Phase 3 Trial of Adjuvanted COVID-19 Vaccine Candidate Commences Enrollment in the US, Canada

As part of an ongoing phase 2/3 study, phase 3 clinical testing of a plant-derived COVID-19 vaccine candidate (Medicago) in combination with a pandemic adjuvant (GSK) commenced following approval to proceed with participant enrollment from regulatory authorities in both Canada and the United States.

The regulatory authorities’ decision was based on positive interim phase 2 data from the ongoing phase 2/3 study, which led to the approval of the phase 3 trial being conducted among a population of healthy adults. Additionally, another study addressing the feasibility of a vaccine candidate to address emerging COVID-19 variants was started by Medicago in order to investigate the ability to additionally support this area of need as well.

“We are pleased to take the significant step of initiating the phase 3 clinical trial at sites around the world,” said Takashi Nagao, CEO and president, Medicago, in a press release. “This brings us one step closer to delivering an important new COVID-19 vaccine and contributing to the global fight against the pandemic along with our partner GSK.”

The vaccine candidate being investigated uses Coronavirus-Like-Particle (CoVLP) technology composed of recombinant spike glycoprotein. These glycoproteins are expressed in the body as virus-like particles, which are co-administered along with the pandemic adjuvant.

The combination of the vaccine candidate and the pandemic adjuvant were granted Fast Track designation by the FDA on February 17, 2021. This designation allows for the accelerated development and review process for the purpose of treating or preventing serious conditions that address a currently unmet medical need.

“The FDA’s decision to grant Fast Track designation for Medicago’s vaccine candidate will help us expedite our efforts to bring the first plant-derived COVID-19 vaccine to market, subject to regulatory approval,” said Carolyn Finkle, chief operating officer, Medicago, in the press release. “We are grateful to the FDA and look forward to continuing to work with them as we move forward in our clinical trials, planned application for Emergency Use Authorization, and eventual vaccine licensure application process.”

The phase 3 trial is evaluating the efficacy and safety of the adjuvanted CoVLP combination in an event-driven, randomized, observer-blinded, placebo-controlled, 2-way cross-over study design. The investigators plan to enroll up to 30,000 participants, who will be given two 3.75 microgram doses of the adjuvanted CoVLP combination administered 21 days apart.

The investigators will initially enroll healthy adults aged 18 years to 65 years during the trial, but then plan to expand the patient population to elderly adults aged 65 years and older and adults with comorbidities following positive data in the first cohort.

Upon regulatory approval, trials are planned for 10 countries, starting with Canada and the United States. During these trials, the investigators plan to enroll a diverse patient population consisting of males and females of ethnically and racially diverse backgrounds.

“This advance to late-stage clinical testing further reinforces our confidence in the adjuvanted vaccine candidate’s potential to make a difference in the continued fight against COVID-19,” said Thomas Breuer, chief medical officer, GSK Vaccines, in the press release. “We look forward to sharing results later this year.”

REFERENCE

Medicago and GSK Start Phase 3 Trial of Adjuvanted COVID-19 Vaccine Candidate. Quebec City, CA: Medicago; March 16, 2021. https://www.businesswire.com/news/home/20210316005332/en. Accessed March 19, 2021.