Immunomedics has reported in an oral presentation at the 2007 Annual Meeting of the American Association for Cancer Research (AACR) that the antigen targeted by the humanized PAM4 antibody is expressed in early stage pancreatic cancer specimens, a stage before the tumor becomes invasive.
Using immunohistochemical labeling of patient tumor specimens, Dr. David. V. Gold of the Garden State Cancer Center, Belleville, NJ, in collaboration with Dr. Ralph. H. Hruban of Johns Hopkins Medical Institutions, Baltimore, MD, found that over 89% of 56 specimens of early pancreatic cancer tested positive with the PAM4 antibody. Likewise, 87% of 48 specimens of invasive adenocarcinoma of the pancreas showed positive labeling with PAM4.
According to Dr. Gold, "We found the expression of this biomarker identified by the PAM4 antibody in the earliest phase of pancreatic cancer, specifically, in 89% of 24 specimens. Importantly, the antibody did not react with normal pancreatic tissue. We believe this indicates to us that the PAM4 antibody recognizes an early biomarker for this disease, which is commonly diagnosed too late for effective therapy."
Dr. Gold is collaborating with Immunomedics to develop an early blood test to detect pancreatic cancer. Immunomedics is completing a dose-finding study evaluating the safety and tolerability, as well as initial anticancer activity, of its humanized PAM4 antibody labeled with the therapeutic isotope, yttrium-90. At the AACR conference, Dr. Gold reported on a case where the PAM4 antibody was able to localize a recurrence of pancreatic cancer in a patient who had earlier tumor resected.
Cynthia L. Sullivan, President and Chief Executive Officer of Immunomedics, remarked: "PAM4's improved sensitivity for early pancreas cancer, matched with its known high specificity for this disease based on prior work by this group, is supportive of our decision to bring it rapidly into clinical trials. Initial results from our phase I/II studies of hPAM4 in patients with pancreatic cancer will be released at the annual meeting of the Society of Nuclear Medicine in June."
About PAM4