Regorafenib in Combination with First-Line Chemotherapy for Metastatic Esophagogastric Cancer.

BACKGROUND: Angiogenesis is critical to gastroesophageal adenocarcinoma growth and metastasis. Regorafenib is a multikinase inhibitor targeting angiogenic and stromal receptor tyrosine kinases. We evaluated whether regorafenib augments the antitumor effect of first-line chemotherapy in metastatic esophagogastric cancer. MATERIALS AND METHODS: Patients with previously untreated metastatic gastroesophageal adenocarcinoma received 5-fluorouracil, leucovorin, and oxaliplatin (mFOLFOX6) every 14 days and regorafenib 160 mg daily on days 4 to 10 of each 14-day cycle. The primary endpoint was 6-month progression-free survival (PFS). To identify predictive biomarkers of outcome, we examined correlations between genomic characteristics of sequenced pretreatment tumors and PFS. RESULTS: Between August 2013 and November 2014, 36 patients with metastatic esophagogastric cancer were accrued to this single-center phase II study (NCT01913639). The most common grade 3-4 treatment-related adverse events were neutropenia (36%), leucopenia (11%) and hypertension (8%). The 6-month PFS was 53% (95% confidence interval [CI], 38%-71%), the objective response rate was 54% (95% CI, 37%-70%), and the disease control rate was 77% (95% CI, 67%-94%). Next-generation sequencing did not identify any genomic alterations significantly correlated with response, and there was no association between homologous recombination deficiency and PFS with platinum-based chemotherapy. CONCLUSION: Regorafenib (one week on-one week off schedule) is well tolerated in combination with first-line FOLFOX but does not improve 6-month PFS relative to historical control. IMPLICATIONS FOR PRACTICE: Prognosis for metastatic esophagogastric cancer remains poor despite modern systemic therapy regimens. This phase II trial indicates that the combination of regorafenib and FOLFOX is well tolerated but does not add to the efficacy of first-line chemotherapy in metastatic esophagogastric cancer. Notably, recently reported data suggest potential synergy between regorafenib and the PD-1 inhibitor nivolumab. As this study demonstrates that regorafenib plus FOLFOX is safe, and combined chemotherapy and immunotherapy show favorable toxicity profiles, future studies combining immunotherapy with regorafenib and chemotherapy may be feasible.

Efficacy of Combined VEGFR1-3, PDGFα/ß, and FGFR1-3 Blockade Using Nintedanib for Esophagogastric Cancer.

PURPOSE: VEGFR2-directed therapy is commonly used to treat metastatic esophagogastric cancer, but disease progresses in most patients within months. Therapeutic resistance is likely mediated in part by co-occurring amplifications of the genes for multiple oncogenic receptor tyrosine kinases (RTK). We therefore tested the efficacy of combined inhibition of VEGFR1-3, PDGFα/ß, and FGFR1-3 using nintedanib. PATIENTS AND METHODS: Patients with metastatic esophagogastric adenocarcinoma and disease progression on first-line chemotherapy were treated with nintedanib 200 mg twice daily. The primary endpoint was progression-free survival (PFS) at 6 months; secondary endpoints included tumor response and safety. Tumor biopsies were profiled by targeted capture next-generation sequencing (NGS) to identify molecular predictors of drug response. RESULTS: The study achieved its primary endpoint; 6 of 32 patients (19%) were progression-free at 6 months. With a median follow-up of 14.5 months among survivors, median overall survival (OS) was 14.2 months [95% confidence interval (CI), 10.8 months-NR]. Nintedanib was well tolerated; grade ≥ 3 toxicities were uncommon and included grade 3 hypertension (15%) and liver enzyme elevation (4%). FGFR2 alterations were identified in 18% of patients but were not predictive of clinical outcome on nintedanib therapy. Alterations in cell-cycle pathway genes were associated with worse median PFS (1.61 months for patients with cell-cycle pathway alterations vs. 2.66 months for patients without, P = 0.019). CONCLUSIONS: Nintedanib treatment resulted in modest disease stabilization in patients with metastatic esophagogastric cancer. Alterations in cell-cycle pathway genes and increased global copy-number alteration (CNA) burden warrant further study as prognostic or predictive biomarkers.

Phase II Study of Temozolomide and Thalidomide in Patients with Unresectable or Metastatic Leiomyosarcoma.

We assessed the efficacy of combined temozolomide and thalidomide in patients with unresectable or metastatic leiomyosarcoma in a phase II single-institution trial. Twenty-four patients were enrolled. Temozolomide (150 mg/m(2)/day for 7 days every other week) was administered with concomitant thalidomide (200 mg/day), and continued until unacceptable toxicity or disease progression. There were no complete responses and two (10%) partial responses. Five patients (24%) had stable disease for at least six months. Fourteen patients (67%) progressed after a median of two-month treatment. The median overall survival (twenty-two assessable patients) was 9.5 months [95% CI 7-28 months]. There were no treatment-related deaths or CTC grade 4 toxicities. Thirteen patients were dose-reduced or discontinued thalidomide due to toxicity. In conclusion, this combination of temozolomide and thalidomide provided disease stabilization in a subset of patients with advanced leiomyosarcoma. We hypothesize that temozolomide is the active agent in this regimen, and should be further studied.

New strategies for treating GIST when imatinib fails.

Gastrointestinal stromal tumors (GISTs) are soft tissue sarcomas arising in the GI tract. Most GISTs have an activating mutation in KIT or PDGFR-alpha and respond to treatment with imatinib mesylate (Gleevec, Novartis), a small molecule tyrosine kinase inhibitor that blocks downstream signaling of the mutated kinase. Imatinib has dramatically improved survival in patients with unresectable or metastatic GIST; however, approximately 15 percent of patients do not respond to imatinib, and many others progress after an initial period of response or disease stabilization. New agents that target multiple kinases in GIST as well as downstream effector molecules are being developed and tested in clinical trials.