Immunomedics reports encouraging preliminary results from myeloma study

Approximately 21 adult patients with multiple myeloma have been enrolled in this multicenter, open-label single-arm Phase I/II study receiving milatuzumab intravenously twice weekly for four weeks. At study entry, all patients were stage II or III, based on the Durie-Salmon diagnostic criteria, which classifies stage III as the most advanced stage of multiple myeloma.

Most patients had at least four prior treatments that included bortezomib, lenalidomide and thalidomide. Approximately 16 patients completed all eight infusions; five patients prematurely discontinued treatment. After adjusting premedications and slowing infusions, the treatment has been well tolerated. Patients were evaluated over 12 weeks post-treatment, with responding patients continuing in long-term follow-up.

At the time of reporting, three dose levels have been tested: 1.5, 4 and 8mg/kg. There have been no objective responses, but four patients had stable disease for at least three months after therapy. The study is ongoing with the next cohort of patients to receive 16mg/kg.

According to the company, milatuzumab is a humanized anti-CD74 antibody which has shown efficacy in preclinical B-lymphoma models, particularly multiple myeloma. CD74 plays a role in antigen processing and is highly expressed in multiple myeloma and other B-cell lymphomas.

Cynthia Sullivan, president and CEO of Immunomedics, said: “We are encouraged by these early results and are eager to learn the effects of milatuzumab at higher doses. At the same time, we are excited to begin planning for the clinical studies of our milatuzumab-doxorubicin conjugate to take advantage of the rapid internalization property of CD74.”