The objective of this project is to continue developing an adenoviral serotype 5 (Ad5) vector vaccine against Ad5[E1-, E2b]-Her2/neu that is effective in stimulating cell-mediated immunity (CMI) in animals previously immune to Ad5. The Ad5[E1-, E2b-]- Her2/neu vaccine endpoint is to treat patients with HER2 over expressing cancers. HER2 is a protein that has been reported to be useful as a vaccine treatment target. Evidence indicates that a broad CMI response is needed to treat certain HER2 expressing. Ad5 vector vaccines induce CMI responses and have emerged as a leading candidate to be used as a treatment vaccine as a treatment vaccine delivery platform. Current Generation Ad5 vaccines have proven less effective than anticipated and adverse reaction are in question. Furthermore, pre-existing Ad5 immunity of most humans causes decreased effectiveness. To address these issues, we have developed an advanced ad5 based vector that is devoid of early genes E1, E2b3, and E3. These """"""""E2b-deleted"""""""" vectors, with deletions in the polymerase and preterminal protein genes, have an expanded cloning capacity greatly reduced expression of viral late genes as compared to current generation. The reduced expression of multiple Ad5 viral genes has been demonstrated to be advantageous for vaccine development for reasons such as reduced antigenic competition, greater longevity of advantages are important in the presence of pre-existing Ad5 immunity, and provide the E2b deleted vectors stealth-like attributes. The Company has exclusive license for the new Ad5 vector system and the E.C7 cell line that supports vector production. The proposed studies are designed to construct and test the effectiveness of HER2/neu vaccines based on the new E2b-deleted Ad5 platform, which will carry the HER2/neu gene. The Ad5 vaccine will be tested for its potential to induce HER2/neu memory CMI responses as a prime and for their re-immunization (boost) potential in Ad5- na?ve and Ad5-immune mice. Mice will be monitored for any adverse easy effects of the vaccine. This project will result in an effective, safe, easy to produce, stable, and easy to use HER/2 neu therapeutic vaccine. Our goal is to initiate a Phase 1 clinical trial using the Ad5 vector Platform within a year of funding.
During this study, we will further develop an advanced vector delivery system for an Ad5[HER2/neu treatment vaccine. The vaccine platform is needed to break through the barrier presented by vaccines that have had prior adenovirus infections which include most humans.
| Gabitzsch, E S; Xu, Y; Balcaitis, S et al. (2011) An Ad5[E1-, E2b-]-HER2/neu vector induces immune responses and inhibits HER2/neu expressing tumor progression in Ad5 immune mice. Cancer Gene Ther 18:326-35 |
