A vaccine against Clostridium difficile infections

Award Information
Agency: Department of Health and Human Services
Branch: N/A
Contract: 1R41AI096839-01
Agency Tracking Number: R41AI096839
Amount: $598,689.00
Phase: Phase I
Program: STTR
Awards Year: 2011
Solicitation Year: 2011
Solicitation Topic Code: NIAID
Solicitation Number: PA10-124
Small Business Information
DUNS: 832545805
HUBZone Owned: N
Woman Owned: N
Socially and Economically Disadvantaged: N
Principal Investigator
 (858) 210-3704
Business Contact
Phone: (858) 210-3704
Email: bswanson@sorrentotherapeutics.com
Research Institution
IOWA CITY, IA, 52242-
 () -
 Nonprofit college or university
DESCRIPTION (provided by applicant): In this proposal we lay out a comprehensive research plan to evaluate our vaccination strategies targeting Clostridium difficile to prevent or treat infections. With the emergence of highly antibiotic-resistant bacterial strains, new approaches for combating bacterial infections are desperately needed. In this research proposal, Sorrento Therapeutics Inc. (STI) together with researchers from the University of Iowa have outlined experiments that will harness a powerful combination of chemistry, microbiology, and immunology to provide a solid rational basis for the development and evaluation of a quorum quenching vaccine to prevent C. difficile infections. We will first evaluate passive vaccination targeting the agr quorumsensing system of C. difficile for the protection against infections caused by antibiotic-sensitive and -resistant Clostridium difficile strains. We will then establish active vaccination protocols that result in high quorum quenching antibody titers as the basis for our ultimate goal, the development of an effective C. difficile vaccine. The specific projects of our STTR research proposal are (1) Isolate neutralizing human monoclonal anti- AIP antibodies. To establish the therapeutic efficacy of passive anti-AIP immunotherapy we will isolate anti- AIP-1 and AIP-2 binders from our proprietary human monoclonal antibody phage display library, convert them to IgGs, produce and purify them, and use an assay created by our collaborator, Dr. Horswill (Universityof Iowa), to select the best candidates for testing in an in vivo hamster challenge model. (2) Demonstrate protection by selected human anti-CDAP mAbs in a C. difficile hamster infection model in vivo. STI will produce four fully human QQ CDAP antibodies for in vivo evaluation in the standard C. difficile hamster infection model, to be performed by Dr. Ellermeier (University of Iowa). (3) Demonstrate protection by an anti-AIP active vaccine in a C. difficile hamster infection model in vivo. Accomplishment of projects (1) and (2) will prove the concept that interference with quorum sensing in vivo provides protection from C. difficile infection. In this final project, the same CDAP immunogens that were used to isolate the protective mAbs from the STI human mAb phage display library will be used to actively immunize hamsters prior to C. difficile challenge. Given our preliminary data and the expertise of the investigators, we believe there is a high probability of success for this project. In a subsequent Phase II application we would test carriers and adjuvants in combinations in the C. difficile hamster infection model and a neo-natal pig model. Antibody titers will be determined prior to C. difficile challenge and the best vaccine candidate developed. The proposed product, a unique C. difficile vaccine that targets quorum sensing, would provide a much needed alternative to antibiotic management of a serious and escalating health threat. PUBLIC HEALTH RELEVANCE: Despite the approval of numerous antibiotics over the past 60 years, bacterial disease remains a serious public health problem. Many of the most harmful bacteria, including Clostridium difficile, develop resistance to approved antibiotics (so-called superbugs ) causing people with drug-resistantinfections to become seriously ill or die. Sorrento Therapeutics Inc. is working on the development of a new way to prevent and even treat bacterial disease in a manner that we believe will be much more effective than using current antibiotic therapy andthat will be unaffected by existing resistances.

* Information listed above is at the time of submission. *

Agency Micro-sites

SBA logo
Department of Agriculture logo
Department of Commerce logo
Department of Defense logo
Department of Education logo
Department of Energy logo
Department of Health and Human Services logo
Department of Homeland Security logo
Department of Transportation logo
Environmental Protection Agency logo
National Aeronautics and Space Administration logo
National Science Foundation logo
US Flag An Official Website of the United States Government