EAGAN, Minn.--(BUSINESS WIRE)-- Imprime PGG(R), an immunomodulator, is able to
enhance antitumor function of immune cells and direct a high percentage of these
cells to the tumor microenvironment, according to in vivo data presented
recently at the American Association for Cancer Research's (AACR) Third
International Conference on Frontiers in Basic Cancer Research in National
Harbor, MD. The data was presented by researchers at Biothera, in collaboration
with the University of Minnesota.
Biothera recently completed a Phase 2b clinical study in non-small cell lung
cancer (NSCLC) with Imprime PGG, cetuximab (Erbitux(R)) and two chemotherapeutic
drugs. Additionally, Imprime PGG is in a metastatic colorectal cancer Phase 3
clinical study with cetuximab and a second NSCLC Phase 2b clinical study with
bevacizumab (Avastin(R)) and two chemotherapeutic drugs. Imprime PGG is also
being studied as a possible treatment in chronic lymphocytic leukemia and
Previous in vivo tumor model research has demonstrated the synergistic effect of
Imprime PGG in combination with antitumor monoclonal antibodies against a wide
range of cancers. The new research broadens the understanding of Imprime PGG's
mechanism of action and its potential as an immunomodulator.
Immunotherapeutic-based approaches for the management of many cancer types is an
area of increasing study worldwide, according to Myra Patchen, Ph.D., chief
scientific officer at Biothera. "These observations further validate the
potential benefit of combining Imprime PGG with antitumor monoclonal antibodies
as a treatment strategy in cancer."
Imprime PGG targets different effector cell populations (neutrophils and
macrophages) than most other immunotherapies: these "innate" immune cell
populations represent approximately 60 percent of the immune cells in the body
and are normally not involved in anti-tumor activity.
"Engaging the largest population of immune cells in the fight against cancer
makes Imprime PGG an immunotherapeutic drug candidate with tremendous potential
against multiple cancer types," said Dan Conners, president, Biothera
Pharmaceutical Group. "This study enhances our understanding of the significant
benefits we are seeing in clinical trials to date."
In the study, immunodeficient mice, with or without tumors, were administered a
single dose of Imprime PGG. Three days later, immune cells in peripheral blood,
spleen, and/or tumor were isolated and evaluated for Imprime PGG binding and
In tumor-bearing mice there was a significantly higher number of neutrophils and
macrophages in the tumor microenvironment and tumor tissue of Imprime-treated
mice vs the control group and the majority of those tumor-infiltrating
leukocytes were shown to be binding Imprime PGG. Furthermore, Imprime PGG also
enhanced the antitumor function of these cells, as measured by secretion of
antitumor cytokines (TNFa, MIP- , IP-10) and cytotoxicity.
The presentation, "Immune cell priming and potentiation of anti-tumor effects by
Imprime PGG(R)," was authored by Yumi Yokoyama, Mariana. I. Nelson, Nadine C.
Ottoson, Richard Walsh, Kyle S. Michel, Michael E. Danielson and Mary A.
Antonysamy of Biothera; and Mark N. Kirstein of the University of Minnesota.
About Imprime PGG(R)
Imprime PGG is a novel immunomodulatory drug in development as a cancer therapy.
Innate immune cells are the most abundant immune cells in the body and normally
responsible for pathogen killing, but not anti-tumor activity. In preclinical
cancer models, however, Imprime PGG has been shown to bind to neutrophils and
monocytes and redirect their killing ability to reduce tumor growth and enhance
long-term survival. This targeted mechanism is synergistic with multiple
anti-tumor monoclonal antibodies, demonstrating the potential to improve patient
outcomes in a wide range of cancer indications. Imprime PGG is currently being
evaluated in a multiple clinical trials for colorectal cancer, non-small cell
lung cancer and chronic lymphocytic leukemia. For more information, view the
Biothera drug pipeline.
About Biothera, the Immune Health Company
Biothera is a U.S. biotechnology company dedicated to improving immune health.
The company is developing pharmaceuticals that engage the innate immune system
to fight cancer.
Biothera, the Immune Health Company
David Walsh, 651-256-4606 (direct)