ObjectiveTo determine the maximum tolerated dose (MTD) of paclitaxel combined with a fixed dose of cisplatin (75 mg/m2) delivered via hyperthermic intraperitoneal chemotherapy (HIPEC) to patients with ovarian cancer. MethodsThis multicenter Phase I trial employed a Bayesian Optimal Interval (BOIN) design. The MTD was determined to have a target dose-limiting toxicity (DLT) rate of 25%. The starting dose was 175 mg/m2. The Data and Safety Monitoring Board made decisions regarding dose escalation or de-escalation in increments of 25 mg/m2 for subsequent patient cohorts, up to a maximum sample size of 30 or 12 patients treated at a given dose. ResultsTwenty-one patients participated in this study. Among the three evaluable patients who received 150 mg/m2 paclitaxel, no DLTs were observed. Among the 12 evaluable patients who received 175 mg/m2 paclitaxel, two reported DLTs: one had grade 4 neutropenia and one had grade 4 anemia, neutropenia, and leukopenia. Four of the six evaluable patients who received 200 mg/m2 paclitaxel reported DLTs: one patient had grade 4 diarrhea, one had grade 3 kidney injury, and two had grade 4 anemia. The isotonic estimate of the DLT rate in the 175 mg/m2 dose group was 0.17 (95% confidence interval, 0.02–0.42), and this dose was selected as the MTD. ConclusionPaclitaxel, when combined with a fixed dose of cisplatin (75 mg/m2), can be safely administered intraperitoneally at a dose of 175 mg/m2 in patients with ovarian cancer who received HIPEC (43 °C, 90 min) following cytoreductive surgery.