GlaxoSmithKline (GSK) and Medicago’s plant-based COVID-19 vaccine has achieved promising phase 2 trial data, with similar antibody response seen in adults and elderly participants within the study.

The vaccine candidate combines Medicago’s recombinant coronavirus virus-like particles (CoVLP) with GSK’s pandemic adjuvant system. Medicago’s CoVLPs mimic the structure of the SARS-CoV-2 virus that causes COVID-19, which allows them to be recognised and targeted by the immune system.

The phase 2 study, published on the online preprint server MedRxiv, found that the neutralising antibody responses in vaccinated participants were about ten times higher than those seen in a panel of sera from recovering COVID-19 patients.

In addition, researchers observed similar antibody responses across different age groups, including the 18-64 year age group and 65 years and older population.

GSK and Medicago announced in March that they had started a phase 3 clinical trial evaluating two 3.75 micrograms doses of their COVID-19 vaccine, administered 21 days apart.

Currently, trial sites around the world are enrolling subjects in the US, the UK, Canada and Brazil, and further sites will begin recruiting soon.

Sanofi and GlaxoSmithKline (GSK) have announced that their delayed COVID-19 vaccine generated strong rates of neutralising antibody responses in a mid-stage trial.

The phase 2 trial enrolled 722 participants in the US and Honduras and included equivalent numbers of adults aged 18 to 59 and those aged 60 and above.

In this trial, the immune responses generated by Sanofi/GSK’s adjuvanted recombinant protein-based vaccine were in line with those measured in people who have recovered from COVID-19, the companies said in a statement.

In addition, the interim results showed 95-100% seroconversion following a second injection across all adult age groups in the trial and across all doses.

High neutralising antibody titres were also observed in participants with evidence of prior COVID-19 infection, suggesting the vaccine candidate may have the potential to be deployed as a booster vaccine.

“This positive data shows the potential of this protein-based adjuvanted vaccine candidate in the broader context of the pandemic, including the need to address variants and to provide for booster doses,” said Roger Connor, president of GSK Vaccines.

“We believe that this vaccine candidate can make a significant contribution to the ongoing fight against COVID-19 and will move to phase 3 as soon as possible to meet our goal of making it available before the end of the year,” he added.

Following these positive results, Sanofi and GSK are planning to begin a global phase 3 trial in the coming weeks.

The study will enrol more than 35,000 participants from a number of countries and will assess the efficacy of two vaccine formulations, including the D614 (Wuhan) and B.1.351 (South African) variants.

The European Medicines Agency (EMA) has issued advice for the use of GlaxoSmithKline (GSK) and Vir Biotech’s monoclonal antibody (mAb) sotrovimab for the treatment of COVID-19.

The EMA, following the completion of its review of the mAb, has concluded that sotrovimab, previously known as VIR-7831, can be used for the treatment of confirmed COVID-19 in adults and adolescents aged 12 and older who are at risk of progressing to severe disease and who do not require supplemental oxygen.

The recommendations follow a review of data, including data from a study evaluating the effects of sotrovimab in adult outpatients with mild COVID-19 symptoms.

According to a planned interim analysis of this study, sotrovimab reduced the risk of hospitalisation for more than 24 hours or death by 85% compared to placebo.

The side effects reported in the study were also found to be mild to moderate, although the EMA added that reactions related to infusions cannot be excluded and healthcare professionals are advised to monitor patients for such reactions.

The agency’s advice can be used to support national advice for European Union member states on the potential use of the mAb prior to a marketing authorisation for the treatment.
In May, the EMA announced that it had launched a rolling review of VIR-7831, based on the interim analysis of data from the phase 3 COMET-ICE trial.

A second-generation mRNA-based COVID-19 vaccine, developed as part of a collaboration between GlaxoSmithKline (GSK) and CureVac, has yielded some positive results in preclinical testing.

The vaccine candidate – CV2CoV – has been developed as part of a collaboration announced by GSK and CureVac in February.

The partnership is focusing on developing a novel mRNA-based COVID-19 vaccine by using multivalent and monovalent approaches to offer broader protection against newly emerging variants.

In an early study, the next-generation mRNA vaccine induced high levels of antigen production and strong immune responses in vaccinated animal subjects.

The data also showed that CV2CoV was able to generate significant cross-neutralisation against a number of COVID-19 variants, including the B.1.1.298 (first discovered in Denmark), the B.1.1.7 (first discovered in the UK) and B.1.351 (first discovered in South Africa) variants.

The preclinical trial tested CV2CoV in a dose range of 0.5-40µg, with fast onset of strong immune responses observed following the first dose.

Following the positive preclinical results, GSK and CureVac are expecting to launch the first-in-human clinical trials of CV2CoV in the third quarter of 2021.

CureVac’s first-generation mRNA COVID-19 vaccine is also currently in late-stage testing. Chief executive officer Franz-Werner Haas recently told CNBC that the company is planning for potential approval in the EU as early as this month.

The US has announced that it will support a proposal to waive intellectual property (IP) and patents on all COVID-19 vaccines, aiming to ‘get as many safe and effective vaccines to as many people as fast as possible’.

The Biden-Harris Administration is backing a proposal from the World Trade Organization (WTO), supported by South Africa and India, that would temporarily remove IP protections on COVID-19 vaccines.

Historically the US has been in favour of protecting IP. In a statement, US Trade Representative Katherine Toi said that although the administration “strongly believes in [IP] protections…in the service of ending this pandemic, [it] supports the waiver of those protections for COVID-19 vaccines”.

The pharmaceutical industry has opposed the proposal, with Richard Torbett of the Association of the British Pharmaceutical Industry saying the US’ move will “hinder vaccine scale-up”.

“We share the goal of getting COVID-19 vaccines to the people who need them as fast as possible, but waiving IP is not the solution. In the short term, it will hinder vaccine scale-up and in the long term, it will significantly impact global investment into new vaccines and medicines, including for future pandemics,” he added.