Ensovibep for COVID-19

DARPin® candidates offer a differentiated approach to treating COVID-19 through a single molecule that can engage up to three parts of the SARS-CoV-2 virus simultaneously to neutralize the virus through multiple mechanisms. This offers potentially broader efficacy – across both therapeutic and prophylactic settings – and reduced potential for the development of viral drug resistance. Every DARPin® is produced through rapid, high-yield microbial fermentation for potential speed and cost advantages over mammalian cell production employed for antibodies.

Ensovibep (MP0420) is a clinical-stage candidate that is subject to an option and license agreement with Novartis AG to develop, manufacture and commercialize Molecular Partners’ infectious disease program.



COVID-19 represents the biggest disease burden in the world today through its impact on healthcare, society and economies. Almost all ongoing novel biologic therapeutic efforts aim to use receptor binding domain (RBD)-targeting antibodies for the treatment or prevention of the disease, which may lead to a global selection pressure for strains with mutations in this domain.


The DARPin® platform is designed to be used to rapidly generate diverse, multifunctional drug candidates, capable of binding to multiple targets at once. The development of tri-specific candidates with cooperative binding could allow for greater potencies and prevention of viral escape via mutations. Our anti-COVID-19 candidates are also built with a half-life enhancing DARPin® domain that binds to human serum albumin (HSA) to support long-lasting activity. HSA is found in elevated levels in the lung which may provide a further benefit in a respiratory viral setting.


Ensovibep is a unique tri-specific DARPin® candidate that has shown cooperative target binding and exhibits among the strongest virus inhibition potency reported to date. Ensovibep comprises three RBD binding domains that bind to the same epitope region on the RBD but with different antigen-binding sequences. Preclinical data supports ensovibep’s potential efficacy as both a prophylactic and as an acute therapy. It is now being evaluated in clinical studies.