RESEARCH TRIANGLE PARK – Medicago, a Canadian biopharmaceutical company with manufacturing operations in Durham, is reporting positive results from a Phase 3 clinical trial of its potential COVID-19 vaccine made in plants.

Based on the results, the company said it would “imminently” seek regulatory approval from Health Canada, that nation’s health policy agency.

If approved, the vaccine would become the world’s first plant-based vaccine for human use. It would be manufactured in Durham, where Medicago has a 156,000-square-foot production unit that includes a fully automated greenhouse and state-of-the-art extraction and purification system.

Medicago logo

“This is an incredible moment for Medicago and for novel vaccine platforms,” said Takashi Nagao, chief executive officer and president at Medicago. “The results of our clinical trials show the power of plant-based vaccine manufacturing technology. If approved, we will be contributing to the world’s fight against the COVID-19 pandemic with the world’s first plant-based vaccine for use in humans.”

The vaccine candidate is not approved yet by any regulatory authorities.

71% efficacy overall

In a global study involving over 24,000 adult subjects in the United States and five other countries, the vaccine, in combination with GlaxoSmithKline’s pandemic adjuvant, demonstrated an overall efficacy rate against all variants of the SARS-COV-2 virus of 71% with no related serious adverse events reported.

“The combination of GSK’s established pandemic adjuvant with Medicago’s plant-based vaccine technology has significant potential to be an effective, refrigerator-stable option to help protect people against SARS-CoV-2,” said Thomas Breuer, GSK’s global COVID-19 adjuvanted vaccines lead and chief global health officer.

Breuer said the study results were particularly encouraging because they came during a time when multiple variants of the COVID-19 were circulating, including the globally dominant Delta variant. The vaccine showed 75.3% efficacy against COVID-19 of any severity for the Delta variant.

The more recent Omicron variant was not circulating during the study.

Direct comparison of the vaccine’s efficacy with currently licensed COVID-19 vaccines is impossible because those vaccines were tested when only the ancestral virus was circulating, not subsequent variants such as Alpha, Delta, Lambda and Mu, the company noted.

Full results of the Phase 3 study will be released in a peer-reviewed publication “as soon as possible,” the company said.

Using plants as bio-factories

Medicago, founded in 1999, has spent the last two decades developing technology for producing vaccines and therapeutics in Nicotiana benthamiana, a close relative of the tobacco plant. The plant is well suited for producing vaccine components because it is easily infected by many types of viruses and can take up the viruses’ genetic code.

Once a disease-causing virus has been genetically sequenced, Medicago uses its technology to synthesize the virus’s code within the plants, causing the plants to produce virus-like particles (VLPs) in their leaves. When the VLPs are harvested, purified and formulated into a vaccine, they imitate the virus, triggering a protective response by the human immune system.

The technology can quickly produce safe vaccines and therapeutic antibodies because no live, infectious viruses are involved.

Company expanding

Medicago is headquartered in Quebec City, where it also has greenhouses, a pilot plant and laboratories. The company has over 500 employees, including 200 in Durham, where it established operations in 2010 through a partnership with the U.S. Defense Advanced Research Projects Agency (DARPA).

Medicago is building a new complex in Quebec that will encompass nearly 1 million square feet of space for its headquarters, laboratories and production operations. The facility will be capable of producing up to 1 billion doses of pandemic vaccines annually.

If approved, the company’s COVID-19 vaccine would be produced in Durham with fill and finish completed in Montreal for the Canadian government’s order. Vaccine for the Phase 3 trial was also produced in Durham.

Medicago is hiring for positions in Durham and expects to expand its production workforce there if the vaccine is approved, the company said. Its careers webpage lists 28 job openings in the United States and Canada, with 18 of them based in Durham.

In addition to its COVID-19 vaccine candidate, the company is developing vaccines for the pandemic flu, the seasonal flu, and rotavirus and norovirus infections.

Medicago is an affiliated company of Mitsubishi Tanabe Pharma Corp. of Osaka, Japan.

(C) N.C. Biotech Center