Abstract 5780
Background
Anti-PD-1 blocking monoclonal antibodies (mAbs) such as nivolumab or pembrolizumab have shown potent anti-tumor effects in different metastatic cancers. Similarly, anti-HER-2 mAbs such as Herceptin and Perjeta are approved for breast cancer. These mAbs are only effective in 10-25% of cancer patients, and are limited by high costs, side effects and development of resistance. Contrary to treatment with monoclonal antibodies, chimeric B-cell cancer vaccines incorporating a “promiscuous” T cell epitope have the advantage of safer and cheaper alternatives, producing a specific immune response that induces memory B & T cell responses, while reducing immune evasion, suppression and resistance.
Methods
We have translated two HER-2 combination peptide vaccines (B-Vaxx) to the clinic in a Phase 1/2b trial to safely deliver curative and transformative cancer immunotherapies to advanced cancer patients. We have created and established the development of a novel B-cell peptide vaccine (Key-Vaxx) with high immunogenicity that binds to human PD-1 and produces tumor inhibition in vivo in two animal models of colon cancer. We will describe the CT-26, CT26-HER2 and MC38 tumor models in Balb/c and C57/Bl6 used to test for synergistic effects of anti-PD1 immunization therapy in combination with anti-HER2 immunization therapy. The immunogenicity/optimal immunologic dose and toxicity profile was investigated in beagle dogs.
Results
We show robust HER-2 and PD-1 antibody responses in mice, beagle dogs and non-human primates. The individual (PD-1) or combined vaccination (B-Vaxx)) was effective in reducing tumor growth in a Balb/c and C57Bl/6 syngeneic model of colon carcinoma and exhibited superior activity compared to the positive gold control anti-mouse PD-1 (CD279) monoclonal antibody.
Conclusions
Development of PD-1 B-cell vaccine was successful, showing no evidence of toxicity or autoimmunity in mice, rabbits and beagle dogs. The combination vaccines could provide improved outcomes in early stage disease sparing patients the toxicity of chemotherapy. A phase 1 clinical trial with the PD-1 vaccine is under planning.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
NIH; Imugene.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
3664 - Longitudinal changes in cell-free DNA (cfDNA) methylation levels identify early non-responders to treatment in advanced solid tumors
Presenter: Andrew Davis
Session: Poster Display session 3
Resources:
Abstract
3212 - Multigene panel testing results for hereditary breast cancer in 1325 individuals: implications for gene selection and considerations for guidelines.
Presenter: Georgios Tsaousis
Session: Poster Display session 3
Resources:
Abstract
2591 - PIK3R5 genetic predictors of hypertension induced by VEGF-pathway inhibitors
Presenter: Julia Quintanilha
Session: Poster Display session 3
Resources:
Abstract
4377 - ERBB2 mRNA as a predictor in HER2-positive (HER2+)/hormone receptor-positive (HR+) metastatic breast cancer (BC) treated with HER2 blockade in combination with endocrine therapy (ET): a retrospective analysis of the ALTERNATIVE and SOLTI-PAMELA trials.
Presenter: Nuria Chic
Session: Poster Display session 3
Resources:
Abstract
3439 - Early on-treatment vs pre-treatment tumor transcriptomes as predictors of response to neoadjuvant therapy for HER2-positive inflammatory breast cancer
Presenter: Sonia Pernas
Session: Poster Display session 3
Resources:
Abstract
2512 - AXL expression predicts poor prognosis and lack of efficacy of anti-angiogenic and anti-epidermal growth factor receptor (EGFR) agents in patients (pts) with RAS wild type (WT) metastatic colorectal cancer (mCRC)
Presenter: Claudia Cardone
Session: Poster Display session 3
Resources:
Abstract
4061 - Prevalence of EGFR mutations and its correlation with Egyptian patients’ human kinetics (PEEK Study)
Presenter: Adel Ibrahim
Session: Poster Display session 3
Resources:
Abstract
2547 - Evaluation of tumor microenvironment identifies immune correlates of response to combination immunotherapy with margetuximab (M) and pembrolizumab (P) in HER2+ gastroesophageal adenocarcinoma (GEA)
Presenter: Sergio Rutella
Session: Poster Display session 3
Resources:
Abstract
4671 - Clinicopathological and molecular criteria assessment for the screening of hypermutated proficient mismatch repair (pMMR) colorectal cancers (CRC) with exonucleasic domain POLE (edPOLE) mutations (mt).
Presenter: Benoit Rousseau
Session: Poster Display session 3
Resources:
Abstract
3862 - Tumor mutation burden and microsatellite instability in colorectal cancer
Presenter: Francesca Fenizia
Session: Poster Display session 3
Resources:
Abstract