Vaxart Announces Publication in Vaccines of Preclinical Data Supporting the Potential of its Mucosal Vaccine Technology Platform in Enabling Therapeutic Vaccination for HPV-Related Cervical Dysplasia
Vaxart, Inc. today announced the publication of preclinical data demonstrating the potential of its mucosal vaccine technology platform in enabling therapeutic vaccination against HPV-related cervical dysplasia. The data show that Vaxart’s HPV vaccine constructs can stimulate a potent immune response against the HPV16 proteins E6 and E7 that are known to transform healthy cells into malignant cells. The data, reported in the current issue of Vaccines, also shows that administration of a mucosal vaccine against these proteins in mice with HPV-expressing tumors led to reductions in tumor size and increased survival.
Persistent HPV infection plays a causative role in most cases of cervical dysplasia, which leads to cervical cancers if left untreated. While prophylactic HPV vaccines are highly effective if administered prior to infection; they have not demonstrated a therapeutic effect on established infections.
“The preclinical data published in Vaccines demonstrate that our mucosal vaccines stimulate T cells to destroy HPV-expressing cells, reducing the size of HPV-derived tumors and increasing the survival of mice bearing these tumors,” said Dr. Sean Tucker, Vaxart’s Founder and Chief Scientific Officer.
In this study published in Vaccines, the therapeutic potential of this platform was assessed in mice bearing HPV-expressing tumors. Animals were treated with vaccine candidates expressing wildtype E6 and E7 antigens from HPV16, engineered E6 and E7 that disrupt their malignant transformation potential, and fragments of E6 and E7 predicted to stimulate an immune response.
Key findings from the study include:
Ø All vaccines generated a specific T cell response to HPV16 E6 and E7 in mice.
Ø All vaccines caused significant reductions in tumor volume and increased survival compared to control groups.
Ø Concurrent administration of anti-PD-1 with vaccination further increased animal survival in small and large tumor models compared to vaccination alone.
Ø Vaccination led to significant increases in intra-tumoral T cells, including T cells that create a cytotoxic tumor environment, compared with an empty control vaccine.
Ø Vaccination led to the generation of antigen-specific cytotoxic T cells.
These results suggest that rAd5 vaccines delivered to a mucosal surface may have therapeutic potential in the treatment of HPV-derived cervical dysplasia and might be used to stimulate immune responses against other cancer-related proteins. Vaxart is continuing to evaluate its HPV vaccine candidates.
