Open Orphan plc

("Open Orphan" or the "Company")

Positive in vitro results for FLU-v published in Vaccines

Open Orphan plc (AIM: ORPH), (to be renamed hVIVO plc (AIM: HVO) effective 26 October 2022), a rapidly growing specialist contract research organisation (CRO) and world leader in testing infectious and respiratory disease products using human challenge clinical trials, announces that positive data from a peer-reviewed study evaluating the in vitro efficacy of FLU-v, Imutex Limited's ("Imutex") broad spectrum influenza vaccine, has been published in the scientific journal Vaccines.¹

Previous clinical studies have demonstrated that FLU-v induced increased antibody and cellular responses in vivo. This placebo-controlled study evaluated the ability of FLU-v to induce cellular effector functions and cross-reactivity (both measures of the immune response, with cross-reactivity being particularly important for protection against multiple viral strains) of immune cells extracted from participants, following exposure to five different influenza strains.

The study found that measurements of IFN-γ and granzyme B production in stimulated immune cells from participants that had been previously vaccinated with either FLU-v or placebo, were significantly higher in the FLU-v group both when stimulated with vaccine antigen and also with antigens from a panel of seasonal and pandemic inactivated influenza A and B strains. These results further support the continued development of FLU-v as a broad-spectrum influenza vaccine.

FLU-v is owned by Imutex, a joint venture between hVIVO and PepTcell Limited (the legal name of SEEK Group), to develop vaccines against influenza and mosquito borne diseases such as Zika virus, malaria and other flaviviruses.

Seasonal influenza causes significant morbidity and mortality each year and a pandemic influenza continues to pose a worldwide threat. Influenza is a serious global health threat with an estimated 1 billion cases per year, 3-5 million severe cases and 290,000 - 650,000 deaths per year.

Dr Andrew Catchpole, Chief Scientific Officer of hVIVO, said: "It is encouraging to see further positive data for FLU-v, supporting its continued development as a broad-spectrum influenza vaccine. There is a large unmet need for a broad-spectrum vaccine to help battle emerging seasonal and pandemic influenza A and B viruses. Although FLU-v had already produced successful Phase II clinical data, this in vitro study is particularly important as it showed the ability of the candidate to induce an immune response against a diverse variety of influenza A and B strains."

^1. Oftung, F.; Næss, L.M.; Laake, I.; Stoloff, G.; Pleguezuelos, O. FLU-v, a Broad-Spectrum Influenza Vaccine, Induces Cross-Reactive Cellular Immune Responses in Humans Measured by Dual IFN-γ and Granzyme B ELISpot Assay. Vaccines 2022, 10, 1528. https://doi.org/10.3390/vaccines10091528  

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Notes to Editors

Open Orphan plc (London and Euronext: ORPH) is changing its name to hVIVO plc (AIM and Euronext: HVO), which is expected to take effect on the AIM market of the London Stock Exchange and the Euronext Growth Exchange market on 26 October 2022.

hVIVO is a rapidly growing contract research company that is a world leader in testing infectious and respiratory disease products using human challenge clinical trials. The Company provides services to Big Pharma, biotech, and government/public health organisations.

The Company has a leading portfolio of human challenge study models for infectious and respiratory diseases and is developing a number of new models, such as malaria and COVID-19, to address the dramatic growth of the global infectious disease market. The Paris and Breda offices have over 25 years of experience providing drug development services such as biometry, data management, statistics CMC, PK and medical writing to third party clients as well as supporting the London-based challenge studies.

hVIVO runs challenge studies in London from its Whitechapel quarantine clinic, its state-of-the-art QMB clinic with its highly specialised on-site virology and immunology laboratory, and its newly opened clinic in Plumbers Row. To recruit volunteers / patients for its studies, the Company leverages its unique clinical trial recruitment capacity via its FluCamp volunteer screening facilities in London and Manchester. The newly opened facilities have expanded the scope of the business to enable the offering of Phase I and Phase II vaccine field trials, PK studies, bridging studies, and patient trials as part of large international multi-centre studies.