Clivatuzumab tetraxetan shows promising results in patients with metastatic pancreatic cancer

Immunomedics, Inc. (Nasdaq:IMMU), a biopharmaceutical company focused on developing monoclonal antibodies to treat cancer and other serious diseases, today announced that its proprietary antibody, clivatuzumab tetraxetan, labeled with yttrium-90 (Y-90) plus low-dose gemcitabine continues to produce promising efficacy results in patients with previously untreated, inoperable, locally advanced or metastatic pancreatic cancer.

At the 2010 American Society of Clinical Oncology annual meeting, Dr. Allyson Ocean of the New York Presbyterian Hospital, Weill Medical College of Cornell University, New York, NY, reported for the research team that among the 37 evaluable patients, the disease control rate for all dose groups combined was 57%, including 6 patients (16%) with partial responses (PR) by RECIST criteria (i.e., responses showing decreases in tumor size of more than 30% by CT and in the absence of new lesions) and 16 patients (41%) with stable disease (SD). Most promising efficacy was observed in the group of 16 patients that received 12 mCi/m² of Y-90 weekly for 3 weeks, with a 69% disease control rate (19% PR and 50% SD). In addition, anecdotal reports indicated patients have good performance and decreased pain medication after treatment.

"These updated results continue to show evidence of tumor shrinkage and stabilization in about 60% of evaluable patients, but most importantly without the usual toxicities accompanying aggressive chemotherapy regimens," commented Dr. Ocean.

At the time of reporting, 15 patients (41%) have achieved survival longer than 6 months. This includes 4 patients (11%) at lower doses who received 1-3 additional cycles with survival for more than 1 year. Progression-free survival and overall survival data need more follow-up, particularly for more recent patients entered at higher Y-90 dose levels.

"We are pleased that this ongoing Phase Ib/II study is experiencing rapid patient enrollment and that results continue to be encouraging in this dismal disease," remarked Cynthia L. Sullivan, President and CEO of Immunomedics.

Of the 37 evaluable patients, 25 received one cycle, while 13 patients were retreated, with 11 receiving 2 cycles and 1 patient each receiving 3 or 4 cycles.

The study also showed that responses increased with higher doses of Y-90 since there were 19% PR in patients given 12 mCi/m² weekly for 3 weeks compared with 8% at the 9 mCi/m² dose level. In spite of higher cumulative Y-90 doses, treatment was well tolerated with few non-hematologic side effects. Hematologic suppression was manageable without major infections or bleeding events, and reversible in most patients, even after 4 treatment cycles.