5527 Background: The rationally designed, fully synthetic epothilone ZK-EPO has demonstrated significant activity against ovarian cancer cell lines. The results of the first completed phase I study (one 30-min infusion q3w) indicated good tolerability, with peripheral neuropathy as the most common toxicity; signs of activity, including objective responses, were reported. A randomised phase II trial was performed to determine the efficacy, safety and tolerability of 2 infusion durations in patients with platinum-resistant ovarian cancer. Methods: Eligible patients were at first or second relapse, had a platinum-free interval of <6 months, and disease evaluable by RECIST or, if not measurable, by CA125 (GCIG criteria). Patients were randomised to receive 3-hour or 30-min infusions of 16 mg/m2 ZK- EPO administered 3-weekly. Simon’s two-step design was used; 13–34 patients were to be accrued per arm. An arm would be continued if at least 2/13 patients responded. The drug would be considered efficacious if ≥6/34 patients responded. Results: To date, 63 patients have entered the study (accrual completed November 2006). Data is currently available on the 30 patients in step 1. Four patients were excluded from efficacy analysis due to tumor histology (clear or mucinous), as per protocol. 24 patients were taxane pre-treated. 4/13 patients responded in the 3-hour arm so accrual continued; in the 30-min arm 1/13 responded. A total of 101 infusions were administered to patients in step 1. The most common drug-related toxicity >grade 1 in the 3-hour and 30-min arm was grade 2–3 peripheral sensory neuropathy (3-hour: 9/15 patients, 30 min: 5/15 patients). Two patients withdrew because of neuropathy, both in the 3-hour arm. Other drug-related toxicities >grade 1 occurring in >1 patient were fatigue (n=3), arthralgia (n=3), nausea (n=3) and lethargy (n=2). Conclusion: Preliminary results indicate that ZK-EPO, administered as a 3-hour infusion at a dose of 16 mg/m2, has promising activity against platinum-resistant ovarian cancer. Updated response data on all patients will be presented. Peripheral neuropathy currently appears to be the only noteworthy toxicity of ZK-EPO. [Table: see text]
837P Phase II trial of oncolytic vaccinia virus primed immunochemotherapy in platinum-resistant/refractory ovarian cancer (PRROC) (NCT02759588)