Imprime PGG in Combination with Monoclonal Antibody Therapy Achieves 64% Complete Response Rate in Chronic Lymphocytic Leukemia Patients

EAGAN, Minn. -- (BUSINESS WIRE) -- All subjects in a phase 1 study of high risk, chronic lymphocytic leukemia responded to the combination therapy of Imprime PGG^®, alemtuzumab (Campath^®) and rituximab (Rituxan^®) with 64% achieving a complete response, according to data presented this past weekend at the 54^th American Society of Hematology Annual Meeting and Exposition in Atlanta, GA.

High-risk disease can be identified in patients with early stage chronic lymphocytic leukemia (CLL) using biological prognostic markers. Research shows that early monoclonal antibody (mAb) therapy with alemtuzumab and rituximab is effective and could possibly delay first standard treatment (Cancer 2008; 113:2110-8). Furthermore, the efficacy of this therapy could be improved by enhancing mAb-mediated cellular cytotoxicity.

Researchers hypothesized that Imprime PGG^®, an immunomodulating beta 1,3/1,6 glucan from Biothera, would enhance the mAb therapy in CLL patients by increasing CR3 binding to iC3b and thus enhancing macrophage, neutrophil, and NK cell mediated cytotoxicity. The 64% complete response rate achieved with the combination therapy of Imprime PGG, alemtuzumab and rituximab compares with two previous Mayo Clinic studies in CLL subjects using alemtuzumab and rituximab alone that reported complete response rates of 37% (Zent et al., Cancer 113:2110-2118, 2008) and 27% (Zent et al., Leukemia and Lymphoma, 2012).

The researchers conclude that these data support continuation of this study in a phase 2. Clive S. Zent, MD of the Division of Hematology at The Mayo Clinic presented the clinical data at the American Society of Hematology meeting.

Click here for the official abstract.

This study was funded by the University of Iowa/Mayo Clinic Lymphoma SPORE (CA097274) and Biothera.

About Imprime PGG^®
Imprime PGG is a novel immunomodulatory drug in development as a cancer therapy. Neutrophils are the most abundant immune cell 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 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 Phase 2-3 trial in KRAS wild type colorectal cancer and multiple Phase 2 clinical trials in 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.