Using GSK and Dynavax tech, Clover kick-starts COVID-19 vax trial with data drop in August

After teaming up with GlaxoSmithKline and Dynavax early on in the pandemic, Chinese biotech Clover Biopharmaceuticals has started trials of its COVID-19 vaccine and expects data in August.

The company said the first participants have been dosed in its first clinical test this week, and it's set up to assess its COVID-19 S-Trimer subunit vaccine candidate (SCB-2019). Top-line safety and immunogenicity data are slated to be ready in two months.

But it’s already looking beyond this early trial, with a phase 2b/3 vaccine efficacy test plotted by year-end.

The vaccine is based on Clover’s Trimer-Tag vaccine technology platform and comes from early deals with GSK and Dynavax.

Clover began work on a coronavirus vaccine at the start of the year when the virus appeared to be mainly contained in China, where it's based. Clover entered the race to develop a vaccine on the strength of earlier work to develop recombinant subunit-trimer vaccines for HIV and other enveloped RNA viruses.

Animal data from those programs gave Clover confidence its platform for producing covalently trimerized fusion proteins is applicable to COVID-19.

But to boost this, GSK in February lent its support to Clover’s efforts to test that hypothesis by handing over its AS03 adjuvant technology to the biotech, which incorporated the mix of squalene, DL-α-tocopherol and polysorbate into its preclinical tests.

GSK used AS03 in the Pandemrix vaccine it developed to protect people against a pandemic H1N1 strain that circulated in 2009 and 2010. Clover, like GSK before it, is looking to the adjuvant to boost the immune response triggered by its vaccine, thereby enabling it to provide protection using smaller amounts of antigen.

A month later, in March, it also tapped Dynavax for its “technical expertise” and the company’s toll-like receptor 9 agonist adjuvant, CpG 1018, to support its vaccine work.

Clover’s phase 1 will now combine its expertise alongside the tech and work out of GSK and Dynavax pacts, and is set up as a randomized, double-blind, placebo-controlled study to assess the safety, reactogenicity and immunogenicity of SCB-2019 at multiple dose levels.

The study is being conducted at Linear Clinical Research in Perth, Australia, and will enroll around 90 healthy adult participants and 60 healthy elderly participants.

Joshua Liang, CEO of Clover and co-inventor of the COVID-19 S-Trimer vaccine candidate, said: “We are pleased to achieve this significant milestone for our COVID-19 vaccine candidate, as the entire Clover team and our collaborators around the world have been working nonstop since late-January on this important program for the world. More than ever, Clover remains focused on developing a safe, effective and accessible COVID-19 vaccine at a scale that could potentially impact the course of the pandemic globally.”

Clover’s approach is different from the methodology being used by the front-runners in the COVID-19 vaccine race, namely the use of mRNA tech from Moderna, CureVac and Pfizer/BioNTech.

Though behind in the clinical race, Clover says the use of an adjuvant “is of particular importance in a pandemic situation since it can reduce the amount of antigen required per dose, allowing more vaccine doses to be produced and made available to more people.” It's also more of a known entity in vaccine development, given no mRNA vaccines have ever been approved.