Profectus BioSciences has in-licensed two powerful vaccine delivery platforms that can be used either alone or in combination to improve therapeutic outcomes.  Profectus has also assembled the manufacturing capacity to make each approach a real plug & play opportunity, vastly simplifying the construction and production of clinical trial materials.  Our therapeutic vaccine program is focused on indications in the antiviral market where there are still high unmet needs, namely HCV, HPV, HSV, and HIV

pDNA Vaccines.  DNA vaccines are genetic subunit vaccines that prompt the host cells at the site of immunization to express selected protein subunits of the target pathogen.  Since their discovery, DNA vaccines are viewed as an extremely promising vaccine modality but have been plagued by poor immunogenicity in clinical trials.  To solve this problem, Profectus coformulates plasmids expressing its immunogens with those expressing potent molecular adjuvants such as IL-12 and delivers these combinations using in vivo electroporation.  The result is the delivery of DNA based vaccines that promise to alter the clinic outcome of infected patients.

Vesicular stomatitis virus (rVSV) Vectored Vaccines.  VSV is a negative-strand, non-segmented RNA virus from the order Mononegavirales that has been redesigned to enable delivery of vaccine immunogens.  The rVSV technology in-licensed by Profectus was originally developed in the laboratories of Jack Rose, Ph.D. of Yale University and further optimized and attenuated by investigators at Wyeth.  VSV is a particularly attractive candidate for this purpose because its genome can accommodate more than one foreign gene and contains its own adjuvant that activates the immune system through TLR7.  Since their replication is cytoplasmic, and their genomes are comprised of RNA, rVSV are incapable of integrating within the genomes of infected host cells – a highly desirable safety feature.  Unlike Adenovirus and other viral vector vaccines employed today, human infection with VSV is rare, so the general population is free of pre-existing, virus-neutralizing immunity that would prevent the vaccine from “taking” in the immunized person and attenuating any resulting efficacy.  Recombinant VSV vectors replicate with a high degree of efficiency and elicit potent humoral and cellular responses against the target pathogen.  Numerous papers from Jack Rose, Ph.D. and the team at Profectus demonstrate the potential of rVSV as a vaccine vector.  Profectus is exploiting this technology to develop effective therapeutic vaccines.

Transition-State Vaccines The Company is developing a novel HIV Vaccine Immunogen based on its proprietary strategy called Transition-State Vaccines. This strategy targets immune responses to conserved portions of viral spikes. This is accomplished through the use of chimeric fusions between a portion of the viral surface spike and a small binding portion of its cognate receptor via a small amino acid linker. The linker is sufficiently long that the two components will interact to complete an intermolecular bond. Such immunogens redirect the immune response away from highly variable regions of the envelope spike that usually act as immunological decoys to regions that are highly conserved. For HIV, these conserved regions could be the “Achilles heel” for all HIV isolates. These constructs are produced from a single construct, thus allowing production in a variety of mammalian cell systems.  It can also be incorporated into both DNA and vectored vaccines in order to stimulate key cellular responses such as CTLs. 

Genetic Adjuvants: To support its vaccine program, the Company has in-licensed an adjuvant technology from UMBI that can be directly encoded into the genetic vaccines, such as DNA vaccines, and can improve their performance.  Genetic vaccine platforms are favored by many vaccine companies because they provide flexibility and uniformity in vaccine construction and production as well as strong IP positions.  However, they do not always induce the desired protection to the target disease or pathogen. To solve this problem, the Company’s Genetic Adjuvant technology uses the enzymatically-active region of cholera toxin (CTA1) as well a number of cytokines including IL-12.  By doing so, this adjuvant can facilitate the induction of potent and potentially protective immune reponses to the target pathogen.