PCSK9 peptide inhibitors
Although at least 10 companies are chasing inhibitors of PCSK9 for decreasing low-density lipoprotein cholesterol, the compounds dominating the field are antibodies or siRNAs that require injection. Roche'sGenentech Inc. unit and a separate team from Pfizer Inc. and The University of Queensland are betting that peptides might provide an oral competitor and have identified short peptide fragments that inhibit binding of PCSK9 to its target.1,2 Optimizing the potency and stability for oral delivery is the next challenge.
Genentech is not disclosing plans for future development of the peptides. Pfizer did not reply to enquiries regarding future plans for its compounds.
The low-density lipoprotein receptor (LDLR) decreases circulating LDL cholesterol by binding the lipid at the hepatocyte cell surface, causing internalization of the LDL-LDLR complex. Inside the cells, LDLR dissociates from LDL and recycles to the cell surface, whereas the lipid is degraded by the lysosome.