Open Orphan plc announced that hVIVO, a subsidiary of Open Orphan plc, has signed a £14.7 million contract for an influenza characterisation study and a follow on influenza human challenge study with an existing top five global pharmaceutical client. Revenue from the contract will be recognised across 2022 and 2023. This follows a challenge virus manufacturing contract signed with the same client, announced on 4 May 2022.

Following completion of the challenge agent manufacturing, the characterisation study will identify a dose of the flu challenge agent that causes a safe and reliable infection in healthy volunteers. The study, which is sponsored by hVIVO, is expected to start in third quarter 2022, subject to the relevant regulatory approvals, and will enrol volunteers recruited from the Company's clinical trial volunteer recruitment arm, FluCamp. As part of the study, hVIVO Labs will develop and validate challenge agent specific assays for the new flu challenge agent to US Food and Drug Administration (FDA), European Medicines Agency (EMA) and International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) standards. This includes quantitative polymerase chain reaction (qPCR) for viral load determination, viral infectivity assay and serological assays for antibody level determination.

Following completion of the characterisation study, hVIVO will conduct a human challenge study, expected to commence in first quarter 2023. The study will enable the Company to determine the efficacy of a number of different vaccine candidates for the reduction in incidence of symptomatic flu infection and disease severity in healthy volunteers. This will help select which of the candidates to progress further into later stage clinical trials.

The vaccine study can be initiated, subject to receipt of the relevant regulatory approvals, as soon as the Company completes the infectivity and safety data review from the characterisation study and establishes the best challenge agent dose for safe volunteer inoculation.