Results from the Phase III placebo-controlled efficacy study of Medicago’s plant-based Covid-19 vaccine candidate in combination with GlaxoSmithKline’s pandemic adjuvant have shown positive results.
Vaccine efficacy was demonstrated in an environment dominated by SARS-CoV-2 variants, unlike most published Phase III efficacy trials for currently licensed Covid-19 vaccines that were conducted when only the ancestral virus was circulating, making direct comparisons impossible.
The trial included 24,000 adults across six countries. The overall vaccine efficacy rate against all variants of SARS-COV-2 was found to be 71%. The vaccine candidate demonstrated efficacy of 75.3% against Covid-19 of any severity for the Delta variant and 88.6% against the Gamma variant. The trial did not include the new Omicron variant.
During the study, no related serious adverse events were reported and reactogenicity was generally mild to moderate and transient; symptoms lasting on average only one to three days. To date, the Phase III results have confirmed the safety profile is consistent with Phase II results. The frequency of mild fever was low (<10%), even after the second dose. Full results of the Phase III study will be released in a peer-reviewed publication as soon as possible.
Based on these results, Medicago will imminently seek regulatory approval from Health Canada as part of its rolling submission. The vaccine candidate is not yet approved by any regulatory authority.
“This is an incredible moment for Medicago and for novel vaccine platforms. 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,” said Takashi Nagao, CEO and President at Medicago. “I want to thank everyone who participated in our clinical trials, our collaborators at clinical trial sites, our partners at GSK, the Government of Canada and Government of Quebec, all of our employees and Mitsubishi Tanabe Pharma Corporation, for their commitment to advancing vaccine science when the world needs it.”
Thomas Breuer, GSK’s global Covid-19 adjuvanted vaccines lead and Chief Global Health Officer, said: “These are encouraging results given data were obtained in an environment with no ancestral virus circulating. The global Covid-19 pandemic is continuing to show new facets with the current dominance of the Delta variant, upcoming Omicron, and other variants likely to follow. 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.”
Medicago has been developing its plant-based technology for the past 20 years, using unique technology to produce Virus-Like Particles (VLP) for its protein vaccines. VLPs are designed to mimic the native structure of viruses, allowing them to be easily recognised by the immune system. Because the VLPs lack core genetic material, they are non-infectious and unable to replicate. VLP vaccines developed by other technologies have traditionally been used worldwide for more than 30 years.
“I am pleased to see our vaccine candidate moving forward and bringing to the world the first plant-based vaccine against Covid-19, diversifying the pool of vaccines available to help improve public health and protect more people,” said Yosuke Kimura, Chief Scientific Officer at Medicago.