CHICAGO (May 18, 2015) — Although various drugs have improved outcomes for metastatic colon cancer patients, researchers continually strive to find new agents to improve treatment. Antibody-drug conjugates are a promising option, due to the fact that they can deliver chemotherapy directly into a targeted cell and destroy tumor cells while keeping healthy ones intact. One antibody-drug conjugate in particular, IMMU-130, was found to be effective in controlling drug-resistant metastatic colon cancer in patients previously treated with irinotecan-containing chemotherapy regimens, according to the results of a recent phase I/II clinical trial.
“This is a new treatment approach using an antibody-drug conjugate to deliver the treatment directly into the cancer cell and limit toxicity to healthy tissue,” said Efrat Dotan, MD, medical oncologist at Fox Chase Cancer Center. Dr. Dotan will share these results during an oral presentation at the 2015 American Society of Clinical Oncology Annual Meeting in Chicago.
The primary study objective was to determine the maximum tolerated dose among patients with metastatic colon cancer who had been previously treated with at least one prior chemotherapy regimen containing irinotecan, an already-approved agent for colon cancer treatment. Between February 2013 and November 2014, 87 patients were enrolled into the phase I/II clinical trial. Patients were treated with escalating doses of the drug on a once or twice weekly schedule. Treatment was given for two consecutive weeks on a three weeks cycle.
The drug was reasonably well tolerated, with dose-limiting toxicity of neutropenia—an abnormally low count of neutrophils, a type of white blood cell that helps fight off infection— in 10% of the patients. Stabilization of disease and tumor shrinkage were seen among this heavily pretreated patient group, according to the study results.
The researchers concluded that repeated cycles of IMMU-130 had an acceptable toxicity profile, and the results warrant further investigation of the drug in the treatment of metastatic colon cancer. “Our experience with this agent has been exciting, with manageable adverse effects and responses even in patients with irinotecan-refractory disease. We look forward to enrolling patients in future clinical trials to test IMMU-130 in combination with other agents used to treat metastatic colon cancer,” Dr. Dotan said.