ORPH.L Regulatory News (ORPH)

19 November 2021

Open Orphan plc

("Open Orphan" or the "Company")

Imutex to present positive Phase I clinical study results for AGS-v PLUS mosquito vaccine candidate

AGS-v PLUS mosquito vaccine candidate shows favourable safety, tolerability, and immunogenicity results

Results to be presented at the American Society of Tropical Medicine and Hygiene Annual Meeting

Open Orphan plc (AIM: ORPH) announces that data from the first-in-human Phase I clinical study evaluating the safety, immunogenicity, and in vitro efficacy of AGS-v PLUS, Imutex Limited's ("Imutex') mosquito saliva vaccine candidate against arboviral diseases, as well as data on the candidate's effect on the reproductive capacity of mosquitoes that fed on vaccinated subjects will be presented on the 20th and 21st of November 2021. Imutex Limited ("Imutex") is a joint venture with PepTcell Limited ("PepTcell") (the legal name of SEEK Group) in which Open Orphan has a 49% shareholding.

The results will be presented in two virtual sessions at the American Society of Tropical Medicine and Hygiene ("ASTMH") Annual Meeting, held from 17-21 November 2021. The titles and details of the two presentations are as follows:

· "Blood feeding on humans vaccinated with AGS-v PLUS, a mosquito salivary peptide vaccine, impairs the reproductive capacity of female Aedes albopictus mosquitoes" - Scientific Session 91: Mosquitoes-Vector Biology Epidemiology I, at 8.00 am (ET) on 20 November 2021. To be presented by Joshua Lacsina, M.D., Ph.D. of the Laboratory of Malaria and Vector Research at the National Institute of Allergy and Infectious Diseases.

· "Safety and immunogenicity of AGS-v PLUS, a mosquito saliva peptide vaccine against arboviral diseases" - Scientific Session 126: Clinical Tropical Medicine: Vector borne Disease, at 8.00 am (ET) on 21 November 2021. To be presented by DeAnna J. Friedman-Klabanoff, M.D. of the University of Maryland School of Medicine.

Following the presentations, Imutex expect to publish the results from the study in a scientific peer-reviewed journal.

Imutex was funded by the Department of Health and Social Care as part of the UK Vaccine Network (UKVN), a UK Aid programme to develop vaccines for diseases with epidemic potential in low and middle-income countries (LMICs) to carry out this study. 

Data from this study, which was performed at the University of Maryland School of Medicine (Baltimore, Maryland, U.S.) and is related to a collaboration between PepTCell and The National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH), demonstrated that AGS-v PLUS was well tolerated with no serious adverse events experienced, and that it generated a strong immune response in participants. AGS-v PLUS showed a more robust immune response compared to AGS-v, a first-generation vaccine candidate developed by Imutex. The study evaluating the effect of AGS-v PLUS on the reproductive capacity of mosquitoes that fed on vaccinated subjects found that a regimen of the vaccine in combination with an adjuvant resulted in fewer eggs laid and adult progeny in the species Aedes albopictus.

Imutex's AGS-v and AGS-v PLUS vaccine candidates are mosquito-borne disease vaccines with a novel proposed dual action mechanism of preventing infection in humans whilst controlling the mosquito population. AGS-v is composed of four synthetic peptides isolated from mosquito salivary glands. The AGS-v PLUS vaccine contains the same four peptides as AGS-v but adds a fifth synthetic peptide found in the saliva of many mosquitoes, increasing the potential breadth of protection.

Mosquito-borne diseases include Zika virus, West Nile virus, chikungunya virus, dengue, yellow fever, and malaria. There are around ~360 million cases of and more than 600,000 deaths from mosquito-borne diseases annually, although the true burden is likely underestimated. A vaccine efficacious against multiple mosquito-borne diseases could significantly impact public health.

Imutex is focused on developing broad-spectrum vaccines against influenza (flu) and mosquito borne diseases. To find out more about the product developments, both in influenza vaccine development (FLU-v) and in Zika vaccine development (AGS-v), please visit the Imutex website: www.imutex.com

Cathal Friel, Executive Chairman of Open Orphan, said: "The Company has been eagerly anticipating the results from Imutex's first-in-human Phase 1 clinical trial for its AGS-v PLUS mosquito vaccine candidate, and we now look forward to the data being presented at the upcoming ASTMH Annual Meeting.

