#ORPH Open Orphan – Imutex Vaccine Phase I Study Results

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 20^th and 21^st 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.

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