Translational and Preclinical Studies of a Personalized Pancreas Cancer Vaccine
The development of pancreatic cancer vaccines is an area of intense investigation and considerable yet unfulfilled promise. The current paradigm is the development of pancreatic cancer vaccines targeting shared tumor antigens. Project 4 proposed a conceptually innovative new paradigm: development of personalized pancreatic cancer vaccines targeting neoantigens.
Project 4: Synthetic long peptide vaccines for mLama4 and mAlg8 protect against tumor growth. A) Groups of mice were prophylactically injected with synthetic long peptide vaccines (SLP) (plus the adjuvant poly I:C) on days -10, -3 & +4 and challenged on day 0 with 106 d42m1-T3 sarcoma cells s.c. A SLP from HPV was used as a negative control. B) Groups of mice were challenged on day 0 with 106 d42m1-T3 sarcoma cells s.c. and therapeutically injected with SLP vaccines (plus poly I:C) on days +3, +9, & +15 post-tumor injection. Poly I:C alone or a SLP from HPV was used as a negative control. *p<0.05 **p<0.01.Investigators for project 4 have studied the dynamic relationship between the immune system and cancer in detail, ultimately proposing the cancer immunoediting hypothesis. Recently, we have focused on identifying the antigens recognized by the immune system during cancer immunoediting, and in response to cancer immunotherapies such as checkpoint blockade. These studies demonstrate that neoantigens are important tumor rejection antigens, providing strong support for our neoantigen vaccine strategy.
We have developed, optimized and validated next-generation sequencing and epitope prediction algorithms to identify and prioritize neoantigens, and will use these algorithms in the proposed clinical trial. Our initial clinical experience targeting neoantigens in patients with melanoma confirms that neoantigen vaccines are capable of generating neoantigen-specific T cell responses. We will test the safety and immunogenicity of personalized DNA vaccines targeting pancreatic cancer neoantigens in a phase 1 clinical trial. In parallel studies, we will test the ability of immune modulators to enhance vaccine efficacy in preclinical models of minimal residual disease.
Project 4 has the following aims:
- Aim 1: A phase 1 clinical trial of a personalized pancreatic cancer DNA vaccine strategy in patients who have completed adjuvant therapy for pancreatic cancer
- Aim 2: Test the ability of personalized pancreatic cancer DNA vaccines targeting CD8α+ dendritic cells to enhance antitumor immunity in a preclinical model of minimal residual disease
- Aim 3: Test the ability of CCR2 inhibitors to enhance the response to personalized pancreatic cancer vaccines in a preclinical model of minimal residual disease
These studies will provide the rationale for phase 2 clinical trials of next generation personalized vaccines, and/or combination therapies.