Medicago’s COVID-19 Vaccine Combined with GSK’s Vaccine Booster Triggers Immune Response in All Study Participants

Interim results of the Phase 1 clinical trial of Medicago’s (Quebec City, Canada) plant-derived vaccine for COVID-19 have demonstrated that 100% of subjects developed a promising antibody response after two doses.

The Phase 1 clinical trial was a randomized, partially blinded study of 180 healthy subjects, male and female aged 18-55, and evaluated dosages of 3.75, 7.5 or 15 micrograms of the recombinant Coronavirus Virus-Like Particle (CoVLP) vaccine candidate alone or with an adjuvant in a prime-boost regimen. Medicago tested its vaccine candidate with each of the two adjuvants - GlaxoSmithKline plc.’s (Brentford, UK) proprietary pandemic adjuvant technology and Dynavax Technologies’ (Emeryville, CA, USA) CpG 1018.


The Phase 1 immunogenicity results demonstrated that adjuvants have the potential to improve humoral and cellular immune responses compared to the non-adjuvanted formulations. All subjects in the group with GSK’s pandemic adjuvant developed anti-spike IgG antibodies after a single dose of vaccine - either 3.75, 7.5 and 15 µg. 100& of participants who received an adjuvanted formulation developed neutralizing antibody responses after Dose 2 for all dose groups. GSK’s pandemic adjuvant was dose-sparing, with the lower 3.75 µg dose of CoVLP performing comparably with the 7.5 or the 15 µg doses. Based on the Phase 1 data, Medicago plans to proceed with the Phase 2/3 clinical trial for its COVID-19 vaccine candidate, subject to regulatory approval.

“These are very promising results. After two doses, the adjuvanted vaccine candidate induced robust neutralizing antibody and cellular immune responses which is encouraging and support further clinical evaluation,” said Nathalie Landry, Executive Vice President, Scientific and Medical Affairs at Medicago. “We also observed that the antibody levels were higher after vaccination than those observed in convalescent sera from people who recovered from the disease.”

“The positive results of our Phase 1 clinical trial are a step forward in the fight against the COVID-19 pandemic and we are confidently moving forward to our Phase 2/3 trial. We’re pleased that Medicago’s innovative manufacturing technology is helping to diversify the classes of COVID-19 vaccines candidates in development. In addition to supplying up to 76 million doses to the Government of Canada, we are ready to participate globally in the fight against COVID-19,” said Dr. Bruce D. Clark, President and CEO of Medicago. “We would like to express our gratitude to the clinical trial participants who have generously dedicated their time to support the advancement of Medicago’s COVID-19 vaccine candidate. We also would like to extend our thanks to our partners GSK and Dynavax, as well as the clinical investigators.”

Related Links:
GlaxoSmithKline plc.
Medicago
Dynavax Technologies