New Covid-19 mRNA Vaccine Trial Begins

(Sam Moqadam, Unsplash)

12 Mar. 2021. A clinical trial is underway testing a new Covid-19 vaccine based on messenger RNA, developed by biotech company Translate Bio and drug maker Sanofi. The companies expect the new vaccine, code-named MRT5500, to provide a starting point for addressing emerging variants in the SARS-CoV-2 virus responsible for Covid-19 infections.

Like the BioNTech/Pfizer and Moderna vaccines already authorized, MRT5500 delivers synthetic messenger RNA, or mRNA, targeting the surface protein on the SARS-CoV-2 viral spike, contained in lipid or natural oil nanoscale particles. Preclinical research with lab mice and monkeys show two doses of MRT5500 invokes an immune response, both as neutralizing antibodies and as T-cells.

The new early- and mid-stage clinical trial is enrolling 415 healthy adults at 13 sites. Participants are randomly assigned to receive two doses of MRT-5500 at one of three dosage levels — 15, 45, or 135 micrograms — three weeks apart. The study team is tracking the safety and tolerability of MRT-5500, as well as its ability to invoke an immune response. The trial is not yet listed in either the U.S. or European Union clinical trial registries.

Sanofi and Translate Bio say they’re working on improving the temperature stability of MRT5500, first to a storage temperature of -20 degrees C, then to routine refrigerator temperatures of 2 to 8 C. The companies are also continuing preclinical studies of MRT5500 against emerging variants from mutations in the SARS-CoV-2 virus.

Collaboration began in 2018

“With the impact of mRNA vaccines demonstrated during the pandemic,” says Translate Bio CEO Ronald Renaud in a statement, “our joint development team remains steadfast in our commitment to advancing MRT5500 as part of the collaborative effort to overcome this global health crisis.”

Translate Bio in Lexington, Massachusetts develops therapies based on mRNA, nucleic acids derived from the genetic codes in DNA, and used by cells to produce the amino acids in proteins for cellular functions. Its technology designs mRNA as therapies to correct missing or malfunctioning proteins, which the company says restores functioning gene expression without entering the cell nucleus or changing a recipient’s genome. Translate Bio says its treatments harness the cells’ own mechanisms to produce working proteins, thus making these therapies able to address targets previously considered undruggable.

As reported by Science & Enterprise in June 2018, Translate Bio and Sanofi Pasteur in Paris, Sanofi’s vaccines division, began a partnership to develop vaccines against infectious diseases, a licensing deal that could bring Translate Bio as much as $850 million. The new Covid-19 vaccine is part of that collaboration, making Translate Bio eligible for a $25 million milestone payment from Sanofi.

Sanofi Pasteur is also developing a Covid-19 vaccine with drug maker GlaxoSmithKline. A mid-stage clinical trial of that reformulated vaccine is now underway in the U.S. and Central America.

More from Science & Enterprise:

• CEPI Funding SARS-CoV-2 Variant Vaccines
• Biotech, UK Govt to Design Covid-19 Variant Vaccines
• One-Dose Covid-19 Vaccine Shown to Prevent Hospitalization
• Covid-19 Vaccine Shown Safe, Effective in Russian Test
• Covid-19 Vaccine Shown Active Against Variants

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