"The positive data for the AGS-v PLUS mosquito vaccine candidate is encouraging; data showed AGS-v PLUS was well tolerated and generated a strong immune response in participants against mosquito-borne diseases, with an increased immune response compared to the four peptide AGS-v candidate. Imutex's AGS-v and AGS-v PLUS vaccine candidates both employ a novel proposed dual action mechanism that prevents infection in humans whilst controlling mosquito population by limiting transmission.

"There are more than 600,000 deaths worldwide per year from mosquito borne diseases, as such, if these positive Phase I results translate into clinical efficacy, the potential number of lives saved will be significant."

Dr Olga Pleguezuelos, Chief Science Officer at PepTcell, commented: "We are very excited about the study results. AGS-v PLUS was demonstrated to be safe and immunogenic, and not only impacted the pathogenicity of the Zika virus as seen in an in vitro assay, but also reduced the number of eggs and adult progeny of mosquitoes that fed on vaccinated subjects. The next step is to evaluate clinical efficacy in a controlled human challenge study or in a study in endemic areas. Many mosquito-borne diseases lack effective preventative and therapeutic treatments, so AGS-v PLUS could potentially save many lives."

The information contained within this announcement is deemed by the Company to constitute inside information as stipulated under the Market Abuse Regulations (EU) No. 596/2014 (as implemented into English law) ("MAR"). With the publication of this announcement via a Regulatory Information Service, this inside information is now considered to be in the public domain.

For further information please contact:

Notes to Editors

Open Orphan plc

Open Orphan plc (London and Euronext: ORPH) is a rapidly growing contract research company that is a world leader in testing vaccines and antivirals using human challenge clinical trials. The Company provides services to Big Pharma, biotech, and government/public health organisations.

Open Orphan runs challenge studies in London from both its 19-bedroom Whitechapel quarantine clinic and its state-of-the-art 24-bedroom QMB clinic with its highly specialised on-site virology and immunology laboratory. The Company has a leading portfolio of human challenge study models for infectious and respiratory diseases and is developing a number of new models. There has been an explosion in the growth of the infectious disease market, which is estimated to grow to in excess of $250bn by 2025. The Group is focused on refreshing its existing challenge models and develop new models, such as Malaria, to address the dramatic growth potential of the global infectious disease market.

Building upon its many years of challenge studies and virology research, the Company is developing an in-depth database of infectious disease progression data. Based on the Company's Disease in Motion® platform, this unique dataset includes clinical, immunological, virological, and digital (wearable) biomarkers. The Disease in Motion platform has many potential applications across a wide variety of end users including big technology, wearables, pharma, and biotech companies.

Open Orphan's Paris office has been providing biometry, data management and statistics to its many European pharmaceutical clients for over 20 years. For over 15 years, the Company's Netherlands office has been providing drug development consultancy and services, including CMC (chemistry, manufacturing, and controls), PK and medical writing, to a broad range of European clients. Both offices are now also fully integrated with the London office and working on challenge study contracts as well as supporting third party trial contracts.

About PepTcell Limited

PepTcell brings safe, effective, and low-cost treatments to patients, in the shortest time possible, to radically improve human health in major disease areas. Through its subsidiary ConserV Bioscience Limited, PepTcell develops vaccines to a broad range of infectious diseases. Headquartered in London, PepTcell also researches, develops, and sells over the counter and prescription medicines.

About ConserV Bioscience Limited

ConserV Bioscience Limited, based in Oxfordshire, United Kingdom, is a clinical-stage vaccine development company focused on advancing safe and effective vaccines that protect against endemic and emergent infectious diseases. Founded in 2020 as a subsidiary of PepTcell Limited, it has an experienced scientific and leadership team. It is harnessing its novel in silico proprietary platform to identify highly conserved regions of viral proteins that contain a high number of reactive T-cell epitopes with extensive HLA coverage. ConserV Bioscience has a pipeline of vaccines at various stages of pre-clinical and clinical development including vaccine candidates to protect against HIV, Hepatitis C, Hepatitis B, Rotavirus, Chagas, and broad-spectrum coronavirus. www.conservbio.com

About The National Institute of Allergy and Infectious Diseases

The National Institute of Allergy and Infectious Diseases is an institute in the National Institutes of Health, an agency of the Unites States Department of Health and Human Services. NIAID's mission is to better understand infectious, immunologic, and allergic diseases and to use this knowledge to treat and prevent such diseases. NIAID also has a mandate to respond to emerging public health threats. Toward this end, NIAID supports basic and applied research to expand knowledge in all areas of infectious, immunologic, and allergic diseases and supports research that bolsters our ability to appropriately response to emerging and re-emerging disease threats.