"Because of the refractory nature of pancreatic cancer, single agent treatment is not expected to offer clinical benefit. Based on this Phase I experience, combined/sequential treatment with chemotherapy and fractionated radioimmunotherapy is being considered for future trials," commented Dr. Gulec.
"We have presented these preliminary results to the FDA and are in discussion with the regulatory authority for a new Phase I dose-escalation study for 90Y-hPAM4 in combination with gemcitabine using smaller Y-90 doses repeatedly," added Cynthia L. Sullivan, President and CEO of Immunomedics.
In addition, the Company presented two posters at today's meeting on the pretargeting of pancreatic cancer and B-cell lymphoma using new bispecific antibodies constructed from the Company's proprietary platform technology for protein engineering termed the dock-and-lock (DNL).
One poster was on TF10, which is a DNL construct with two binding sites for the same MUC1 antigen targeted by PAM4, and a single binding site for the histamine-succinyl-glycine (HSG) peptide. Initial therapy studies showed that pretargeting with TF10 and Y-90 labeled HSG peptide can effectively cause the complete regression of human pancreatic cancer in mice at doses well below the maximum tolerated level.
The other poster was on TF4 for the pretargeting of B-cell lymphoma. Constructed with two sites that target the CD20 antigen and one for the HSG peptide, TF4, when used in combination with radiolabeled HSG-peptide, is highly effective for imaging lymphoma implanted in mouse models either subcutaneously or intravenously. Early results indicate therapy of tumors can be achieved with 500 microCi of Y-90 or less.
hPAM4 is a humanized monoclo