Increased Valency Improves Inhibitory Activity of Peptides Targeting Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9)

Abstract

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a clinically validated target for treating hypercholesterolemia. Peptide‐based PCSK9 inhibitors have attracted pharmaceutical interest, but the effect of multivalency on bioactivity is poorly understood. Here we designed bivalent and tetravalent dendrimers, decorated with the PCSK9 inhibitory peptides Pep2‐8[RRG] or P9‐38, to study relationships between peptide binding affinity, peptide valency, and PCSK9 inhibition. Increased valency resulted in improved PCSK9 inhibition for both peptides, with activity improvements of up to 100‐fold achieved for the P9‐38‐decorated dendrimers compared to monomeric P9‐38 in in vitro competition binding assays. Furthermore, the P9‐38‐decorated dendrimers showed improved potency at restoring functional low‐density lipoprotein (LDL) receptor levels and internalizing LDL in the presence of PCSK9, demonstrating significant cell‐based activity at picomolar concentrations. This study demonstrates the potential of increasing valency as a strategy for increasing the efficacy of peptide‐based PCSK9 therapeutics.

Targeting proprotein convertase subtilisin/kexin type 9 (PCSK9): from bench to bedside

“… 428 Tombling et al designed a tetravalent dendrimer of PCSK9-targeted peptidomimetic tetra-P9-38 (IC50 = 180 pM) which fully restored the LDLR levels and LDL uptake in PCSK9-treated HepG2 cells. 429 Recently, two peptide PCSK9 inhibitors, MK-0616 (Ki = 2.39 pM) from Merck and NN-6434 (structure undisclosed) from Novo Nordisk, have progressed into phase 2 clinical trials to assess the effectiveness of hypercholesterolemia treatment (NCT05261126, NCT04992065) 382 (Table 1 ).…”

Recent Update on the Development of PCSK9 Inhibitors for Hypercholesterolemia Treatment

“…The same research team has recently enhanced the inhibitory activity of Pep2-8 ( 22) and P9-38 (25) by linking them to the dendrimer scaffold to raise the peptide valency, which improved the effective concentration of the inhibitor at the targeted site (Figure 13). 150 Among the synthesized analogues, tetravalent P9-38-tethered dendrimers (29) inhibited the PPIs between PCSK9 and LDLR with an IC 50 value of 0.00018 μM (∼100-fold enhanced activity over P9-38), whereas Bi−P9-38 (27) inhibits with an IC 50 value of 0.00033 μM.…”

Potent Lys Patch-Containing Stapled Peptides Targeting PCSK9

“…It was subsequently modified to generate new peptides with improved activity. [31][32][33][34] Besides these different approaches, advanced computational strategies allowed the discovery of small peptidomimetics that disrupt the PCSK9/LDLR PPI and inhibit PCSK9 activity. 35,36 All these studies point out the interest for peptides as an alternative strategy to small molecules or biologics for providing candidates able to potently inhibit the PCSK9-LDLR interaction.…”

“…Although Pep2-8 arouses great interest, it suffers from a fairly low binding affinity (0.7 μM) and neutralizes PCSK9 activity, with an IC 50 of 12.5 μM for LDLR restoration and 12.5 μM for LDL uptake in HepG2 cells. It was subsequently modified to generate new peptides with improved activity. − Besides these different approaches, advanced computational strategies allowed the discovery of small peptidomimetics that disrupt the PCSK9/LDLR PPI and inhibit PCSK9 activity. , …”