosis-inducing ligand-like activity. In this phase II study, safety and tolerability of the combination of tigatuzumab and sorafenib was evaluated in patients with advanced hepatocellular carcinoma. METHODS: Adults with advanced hepatocellular carcinoma, measurable disease, and an Eastern Cooperative Oncology Group performance score⩽1 were enrolled. Eligible subjects were randomly assigned 1:1:1 to tigatuzumab (6 mg/kg loading, 2 mg/kg/week maintenance) plus sorafenib 400 mg twice daily; tigatuzumab (6 mg/kg loading, 6 mg/kg/week maintenance) plus sorafenib 400 mg twice daily; or sorafenib 400 mg twice daily. The primary end point was time to progression. Secondary end points included overall survival and safety. RESULTS: 163 subjects were randomized to treatment. Median time to progression was 3.0 months in the tigatuzumab 6/2 mg/kg combination group (p=0.988 vs. sorafenib), 3.9 months in the tigatuzumab 6/6 mg/kg combination group (p=0.586 vs. sorafenib), and 2.8 months in the sorafenib alone group. Median overall survival was 12.2 months in the tigatuzumab 6/6 mg/kg combination group (p=0.659 vs. sorafenib), vs. 8.2 months in both other treatment groups (p=0.303, tigatuzumab 6/2 mg/kg combination vs. sorafenib). The most common treatment-emergent adverse events were palmar-plantar erythrodysesthesia syndrome, diarrhea, and decreased appetite. CONCLUSIONS: Tigatuzumab combined with sorafenib vs. sorafenib alone in adults with advanced hepatocellular carcinoma did not meet its primary efficacy end point, although tigatuzumab plus sorafenib is well tolerated in hepatocellular carcinoma.