FYB207


Innovative SARS-CoV-2 blocker

Formycon is developing FYB207, an innovative antiviral drug for the treatment of COVID-19 based on a long-acting ACE2-IgG-Fc fusion molecule.

Current development status

In vitro laboratory studies
Preclinical phase
Clinical phase

Mode of action


SARS-CoV-2 and other corona viruses use ACE2 on the surface of human cells as an entry point for respiratory tract infections. The viral spike-1 protein binds to ACE2 on the surface of the target cells. After docking, the virus is taken up into the cell.

Laboratory studies showed that the addition of soluble ACE2 blocked the coronaviruses SARS-Cov-2 and SARS-CoV, preventing infection of cells. ACE2 also has a natural enzyme activity in the cardiovascular system that provides potential protection for the lungs, heart and kidney from threatening organ failure. Formycon has therefore combined the human ACE2 protein to the constant part of human antibodies (IgG4-FC) by using computer-assisted structural design, creating a highly effective SARS-CoV-2 blocker with enzymatic activity (FYB207).

In vitro tests show that FYB207 completely prevents infection of the cells, while preserving natural enzyme activity. Due to its design, the FYB207 compound provides maximum protection against virus escape by mutation compared to vaccines and neutralizing antibodies.


Possible fields of application (indications)


Formycon is initially developing FYB207 for hospitalized COVID-19 patients for which no sufficiently effective drugs currently exist. Other possible indications include newly infected COVID-19 patients without symptoms and preventive use, e.g., in caring facilities.

FYB207 can potentially be used to target all coronaviruses that use ACE2 as a port of entry and thus also serves as a precaution for future corona pandemics.

Due to the potential organ protective function through ACE2 enzyme activity, another indication for FYB207 would be Acute Respiratory Distress Syndrome (ARDS) of various etiologies.


Our development work


Different variants of the virus blocker were investigated in laboratory scale for manufacturability, stability and virus inhibition. In vitro tests with isolates of SARS-CoV-2 as well as the original SARS-CoV from 2003 show that Formycon’s ACE2 antibody fusion protein effectively binds to SARS corona viruses and completely prevents infection of the cells. A scientific publication on the detailed in vitro development results can be found here: https://doi.org/10.1101/2020.12.06.413443.

The poster presentation for the international “Keystone Symposia – Antibodies and Vaccines as Drugs for COVID-19” can be found here.


Next milestones

Completion of the preclinical in vivo development phase planned for Q2/2021. The start of the clinical trial is also planned for 2021, depending on the agreement with the relevant authorities.