Inovio Pharmaceuticals has reported positive interim results from the initial two cohorts in Phase I clinical trial of its Covid-19 vaccine candidate, INO-4800.

With funding from the Coalition for Epidemic Preparedness Innovations (CEPI), the Phase I trial initially recruited 40 healthy adults aged 18 to 50 years at two sites in the US. Participants were given two 1mg or 2mg doses of INO-4800 four weeks apart.

An analysis by independent Data Safety Monitoring Board showed that the Inovio Covid-19 vaccine candidate was generally safe and well-tolerated in all participants across both cohorts through week 8.

The company added that all ten reported adverse events (AEs) were grade 1 in severity, without any serious adverse events (SAEs).

Immunology assays, including tests for humoral and cellular immune responses, are being performed for both INO-4800 dose cohorts following two doses at week 6.

So far, preliminary data on humoral and T cell immune responses has revealed that 94% of total participants experienced overall immunological response rates.

Apart from the positive interim Phase I results, the company announced that INO-4800 was able to protect mice in SARS-CoV-2 viral challenge studies, where the vaccine candidate prevented viral replication in the lungs of animals.

Furthermore, INO-4800 has been chosen to be part of a non-human primate (NHP) challenge study under the US Government’s Operation Warp Speed programme.

Inovio Pharmaceuticals president and CEO Dr Joseph Kim said: “We are very encouraged by the positive interim safety and preliminary cellular and humoral immune response results to date as well as the inclusion of INO-4800 in Operation Warp Speed.

“We are also pleased that INO-4800 vaccination abrogated viral replication in the lungs of mice challenged with SARS-CoV-2.”

The company has expanded the Phase I trial to include older participants in additional cohorts. It also intends to launch a Phase II/III efficacy trial in the coming months.