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Disease Mechanisms

Case study confirms effect of ACE2 drug candidate against COVID-19

An international team of researchers with the participation of IMBA - Institute for Molecular Biotechnology of the Austrian Academy of Sciences – shows, by means of a case study in the renowned specialist magazine The Lancet Respiratory Medicine, how the drug candidate APN01 (human recombinant soluble ACE2) acts specifically against SARS-CoV-2.

A promising candidate in the fight against the global SARS-CoV-2 pandemic is the human recombinant enzyme ACE2, which is currently being tested in a clinical study on patients suffering from COVID-19. A recent case study has now confirmed the efficacy of the drug candidate from Vienna with new data and shows that SARS-CoV-2, for which ACE2 is the entry point, is specifically blocked by the administration of APN01.

The basis behind the mechanism of action was already discovered at IMBA as early as 2005. ACE2 was then described by Josef Penninger and colleagues as the essential in vivo entry point of a Coronavirus that caused a global outbreak of the lung disease SARS in 2003. In the face of the current pandemic, the researchers were able to build on the findings of that time quickly, as it was shown that the new SARS-CoV-2 virus uses the same mechanism to infect cells. The typical "spikes", structures of proteins on the surface of the virus, very specifically dock to the ACE2 receptors on the cell surface. At the same time, ACE2 has a second important function as a regulator of the Renin Angiotensin System (RAS), through which ACE2 reduces blood pressure and protects organs such as the heart, blood vessels or lungs from severe disease progression. ACE2 docking sites are not only found in the lungs, but also in the heart, blood vessels, intestines and kidneys, which may explain severe disease progression of COVID-19 through organ failure and sepsis.

"ACE2 is at the center of research and drug development of COVID-19, and now we present first data on soluble ACE2 therapy in a patient with SARS-CoV-2 infection," commented Alexander Zoufaly, M.D., Senior Physician in the Department of Infectious Diseases/Clinic in Favoriten, Kaiser Franz Josef Hospital, and first author of the publication. "The results of this patient case study are very encouraging and support the rationale to further explore APN01 as a treatment for COVID-19 in Phase II clinical trials".

The current case study describes the first treatment with APN01 in a COVID-19 patient with severe disease progression. The published data show a rapid loss of viral load, a reduction in inflammatory responses and the development of high titers of neutralizing antibodies against SARS-CoV-2, associated with a significant clinical improvement in the treated patient. A few months ago, Penninger's team was able to show that the viral load could be slowed down in blood vessel organoids (human organ models from stem cells).

Peter Llewellyn-Davies, CEO of APEIRON Biologics AG, the company that developed and manufactured APN01, added: "We are pleased that our drug candidate APN01 may have helped this patient to overcome a life-threatening disease and are confident that we will be able to confirm these positive results in our ongoing and progressing pivotal Phase II clinical trial. The further scientific validation by this renowned journal reinforces our efforts to provide an effective therapy against COVID-19 for the benefit of patients and society".

"The new patient data supports APN01's ability to close the door on the virus. But unlike virtually all other drug candidates, APN01 has a dual action: it blocks the virus and can protect the lungs, blood vessels or heart from injury through its enzyme function. The current results provide essential data that this important enzyme function of APN01 is maintained in treated COVID-19 patients," says Josef Penninger, IMBA founding director and co-inventor of APN01.


Original Publication:

"Human recombinant soluble ACE2 in severe COVID-19: a case report", Zoufaly et al., The Lancet Respiratory Medicine, 20202


About IMBA
IMBA - Institute of Molecular Biotechnology - is one of the leading biomedical research institutes in Europe focusing on cutting-edge stem cell technologies, functional genomics, and RNA biology. IMBA is located at the Vienna BioCenter, the vibrant cluster of universities, research institutes and biotech companies in Austria. IMBA is a subsidiary of the Austrian Academy of Sciences, the leading national sponsor of non-university academic research. The stem cell and organoid research at IMBA is being funded by the Austrian Federal Ministry of Science and the City of Vienna.