Immunomedics reports results from three IMMU-130 phase I trials
Immunomedics reported the results from 3 Phase I trials with IMMU-130, the company's investigational anti-CEACAM5 antibody conjugated to the irinotecan-metabolite, SN-38. The antibody-drug conjugate was therapeutically active in all 3 trials, but a more frequent dosing schedule, with administrations of IMMU-130 once or twice-weekly for 2 weeks followed by a week off, was more active in patients with metastatic colorectal cancer than when administered every other week. Results from these Phase I studies were presented at the 2014 Annual Meeting of the American Association for Cancer Research in San Diego, CA, by a group of clinical investigators. In all three trials, measurement of SN-38 concentrations in the serum found much higher levels that were sustained longer than is typically found with irinotecan therapy, the parental drug of SN-38. However, most of the SN-38 remains bound to the antibody, keeping it in an inactive form to normal tissues while in circulation, which reduces toxicity, yet allowing for higher concentrations of activated SN-38 to be delivered to the tumor where it is released from the pH- sensitive linker. Neutropenia and manageable diarrhea were the main side effects. "These results suggest that IMMU-130 may have a high therapeutic index and can be administered in repeated cycles in advanced mCRC patients," commented CEO Cynthia Sullivan.