Rxivist logo

Heparan sulfate (HS) is a cell surface polysaccharide recently identified as a co-receptor with the ACE2 protein for recognition of the S1 spike protein on SARS-CoV2 virus, revealing an attractive new target for therapeutic intervention. Clinically-used heparins demonstrate relevant inhibitory activity, but world supplies are limited, necessitating a synthetic solution. The HS mimetic pixatimod is synthetic drug candidate for cancer with immunomodulatory and heparanase-inhibiting properties. Here we show that pixatimod binds directly to the SARS-CoV-2 spike protein receptor binding domain (S1-RBD), altering its conformation and destabilizing its structure. Molecular modelling identified a binding site overlapping with the ACE2 receptor site. Consistent with this, pixatimod inhibits binding of S1-RBD to ACE2-expressing cells and displays a direct mechanism of action by inhibiting binding of S1-RBD to human ACE2. Assays with four different clinical isolates of live SARS-CoV-2 virus show that pixatimod potently inhibits infection of Vero cells at doses well within its safe therapeutic dose range. This demonstration of potent anti-SARS-CoV-2 activity establishes that synthetic HS mimetics can target the HS-Spike protein-ACE2 axis. Together with other known activities of pixatimod our data provides a strong rationale for its further investigation as a potential multimodal therapeutic to address the COVID-19 pandemic. ### Competing Interest Statement E.H. and K.D. are employees of Zucero Therapeutics. V.F., E.H. and K.D. are inventors on pixatimod patents.

Download data

  • Downloaded 1,697 times
  • Download rankings, all-time:
    • Site-wide: 13,379
    • In microbiology: 772
  • Year to date:
    • Site-wide: 50,381
  • Since beginning of last month:
    • Site-wide: 25,039

Altmetric data

Downloads over time

Distribution of downloads per paper, site-wide