Candidates: Vaccine and antibody candidates


Types: Virus-Like Particle (VLP) vaccine combining Medicago’s recombinant Coronavirus Virus-Like Particles (CoVLPs) with GSK’s pandemic adjuvant system. The companies will manufacture the COVID-19 vaccine antigen through Medicago’s plant-based production platform, which uses the leaves of a plant as bioreactors to produce the S-spike protein which self-assemble into VLPs for use in the CoVLP vaccine candidate. Two doses of 3.75μg of CoVLP are administered 21 days apart.

Medicago separately is also developing antibodies against SARS-CoV-2 through its plant-based technology platform in collaboration with Laval University’s Infectious Disease Research Centre headed by Gary Kobinger, PhD, whose lab developed a successful Ebola vaccine. That research is being funded in part by the Canadian Institutes for Health Research.

2021 Status: Medicago and GSK on May 18 reported positive Day 42 interim Phase II safety and immunogenicity data from a Phase II/III trial (NCT04636697). The study assessed Medicago’s plant-derived COVID-19 vaccine candidate SARS-CoV-2 spike glycoprotein CoVLP in combination with GSK’s pandemic adjuvant AS03 in adults aged 18-64 and older adults aged 65+, as measured by neutralizing antibody (NAb) and cell mediated immunity (IFN-γ and IL-4 ELISpot) responses, according to a preprint posted May 17 in bioRxiv.

CoVLP with AS03 induced a greater humoral response in Adults than Older Adults after a single dose but this effect was overcome with a second dose when both age cohorts responded with NAb titers that were ~10-fold higher than those in a panel of sera from patients recovering from COVID-19.

Medicago and GSK said March 16 they had launched Phase III clinical testing of Medicago’s plant-derived COVID-19 vaccine candidate in combination with GSK’s pandemic adjuvant, as part of an ongoing Phase II/III study. Medicago has received approval from U.S. and Canadian regulatos to proceed with enrolment of healthy adults in the up-to-30,000-participant Phase III portion of the trial based on what the companies said were positive interim Phase II results. GSK and Medicago added that the Phase II portion is nearing completion, with results expected to be made public in April.

On February 17, the vaccine candidate plus pandemic adjuvant received Fast Track designation by the FDA.

2020 Status: GlaxoSmithKline joined Medicago on July 7 to announce a collaboration to develop Medicago’s CoVLP vaccine. The companies plan to start Phase I clinical testing in mid-July, and assess the safety and immunogenicity of three different dose levels of antigen combined with GSK’s pandemic adjuvant and in parallel with an adjuvant from another unnamed company, administered on a one- and two-dose vaccination schedule, given 21 days apart.

The companies said they aim to complete development and make the vaccine available in the first half of 2021, with approximately 100 million doses expected to be manufactured by the end of 2021. By the end of 2023, a large-scale facility under construction in Quebec City, Canada, that is expected to deliver up to 1 billion doses annually.

GSK and Medicago also agreed to evaluate expanding their collaboration to develop a post-pandemic vaccine COVID-19 candidate, “should the need arise based on the further development of COVID-19 after the pandemic,” and other infectious diseases.

Medicago and GSK noted that CoVLPs mimic the structure of the virus responsible for COVID-19 disease, allowing them to be recognized by the immune system—while reasoning that adding an adjuvant may boost immune response and reduce the amount of antigen required per dose, allowing more vaccine doses to be produced and therefore contributing to protect more people.

The Government of Canada announced March 23 that Medicago was among companies set to receive an unspecified amount of funding from the $192 million available for new, large-scale projects under the new Strategic Innovation Fund COVID-19 funding stream—part of the government’s $1 billion COVID-19 Response Fund. Two days earlier, the Government of Quebec awarded C$7 million (about $5 million) toward the company’s vaccine development effort.

Medicago said March 12 it successfully produced a coronavirus VLP 20 days after obtaining the SARS-CoV-2 gene—the first step in developing a vaccine for COVID-19. The vaccine will undergo preclinical testing for safety and efficacy, followed by human trials anticipated to start by summer (July/August) 2020.

COVID-19: 300 Candidates and Counting

To navigate through the >300 potential therapeutic and vaccine options for COVID-19, GEN has grouped the candidates into four broad categories based on their developmental and (where applicable) clinical progress:

FRONT RUNNER – the most promising therapeutics/vaccines based on clinical progress, favorable data or both.

DEFINITELY MAYBE – earlier phases with promising partners, or more advanced candidates in development that have generated uneven data

KEEPING AN EYE ON… – interesting technology, attracting notable partners, or both, but preliminary data.

TOO SOON TO TELL – longshots pending additional experimental and/or clinical data.

GEN has also tagged the most common treatment types:


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