PRO-PLATINUM: A randomized, double-blind, placebo controlled study to investigate the efficacy of a probiotic intervention on the gut and vaginal microbiome of ovarian cancer patients undergoing treatment with platinum chemotherapy

BACKGROUND: PRO-PLATINUM evaluates whether a 5-strain probiotic formulation can favorably modulate the gut microbiome during platinum-based chemotherapy in ovarian cancer (OC), while assessing feasibility, safety, and translational correlates of response and toxicity. PATIENTS AND METHODS: PRO-PLATINUM is an IRB-approved, randomized, double-blind, placebo-controlled trial enrolling 124 patients with stage II-IV or platinum-sensitive recurrent high-grade OC receiving platinum-based chemotherapy. The study opened to enrollment in February 2026. Participants are randomized 1:1 to a 5-strain probiotic (WBF-038) or placebo, stratified by newly diagnosed advanced versus recurrent disease. The intervention contains inulin and five microbial strains: Akkermansia muciniphila, Anaerobutyricum hallii, Clostridium beijerinckii, Clostridium butyricum, and Bifidobacterium infantis, and is administered orally twice daily beginning within seven days of cycle 1 and continuing through seven days after the completion of cycle 6. Eligible patients must have ECOG performance status 0-2, adequate organ function, and no major probiotic-related contraindications. Stool, blood, and vaginal samples are collected at baseline, cycle 3, and cycle 6; tumor tissue is collected at surgery when available. The primary endpoint is change in gut microbiome composition by whole-genome metagenomic sequencing. Secondary endpoints include intervention adherence, biospecimen feasibility, recurrence-free survival, and overall survival. Exploratory endpoints include toxicity, postoperative infections, stool consistency, diet, medication and antibiotic exposure, quality of life, symptom burden, serum metabolomic and immune profiling, vaginal and tumor microbiome composition, and associations between microbial features and clinical outcomes. CONCLUSIONS: PRO-PLATINUM will evaluate treatment feasibility and safety and generate prospective translational data to inform future microbiome-directed strategies to improve treatment tolerance, quality of life, and outcomes in OC patients.