Background: Sabarubicin (MEN-10755) is a third generation anthracycline, with a remarkable antitumor activity in human tumor xenografts, including doxorubicin-resistant tumors. Phase I studies have shown that myelosuppression is the main toxicity of sabarubicin, while its cumulative cardiotoxicity is mild.
Methods: The aim of the study was to evaluate the activity and safety profile of sabarubicin in patients with locally advanced or metastatic ovarian cancer failing 1st line platinum and/or taxane based chemotherapy, and relapsing earlier than 6 months after the last chemotherapy. Eligible patients received sabarubicin at the dose of 80 mg/m2 (dose level 0) every 3 weeks over 30 minutes. Dose was to be escalated to 90 mg/m2 (dose level +1) after the 1st cycle in case of grade 0-1 toxicity, while it was to be reduced to 60 mg/m2 (dose level -1) in case of toxicity. Response was assessed every 2 courses according to WHO criteria. Toxicity was graded according to Common Toxicity Criteria version 2.0. Gehan's design was used for sample size determination.
Results: Nineteen patients were enrolled and received 65 courses. One patient had a confirmed partial response, 9 patients had stable disease, 5 patients had disease progression, 3 patients were not evaluable for response, while one patient had an early progressive disease. The duration of response was 88 days. Mean time to disease progression was 125 days (range 56-188). Median survival was 62 days (range 36-202). Hematologic toxicity was moderate, since grade 3-4 neutropenia was observed in 25 out of 52 courses at 80 mg/m2, and grade 4 neutropenia occurred in one out of 12 courses at 90 mg/m2. Other grade 3-4 toxicities were: fatigue (five cases), nausea (two cases), stomatitis, general health deterioration, anorexia, vomiting, abdominal pain, hyponatremia (one case each). Cardiac toxicity was observed in the study; in fact, left ventricular ejection fraction (LVEF) fell below 50% in 2 patients, and 3 patients had a >15% decrease of LVEF from baseline, but there were no signs/symptoms of congestive heart failure.
Conclusions: Sabarubicin showed limited activity in patients with resistant ovarian cancer. However, the observed data on disease stabilization, together with the drug's overall manageable toxicity profile, may prompt to its further investigation in advanced ovarian cancer.