Molecular Partners and Novartis COVID-19 Antiviral Candidate, Ensovibep, Maintains Binding and Neutralization of New Viral Variants in vitro

Zurich-Schlieren, Switzerland, February 04, 2021. Molecular Partners AG (SIX: MOLN), a clinical-stage biotech company that is developing a new class of custom-built protein drugs known as DARPin® therapeutics, and its collaborator Novartis, today announced results from a study conducted at Spiez Laboratory. The study assessed leading SARS-CoV-2 anti-infective molecules, including the collaboration’s candidates ensovibep and MP0423, against new viral variants of SARS-CoV-2, including the variants first identified in the United Kingdom (UK) and South Africa (SA). These variants are associated with faster transmissibility and an ability to evade the immunity induced by some currently available vaccines and monoclonal antibodies. The study design and results were published on the research preprint service bioRxiv here.
The study showed that ensovibep maintained very high potency and activity on all tested viral variants and mutants. MP0423 maintained activity against all tested viral variants and mutants, but demonstrated a slight loss of potency against the UK variant, while remaining in the therapeutic range. These data indicate that ensovibep and MP0423 are potentially a better approach than monoclonal antibody approaches, many of which have previously reported significant potency loss.
“At Molecular Partners, we built our antiviral candidates to deal with the issue of viral escape, through targeting multiple sites on the virus at once with a single molecule. As designed, this approach is providing broad efficacy against SARS-CoV-2, even in the presence of emerging mutations, unlike approaches that only target single viral sites,” said Patrick Amstutz, Ph.D., CEO of Molecular Partners. “These new data are highly encouraging as we look to initiate our global COVID-19 phase 2/3 registrational study in early Q2 2021 to establish our candidates’ emerging profile as potent antiviral agents with the possibility for early therapeutic intervention. Additional trials are under discussion to broaden the application space further, in other therapeutic settings. We and Novartis are committed to quickly bring our candidates to patients in need across the globe.”
In the study, based on a pseudovirion model, two new SARS-CoV-2 variants first identified in the United Kingdom (UK) (lineage B.1.1.7., del69-70, del145, N501Y, A570D, D614G, P681H, T716I, S982A, D1118H) and South Africa (SA) (early evolved variant of lineage B.1.351.; D80A, D215G, E484K, N501Y, A701V), were analyzed for infectivity in the presence of different inhibitors. The Company’s two distinct multi-specific DARPin® candidates, ensovibep and MP0423, were shown to protect well against these variants, as well as against multiple individual point mutations previously described. Further analyses in context of the full Brazilian P.1 lineage are ongoing. Of note, key spike mutations from the newly emerged variants identified in UK and SA, as well as from the variant detected in Brazil (lineage P.1), E484K, 69/70-deletion and N501Y, were tested individually and in the context of the full variants as described above, and were inhibited by the two DARPin® candidates. These results are highly encouraging as the Company continues the clinical development of these candidates. Full data can be found in the bioRxiv publication linked above.
Ensovibep is presently in its ongoing phase 1 study which is expected to provide data in the first quarter of 2021.

Media release