AIMM Therapeutics' Pre-fusion RSV Antibodies Facilitate Improved Approach to Vaccine Development

Data Showing Potent Immune Stimulating Response Published in Science

AMSTERDAM -- AIMM Therapeutics B.V., a leading developer of a new generation of therapeutic antibodies, announced today that researchers have used the Company's unique family of antibodies that neutralize respiratory syncytial virus (RSV) to engineer an improved vaccine against RSV. In a paper published in Science titled 'Structure-Based Design of a Fusion Glycoprotein Vaccine for Respiratory Syncytial Virus'¹, a team of scientists from the Vaccine Research Center (VRC) at the U.S. National Institute of Allergy and Infectious Diseases describe how structural biology insight into how AIMM's highly potent RSV antibodies work enabled them to engineer a vaccine immunogen able to trigger a response 40 times higher than needed to neutralize RSV infection.

"Respiratory syncytial virus remains a large unmet medical need. Over 160,000 children per year die worldwide from RSV infections and the subsequent clinical complications. Although most adults have acquired immunity, very young children, immune compromised adults, and the elderly all have a significant risk of complications arising from RSV infections," noted Hergen Spits, AIMM's Chief Scientific Officer. "AIMM's technology platforms allow rapid identification of unique and strongly neutralizing antibodies in blood samples donated by healthy adults as was the case here. These antibodies are not only useful in vaccine development, as this current paper shows, but are being developed as therapeutics, which will have utility in cases where vaccines are not effective.

On the surface of RSV, there is a protein simply known as F that facilitates fusion with human cells during the infection process. Earlier this year Science published an article titled 'Structure of RSV fusion glycoprotein trimer bound to a prefusion-specific neutralizing antibody' describing the unique ability of AIMM's highly neutralizing antibodies to recognize a prefusion complex of the RSV-F protein. The research showed that by targeting the RSV-F protein while it was in the compact prefusion conformation, AIMM's antibodies could halt the critical unfolding of this protein into the conformation required for viral entry into cells. Working with this insight, researchers were able to identify the critical structure that the RSV-F protein presents to the antibody. Immunizing mice with a stabilized form of this structure produced an extremely efficient immune response to the protein that resulted in protection against subsequent challenge with RSV.

"This has been an excellent collaboration with Dr. Kwong and his colleagues at the NIH," said Jan de Vries, Chief Executive Officer at AIMM. "I think that this research clearly demonstrates how the novel antibody technology platforms developed by AIMM can be used to inform future vaccine development, not only in RSV but in several other serious infectious diseases."

About AIMM Therapeutics

AIMM Therapeutics (AIMM) is a leading antibody company that based on its synergistic, state-of-the-art antibody technology platform develops high affinity human monoclonal antibodies from immortalized and selected B cells of individuals who produce antibodies with high therapeutic value. AIMM antibodies can be further affinity matured in a proprietary process that does not require molecular engineering. AIMM has a broad product pipeline targeted at pathogenic viruses and bacteria, and is expanding its pipeline with drug candidates for cancer and inflammatory diseases. For more information: www.aimmtherapeutics.com.

¹ Jason S. McLellan et al, Science 342, 592 (2013)