Skip to Content

Excelimmune Presents Preclinical Data at ICAAC Demonstrating that Human Recombinant Polyclonal Antibody Therapy Provides Protection Against MRSA

--Mixing up Antibody Cocktails for Protection Against MRSA--

WOBURN, Mass.--(BUSINESS WIRE)--Sep 13, 2010 - Excelimmune, Inc. announced positive results from preclinical studies evaluating the efficacy of its human recombinant polyclonal antibody (HRPA) therapy against infections caused by methicillin-resistant Staphylococcus aureus (MRSA). The results were presented in a poster session at the 50th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC). The study demonstrated full immune protection against an otherwise 100% lethal dose of MRSA, and this result was achieved at an antibody concentration far lower than that typically required for monoclonal antibodies. MRSA is currently a leading cause of death due to infectious disease in the United States, surpassing deaths from HIV/AIDS-related infections and tuberculosis combined.

Excelimmune is generating a HRPA therapy against S. aureus by cloning antibodies from many different individuals who have been naturally exposed to a variety of S. aureus strains, including MRSA, from the environment. These efforts may result in a broad-spectrum therapeutic with neutralizing activity against multiple S. aureus antigens.

“The study represents an important proof-of-principle for Excelimmune's unique approach,” said Quinton Zondervan, Chief Executive Officer. “Excelimmune seeks to address a major unmet need in treating drug-resistant bacterial infections by creating a diverse mixture of cloned human antibodies that target the disease agent. We are actively optimizing the formulation of our proprietary antibody composition against a diversity of S. aureus strains, including MRSA.”

Vincent Coljee, Ph.D., Chief Scientific Officer of Excelimmune, added, “Excelimmune's HRPA technology is designed to fill the gap between monoclonal antibodies and IVIG therapeutics by harnessing the synergistic action of multiple antibodies using a production process that overcomes the inherent supply and safety limitations of blood-derived immunoglobulin products. HRPA therapeutics can be manufactured using recombinant techniques outside of the human body. Furthermore, by being fully human, HRPA therapeutics are less likely to cause side effects than artificially constructed, humanized or animal-derived antibodies.”

About the Study

In the study, a preclinical model was used to compare an antibody cocktail consisting of five unique antibodies (pentaclonal) with untreated controls against increasing doses of S. aureus. The pentaclonal cocktail binds to several different S. aureus antigens. At S. aureus doses that were 100% lethal in the control group, there was 100% survival in the group treated with the pentaclonal. In fact, the pentaclonal provided such effective protection that the amount of S. aureus required for 50% lethality was nearly doubled in the pentaclonal group as compared to the control group.

The poster, titled “Human Recombinant Antibody (Ab) Cocktails Protect against Methicillin-Resistant Staphylococcus aureus (MRSA) Infection in Mice,” was presented in a session from 11:15 AM to 1:15 PM on Monday, September 13, 2010.

About Human Recombinant Polyclonal Antibodies

Human recombinant polyclonal antibodies are mixed populations of therapeutic antibodies that bind to multiple regions (epitopes) on a specific antigen or to multiple antigens (of bacteria, viruses, and other microorganisms), in contrast to monoclonal antibodies, which only bind to one specific epitope. By binding to multiple regions, the polyclonal antibodies allow the body to fight off illness more readily. The antibodies are cloned from naturally occurring human antibodies in a laboratory and are then manufactured for human medical use.

About Excelimmune

Excelimmune, Inc. is a biopharmaceutical company specializing in the development of recombinant polyclonal antibodies to create novel therapies for treating disease in humans. Excelimmune's antibody therapies harness the diversity and effectiveness of the human body's adaptive immune system. The company is initially focusing on the treatment of infections caused by Staphylococcus aureus, including the drug resistant superbug, MRSA. This next generation technology is also believed to be applicable in the treatment of other pathogenic bacteria and viruses, disease causing proteins, and cancer. Excelimmune, founded in 2006, is a private company located in Woburn, MA.


Contact: Excelimmune:
Quinton Zondervan, 617-497-4303 x10
MacDougall Biomedical Communications
Kari Watson, 781-235-3060


Posted: September 2010