Theralase Demonstrates Proof-of-Concept for Canadian-Made COVID-19 Vaccine

Theralase Technologies Inc. has demonstrated proof-of-concept for the development of a Canadian-made SARS-CoV-2 (COVID-19) vaccine.

In August 2020, Theralase reported that it had executed a Sponsored Research Agreement (SRA) with the University of Manitoba (UM) medical microbiology department to commence research and development of a Canadian-made vaccine, utilizing Theralase’s patented and proprietary PDC, TLD-1433.

In November 2020, Theralase reported that, UM was able to demonstrate that TLD-1433 was effective in the rapid destruction of various viruses, including: H1N1 Influenza, Zika and a Biological Safety Level (BSL)-2 coronavirus at low nanomolar (nM) concentrations.

All these enveloped viruses are similar in structure to SARS-CoV-2 virus (BSL-3), which is responsible for COVID-19. These initial results strongly suggested that Theralase’s PDC technology may be used to develop an inactivated virus vaccine2 that may be effective against COVID-19 and hence warranted further preclinical evaluation.

Further research by UM also identified that the spike protein responsible for the transmission of a coronavirus into a host cell, remained intact after light-activated TLD-1433 inactivation, suggesting that the vaccine developed by this technology could potentially stimulate a protective antibody immune response in a mammalian host.

In April 2021, Theralase reported that it had executed a Collaborative Research Agreement (CRA) with the Public Health Agency of Canada’s (PHAC) National Microbiology Laboratory to further expand upon the research and development achieved at UM, by researching and developing a Canadian-based COVID-19 vaccine.

Under the terms of the agreement, Theralase and PHAC are collaborating on the research, development and optimization of a COVID-19 vaccine by inactivating the SARS-CoV-2 virus with Theralase’s light-activated PDC, TLD-1433.

Theralase is pleased to be able to report today that PHAC has demonstrated that light-activated TLD-1433, was effective in rapidly inactivating the SARS-CoV-2 virus by up to 99.99%, compared to control in an in vitro study. Further research is required to confirm these findings.

These results have now laid the groundwork for the next phase of the CRA, which is evaluating the Theralase COVID-19 vaccine in the ability to prevent animals from contracting COVID-19, when exposed to the virus.

Darwyn Kobasa, PhD, Head, High Containment Respiratory Virus Group, Special Pathogens, PHAC, said “My team’s initial results indicate that, when activated by light, TLD-1433 is very effective in inactivating the COVID-19 virus at low concentrations, thus demonstrating proof-of-concept in the development of a Canadian-made COVID-19 vaccine.”

Kevin Coombs, PhD, Professor, Department of Medical Microbiology at UM, added “The work conducted at my lab and the work conducted by PHAC’s National Microbiology Laboratory, has demonstrated that a large range of enveloped viruses can be successfully inactivated by light-activated TLD-1433 at low concentrations. I am delighted that Theralase’s and my initial preclinical research has proven to be effective in COVID-19.”

Dr. Arkady Mandel, MD, PhD, DSc, Interim Chief Executive Officer and Chief Scientific Officer, Theralase, stated “The latest preliminary results by Dr. Kobasa and Dr. Coombs, demonstrate that the Theralase vaccine may potentially be effective as a Canadian-made wholly inactivated vaccine to prevent individuals from contracting COVID-19 in the future and warrant further research to confirm the findings. The research also demonstrates that the Theralase platform is extremely versatile, with an ability to be applicable to a wide range of enveloped viruses. This would allow the company to tailor the vaccine to be potentially effective against contracting various viruses (existing and/or new) and their associated variants. Based on this encouraging data, the company intends to move forward in the research, development and commercialization of the Theralase COVID-19 vaccine, subject to the required regulatory approval.”

TLD-1433 is a patented PDC with over 10 years of published peer reviewed preclinical research and is currently under investigation in a Phase 2 Non-Muscle Invasive Bladder Cancer (NMIBC) clinical study for Bacillus Calmette-Guérin (BCG)-Unresponsive patients at 5 Canadian Clinical Study Sites (CSS) and 7 US-based CSS.

Theralase is a clinical stage pharmaceutical company dedicated to the research and development of light activated Photo Dynamic Compounds and their associated drug formulations intended to safely and effectively destroy various cancers, bacteria and viruses. For more information, visit and