Extraperitoneal Leakage as a Possible Explanation for Failure of One-Time Intraperitoneal Treatment in Ovarian Cancer

We conducted a single-arm study to determine the biodistribution of intraperitoneally (i.p.) administered ⁹⁰yttrium-labeled murine monoclonal antibody HMFG1 (⁹⁰Y-muHMFG1) in patients with advanced stage ovarian cancer. Seventeen (17) patients in complete clinical remission for epithelial ovarian cancer were included. After completion of chemotherapy, a mixture of ¹¹¹indium-labeled muHMFG1 (imaging) and ⁹⁰Y-muHMFG1 (therapy) was i.p. administered by a surgically placed, indwelling i.p. catheter. Planar and single-photon emission computed tomography images were recorded to determine the distribution of the study medication during the first 6 days postinjection. Of the first 3 patients, 2 patients had extraperitoneal leakage of up to 50% of the injected dose within 24 hours after injection of the study medication. Extraperitoneal leakage was mainly seen in the retroperitoneal spaces covering the upper and lower quadrant of the abdomen. After adjustments in the procedure, leakage was observed in 2 of the remaining 14 patients. Extraperitoneal leakage of i.p. administered therapy does occur. Such leakage would reduce the locally delivered dose of a drug and could potentially have a negative impact on therapeutic efficacy. Given the potential attraction of developing i.p. treatments for intra-abdominal cancer, the observations in this study need to be taken into consideration.