Medicago/GSK report positive Phase III COVID-19 vaccine results

Medicago, a Canada-based subsidiary of Japan's Mitsubishi Tanabe Pharma, and UK pharma major GlaxoSmithKline (LSE: GSK) have moved a step closer to launching a plant-based vaccine against COVID-19.

The companies today announced positive efficacy and safety results from the global Phase III placebo-controlled efficacy study of Medicago’s plant-based COVID-19 vaccine candidate in combination with GSK’s pandemic adjuvant, conducted in over 24,000 subjects, adults 18 years and above, across six countries.

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 overall vaccine efficacy rate against all variants of SARS-COV-2 was 71% (95% Confidence Interval: CI 58.7, 80.0; Per Protocol Analysis: PP). The corresponding number for people with an initial seronegative status indicating no previous exposure to COVID-19 was 75.6% (95% CI: 64.2-83.7; PP).