Scancell makes progress with 'Covidity' trial plans

Immunotherapy developer Scancell updated the market on ‘Covidity’ clinical trial plans, and the publication of preclinical data on two vaccine candidates from the research programme.

The AIM-traded firm’s Covidity programme is a collaboration between itself and scientists in the newly-established Centre for Research on Global Virus Infections, and the new Biodiscovery Institute at the University of Nottingham, and Nottingham Trent University.

It noted that the programme had received funding from Innovate UK.

Following findings from the preclinical data, a phase 1 study on the “next-generation vaccine” would start in both South Africa and the UK in the second half of the year, subject to local regulatory approvals.

The company said that, according to the newly-published preclinical data on the two lead bivalent vaccine candidates ‘SN15’ and ‘SN17’, the “next-generation” Covid-19 vaccines could offer improved protection against new SARS-Cov-2 variants of concern, due to the inclusion of the “highly conserved” nucleocapsid N-antigen in addition to the more variable spike protein.

Based on the “potent” immune responses generated in the preclinical studies, Scancell said it was planning to test the safety and immunogenicity of the two vaccines in a phase 1 clinical trial.

The paper showed that SN15 elicited strong pro-inflammatory T-cell responses to both the N and S proteins, with those responses being “significantly enhanced” by fusing the nucleocapsid sequence to a modified Fc utilising Scancell's ‘AvidiMab’ technology.

It said the SN15 vaccine also stimulated high titre neutralising antibody (VNAbs) responses to the receptor-binding domain (RBD) of the S protein, and showed cross-reactivity with S proteins from the emerging variants Alpha and Beta.

The company said it believed the DNA platform could be easily adapted to target variant RBD and N proteins, and demonstrated that SN17, encoding the Beta RBD sequence, stimulated cross-reactive antibody mediation and T-cell immunity.

It said the research supported the translation of the DNA vaccine platform into the clinic, thus offering a “particular advantage” for targeting emerging SARS-CoV-2 variants.

“We believe that the combination of cross-reactive VNAbs with durable memory responses against the conserved N protein may confer an added advantage by eliciting potent T cells that can destroy cells infected with any of the variant viruses, providing an extra layer of protective surveillance,” said founder and chief scientific officer, Lindy Durrant.

Scancell said a regulatory application to initiate a phase 1 clinical trial of Covidity had been submitted to the South African Health Products Regulatory Authority (SAHPRA).

Part 1 of the study would be conducted at the University of Cape Town Lung Institute in Covid-19-naive, unvaccinated, healthy adult volunteers.

Such a study was not possible in the UK due to the rapid rollout of the vaccination programme.

The firm said the aim of the study would be to assess the safety and immunogenicity of the two candidates in unvaccinated individuals, and would have two cohorts assessing different doses of the two candidates using two different needle-free injection methods.

After demonstration of safety in South Africa, Scancell said it would seek approval from the Medicines and Healthcare products Regulatory Agency (MHRA) to initiate a UK extension of the study, in which the second candidate would be given to healthy volunteers who had already received two doses of an approved vaccine.

The immune responses from that part of the Covidity study would allow it to assess the ability of the candidate to boost the immune response against current and potential future strains of Covid-19 in pre-vaccinated individuals.

“There is a significant threat from future mutations of the SARS-CoV-2 virus, as we have seen with the rapid transmission of the Delta variant,” said chief executive officer Dr Cliff Holloway.

“Our next generation Covid-19 vaccine has the potential to work alongside currently approved vaccines by protecting the population against new variants of SARS-CoV-2.

“We look forward to initiating this trial in South Africa and the UK, and to updating the market in due course on further developments from the Covidity programme.”

At 1435 BST, shares in Scancell Holdings were up 4.24% at 22.15p.