Immunomedics has reported results that indicate CD74 is expressed at high levels in the majority of gastrointestinal tumors, which may allow milatuzumab, the company’s humanized anti-CD74 antibody, to be used as a therapy for gastrointestinal cancers, either on its own or conjugated with drugs or toxins.
The objective of the company’s present study was to evaluate the level of expression of CD74 in several gastrointestinal cancers. The expression of CD74 in pancreatic cancer was high. Approximately 85% of the specimens (48 out of 56) presenting a mostly intense, diffuse labeling pattern and an additional 9% having a moderate to intense, focal pattern, the company said. Similar results were seen with colorectal carcinomas.
Of 66 colorectal carcinomas, 34 (52%) gave intense, diffuse labeling with an additional 20% having a moderate to intense focal staining pattern. For gastric cancer specimens, 57% (16 out of 28) produced the diffuse pattern and 25% the focal pattern. However, all seven gastrointestinal stromal tumors were found negative for CD74 expression, the company noted.
These data suggest that CD74 is expressed at high levels in pancreatic and colorectal cancers and, as a result, milatuzumab may be effective in treating these solid tumors, according to the company.
Cynthia Sullivan, president and CEO of Immunomedics, said: It is important for us to evaluate the level of CD74 expression in various cancers and to understand the mechanism of action of milatuzumab. We believe these studies will help us expand the range of malignancies that can be treated with this antibody.