By Cameron Johnston
CHICAGO, IL -- June 4, 2007 -- Women with advanced ovarian cancers who are treated with an intraperitoneal regimen (IP) of carboplatin and paclitaxel fare better than patients in a previous study who were treated with IP cisplatin/paclitaxel.
Both regimens also appear to have favourable results compared with the conventional intravenous administration of the drugs.
In a poster discussion here on June 3rd at the 43rd American Society of Clinical Oncology Annual Meeting (ASCO), Carolyn N. Krasner, MD, medical oncologist, Massachusetts General Hospital, Boston, Massachusetts, United States, said the pharmacokinetics of the study showed positive results, with relatively few toxicities.
Administration of chemotherapy by the IP route has been done in the past but it is a labour-intensive procedure, Dr. Krasner said. Her study was designed to evaluate the pharmacokinetics, efficacy, and toxicity of the dual-agent regimen. Past studies have shown that IP dosing results in a lower maximum concentration and a significantly higher area under the curve (AUC) compared with IV administration.
Another aim of the study was to determine whether systemic uptake of the drugs changed over time, since there has been some suggestion that IP administration would cause the peritoneum to sclerose, which would then impair systemic absorption of future treatments.
In the study, 40 women with advanced ovarian cancer (36 with stage III disease, all had been optimally debulked) received their first dose of carboplatin/paclitaxel as an IV infusion. The next 5 administrations were intraperitoneal. Carboplatin was delivered at AUC6 on day 1, and paclitaxel was given at a dose of 60 mg/m2 on days 1, 8, and 15. Patients who completed all 6 cycles underwent a second-look operation (SLO).
Twenty-six women were able to complete all 6 cycles, which is better than what was seen in the prior study with cisplatin/paclitaxel, Dr. Krasner said.
Toxicity was mild, he said, with grade 3 or 4 toxicity consisting of neutropenia in 10 patients (25%), vomiting in 2 patients (5%), fatigue in 2 patients (5%), and fatigue and anaemia in 2 patients (5%). There was no grade 3 or 4 peripheral neuropathy or alopecia.
Twenty-four women underwent SLOs. A complete pathological response was seen in 17 (72%) patients, which Dr. Krasner said was an extremely good finding. This compares with 57% who showed a complete pathological response in the earlier cisplatin/paclitaxel trial.
Five women were determined to be microscopically positive when the SLO was done.
Dr. Krasner said problems with the port insertion, mainly infections, are still an issue that needs to be worked out, but the rate of port problems did not increase for women who were having weekly delivery of the paclitaxel as compared with those who had less frequent administrations.
Overall, Dr. Krasner commented, the pharmacokinetic results of this study were encouraging and the tolerability and efficacy results suggest the study should be replicated in a larger population of women.
[Presentation title: Results of All-Intraperitoneal Carboplatin and Paclitaxel Regimen Shows Good Tolerability and Efficacy for Advanced Ovarian Cancer. Abstract 5521]
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