Preventive COVID-19 Peptide Vaccine Aims to Provide Broad and Long-Lasting Immune Response

Scientists have developed and successfully tested in silico a preventive COVID-19 peptide vaccine which is designed to elicit long-term T cell immunity in contrast to most of the vaccine candidates being developed with antibodies.

The preventive vaccine product, PolyPEPI-SCoV-2, has been developed by Treos Bio Limited (London, UK) using its proprietary, computational vaccine design technology. The company has transferred all rights, including pending patent applications, for the preventive COVID-19 peptide vaccine to a newly-formed subsidiary, PepTC Vaccines Limited (London, UK).

PepTC Vaccines’ PolyPEPI-SCoV-2 investigative vaccine consists of 10 different, 30-amino acid long synthetic peptides. To design its experimental SARS-CoV-2 vaccine, Treos took into consideration both the data obtained from patients who recovered from the previous coronavirus (SARS-CoV) epidemy in 2003 and other information specific to variants of the current coronavirus. Treos selected peptide fragments of the conserved regions of the presently known multiple viral structural protein sequences as well as multiple shared personal epitopes (PEPIs) of subjects with different ethnicities for its model population. Epitope selection was directed toward both HLA class I and HLA class II specific PEPIs to induce robust T cell responses that will establish memory T cell pools.

In silico preclinical testing of the PolyPEPI-SCoV-2 vaccine in diverse ethnic groups of approximately 16,000 HLA genotyped subjects from a US bone marrow donor database, resulted in an equally high proportion of subjects showing both CD8+ and CD4+ T cell responses in each ethnic group. PepTC Vaccines expects to advance to human clinical studies for its investigational PolyPEPI-SCoV-2 vaccine by October 2020 and announce preliminary trial results in March 2021. PepTC Vaccines’ approach provides cost-effective and immediately scalable manufacturing since it relies on well-established, accessible manufacturing technology and widely available chemicals to produce the synthetic peptides used in Treos’ immunotherapies.

“Our efforts are focused on the development of an effective, safe, and potentially best-in-class vaccine against SARS-CoV-2. We are addressing the challenges of the heterogeneity of individuals’ immune response, the potential for structural variations in the infecting virus, and the observed phenomenon of long-term immunity to coronaviruses likely stemming from T cell activity,” said Dr. Christopher C. Gallen, Executive Chairman of Treos. “Based on our clinical experience with our PolyPEPI peptide immunotherapy in metastatic colorectal cancer patients and our validated in silico human model, we believe that our approach has the potential to provide a broad and long-lasting immune response, independent of gender, age, or ethnicity, and be able to protect people worldwide against COVID-19.”

“We anticipate that as the coronavirus continues to evolve and as more data are collected, additional mutations will be observed. Such mutations will not affect the global coverage of our vaccine, provided that they occur outside of the identified epitope regions,” said Enikő R. Tőke, Ph.D., Chief Scientific Officer for Treos. “If mutations do occur within any of the epitope regions selected, then the intact immunogenic epitopes could still provide protection against the virus since a majority of the subjects will still have a broad repertoire of virus-specific memory T cell clones.”

Related Links:
Treos Bio Limited
PepTC Vaccines Limited