A phase II study of FOLFOX combined with nab-paclitaxel in the treatment of metastatic or advanced unresectable gastric, gastroesophageal junction adenocarcinoma: a Big Ten Cancer Research Consortium trial

Background: Doublet platinum or taxane-based therapies are the current standard backbone of treatment for advanced gastric/gastroesophageal junction (GEJ) adenocarcinoma. Previously used anthracycline-based triplet regimens are no longer used routinely due to toxicity and lack of superior efficacy. We hypothesized that the addition of nab-paclitaxel to FOLFOX (FOLFOX-A) would induce higher efficacy and better tolerability. Patients and Methods: Eligible patients with chemotherapy-naïve advanced unresectable HER2-negative gastric or GEJ adenocarcinoma were enrolled in this phase II single-arm trial of FOLFOX (oxaliplatin 85 mg/m², leucovorin 400 mg/m², 5-FU 2400 mg/m² over 46-48 hours) + nab-paclitaxel (150 mg/m²) every 14 days of a 28-day cycle. Evaluable disease according to RECIST v1.1 for solid tumors was required. The primary endpoint was the objective response rate. Simon’s optimal 2-stage design was used to test 5% versus 20% response rate with 90% power and 10% one-sided type I error rate. Results: The study enrolled 39 patients. Median age was 63 (range 20-80) years, 30 (77%) were male, 34 (94%) were White, and 21 (57%) had gastric tumors. The median number of cycles completed was 4.5 (range: 0-36), and 25 patients required dose reductions or discontinuation of at least one component due to toxicity. Of the 38 patients evaluable for response, 15 (42.9%) had complete/partial response (CR/PR) as the best response, and 13 (37.1%) had stable disease. progression-free survival (PFS) and OS data were available for 38 patients, with a median follow-up duration of 27 months (range: 18.2-51.9 months for censored patients). Median PFS was 6.6 months (95% CI: 5.6-12.9), with 31.0% (95% CI: 18.4%-52.4%) 12-month PFS rate. The median OS was 10.5 months (95% CI: 8.8-20.7), 12-month OS rate was 44.7% (95% CI: 31.4%-63.7%). Treatment-related grade 3-4 toxicities included peripheral sensory neuropathy and anemia (18.4% each), neutropenia (15.8%), and diarrhea and lymphopenia (7.9% each). Conclusions: FOLFOX-A has a significant response rate, expected toxicities, and should be considered for future investigation in combination with immunotherapy given the recent approvals.