Increasing available choices for conjugate vaccine technology by producing carrier proteins in Scarab Genomics? reduced genome E. coli strains

Period of Performance: 12/15/2016 - 05/31/2017


Phase 2 SBIR

Recipient Firm

Scarab Genomics, LLC
Madison, WI 53713
Principal Investigator
Principal Investigator


Scarab Genomics? goal is to commercialize carrier proteins for conjugate vaccine manufacture. This proposal focuses on two bacterial carrier proteins that have been approved by the FDA and that are in use in pre-clinical and clinical studies: Exoprotein A (EPA) from Pseudomonas aeruginosa and Protein D (PD) from non-typeable Haemophilus influenzae. These proteins are difficult to make by the conventional E. coli fermentation processes and are in very short and unreliable supply commercially (EPA), or presently unavailable (PD). Scarab?s Clean Genome E. coli fermentation technology has not only enabled continuous flow fermentation for at least 30 days to become reality, but has proved to be very efficient at producing the carriers we have tested, with reliable production and good yields. Scarab strains provide much greater safety and productivity than conventional bacterial fermentation strains. Conjugate vaccines have been enormously successful in preventing pneumococcal and meningococcal diseases, both in the developed and the developing world. Pfizer?s pneumococcal vaccine Prevnar 13 made USD 4 billion last year. There is still a huge unmet demand for pneumococcal vaccines in many parts of the world, estimated by the vaccine alliance Gavi as two billion doses over the next decade. Although the carrier protein CRM197 is used in many pneumococcal vaccines, problems such as carrier-induced epitope suppression (CIES) contributed to the decision by GlaxoSmithKline to use PD as a carrier for 8 of the 10 pneumococcal serotypes targeted in Synflorix ($550 million in sales in 2012). Interest in conjugate vaccine research is expanding to other infectious diseases (such as HIV and malaria) and also chronic conditions and addictions. The need for multiple carrier proteins is driven by (i) CIES, a reduction in immunogenicity of vaccines that use the same carrier protein (particularly relevant as the desire to combine vaccines and improve coverage increases); (ii) the need to explore multiple carrier proteins when developing conjugate vaccines against specific antigens; (iii) the emergence of rare serotypes that require new vaccination with a different carriers. This field of study is clearly relevant to the NIH mission both for research and the commercial availability of carriers for preclinical and clinical studies, as well as the production of approved vaccines. The Phase I specific aims of this Fast-Track proposal will demonstrate that EPA and PD express well in Scarab?s Clean Genome strains and that they can be produced in a continuous flow process. This will establish feasibility of commercialization. New Scarab technologies will be tested that (i) avoid use of antibiotics in the fermentation process and (ii) enable cleaner and more efficient recovery of the product. In Phase II, for each carrier, the fermentation system will be fully optimized and a downstream process devised, including purification procedure, thorough analysis of the product and preparation for sale as research grade reagents.