GITR agonistic stimulation enhances the anti-tumor immune response in a mouse model of ESCC.

Esophageal cancer is a significant health burden in the United States and worldwide and is the 8th leading cause of cancer-related death. Over 90% of esophageal cancers are squamous cell cancers (ESCC). Despite the development of new therapies, the overall 5-year survival rate remains lower than 20%. Recent clinical trials of immunotherapy approaches in ESCC have shown that blocking PD-1/PD-L1 interactions can reduce tumor burden and increase survival, but this only occurs in a fraction of patients. This emphasizes the need for additional therapeutic options to improve overall response rates, duration of response, and overall survival. Glucocorticoid-induced TNFR-related protein (GITR) stimulation has emerged as a promising immunotherapy target, as its stimulation appears to promote tumor regression. In this study, we evaluated the consequences of GITR agonistic stimulation with the DTA-1 antibody (anti-GITR agonist) on esophageal squamous cell carcinoma (ESCC) progression. Increased expression of GITR was observed in esophageal tumors from ESCC patients in comparison to normal adjacent tissue and in a mouse model of ESCC. 100% of mice treated with 4-NQO/IgG control antibody developed invasive squamous cell carcinoma. Less advanced esophageal tumors were seen in mice treated with 4-NQO/anti-GITR agonist compared to 4-NQO/IgG treatment. 4-NQO/anti-GITR agonist-treated mice demonstrated a significant increase in mucosal CTL/Treg ratios as well as decreased gene expression profiles of pathways related to esophageal squamous cell carcinogenesis. Thus, GITR agonism merits further study as a treatment strategy for ESCC patients.

Safety, Efficacy, and Biomarker Results from a Phase Ib Study of the Anti-DKK1 Antibody DKN-01 in Combination with Pembrolizumab in Advanced Esophagogastric Cancers.

Therapeutic combinations targeting innate and adaptive immunity and predictive biomarkers of response in esophagogastric cancer (EGC) are needed. We assessed safety and clinical utility of DKN-01 (a novel DKK1-neutralizing IgG4 antibody) combined with pembrolizumab and retrospectively determined DKK1 tumoral expression as a biomarker. Patients with advanced EGC received intravenous DKN-01 (150 or 300 mg) on days 1 and 15 with pembrolizumab 200 mg on day 1 in 21-day cycles. Clinical response was assessed by RECIST v1.1. Association of tumoral DKK1 mRNA expression (H-score: high ≥ upper-tertile, low < upper-tertile) with response was assessed with PD-L1 levels as a covariate. Sixty-three patients received DKN-01 150 mg (n = 2) or 300 mg (n = 61) plus pembrolizumab. Common adverse events were fatigue, anemia, blood alkaline phosphatase elevation, aspartate aminotransferase elevation, and hyponatremia. Among evaluable anti-PD-1/PD-L1-naïve patients receiving DKN-01 300 mg and pembrolizumab, objective response rate (ORR) was 11.4% (5/44) and 18.5% (5/27) in patients with gastroesophageal junction or gastric cancer (GEJ/GC). Among response-evaluable anti-PD-1/PD-L1-naïve patients with GEJ/GC and known tumoral DKK1 expression, ORR was 50% in DKK1-high and 0% in DKK1-low patients, median PFS was 22.1 vs. 5.9 weeks (HR, 0.24; 95% CI, 0.08-0.67), respectively, and median OS was 31.6 weeks vs. 17.4 weeks (HR, 0.41; 95% CI, 0.16-1.07), respectively. Association of DKK1 expression with PFS was independent of PD-L1 expression (adjusted HR, 0.21; 95% CI, 0.06-0.69). DKN-01 combined with pembrolizumab was well tolerated with no new safety signals. Antitumor activity was enriched in anti-PD-1/PD-L1-naïve patients with GEJ/GC whose tumors expressed high DKK1.

CALGB 80403 (Alliance)/E1206: A Randomized Phase II Study of Three Chemotherapy Regimens Plus Cetuximab in Metastatic Esophageal and Gastroesophageal Junction Cancers.

PURPOSE: To determine the optimal chemotherapy backbone for testing in future US cooperative group studies for metastatic esophageal and gastroesophageal junction cancers. Cetuximab was added to each treatment arm based on promising preclinical data. PATIENTS AND METHODS: Patients with previously untreated metastatic esophageal or gastroesophageal junction cancer were randomly assigned at a one-to-one-to-one ratio to epirubicin, cisplatin, and continuous-infusion fluorouracil (ECF), irinotecan plus cisplatin (IC), or FOLFOX (oxaliplatin, leucovorin, and bolus and infusional fluorouracil). All treatment programs included cetuximab once per week. The primary end point was response rate. Secondary outcomes included overall survival, progression-free survival, time to treatment failure, and safety. As prespecified, primary and secondary analyses were conducted only among patients with adenocarcinoma. RESULTS: This study randomly assigned 245 patients, including 222 with adenocarcinoma. Among patients with adenocarcinoma, response rate was 60.9% (95% CI, 47.9 to 72.8) for ECF plus cetuximab, 45.0% (95% CI, 33.0 to 57.0) for IC plus cetuximab, and 54.3% (95% CI, 42.0 to 66.2) for FOLFOX plus cetuximab. Median overall survival was 11.6, 8.6, and 11.8 months; median progression-free survival was 7.1, 4.9, and 6.8 months; and median time to treatment failure was 5.6, 4.3, and 6.7 months for each of these arms, respectively. FOLFOX plus cetuximab required fewer treatment modifications compared with ECF plus cetuximab and IC plus cetuximab (P = .013), and fewer patients were removed from treatment because of an adverse event or experienced treatment-related death. CONCLUSION: In combination with cetuximab, ECF and FOLFOX had similar efficacy, but FOLFOX was better tolerated. Although differences were nonsignificant, IC plus cetuximab seemed to be the least effective and most toxic of the three regimens tested.