Discovery and Characterization of a Potent Interleukin-6 Binding Peptide with Neutralizing Activity In Vivo

  • PLoS One. 2015 Nov 10;10(11):e0141330. doi: 10.1371/journal.pone.0141330.
Sheila Ranganath  1 ,  Ashok Bhandari  2 ,  Nicole Avitahl-Curtis  3 ,  Jaimee McMahon  4 ,  Derek Wachtel  5 ,  Jenny Zhang  4 ,  Christopher Leitheiser  6 ,  Sylvie G Bernier  1 ,  Guang Liu  1 ,  Tran T Tran  7 ,  Herodion Celino  2 ,  Jenny Tobin  3 ,  Joon Jung  8 ,  Hong Zhao  6 ,  Katie E Glen  4 ,  Chris Graul  3 ,  Aliesha Griffin  4 ,  Wayne C Schairer  6 ,  Carolyn Higgins  5 ,  Tammi L Reza  9 ,  Eva Mowe  4 ,  Sam Rivers  3 ,  Sonya Scott  4 ,  Alex Monreal  1 ,  Courtney Shea  3 ,  Greg Bourne  4  7 ,  Casey Coons  6 ,  Adaline Smith  9 ,  Kim Tang  3 ,  Ramya A Mandyam  4 ,  Jaime Masferrer  3 ,  David Liu  10 ,  Dinesh V Patel  2 ,  Angelika Fretzen  6 ,  Craig A Murphy  4  7 ,  G Todd Milne  1 ,  Mark L Smythe  4  7 ,  Kenneth E Carlson  1
Affiliations
  • 1. Discovery Biology, Ironwood Pharmaceuticals, Cambridge, MA, United States of America.
  • 2. Chemistry, Protagonist Therapeutics, Milpitas, CA, United States of America.
  • 3. Discovery Pharmacology, Ironwood Pharmaceuticals, Cambridge, MA, United States of America.
  • 4. Institute for Molecular Biosciences, The University of Queensland, Brisbane, Australia.
  • 5. DMPK, Ironwood Pharmaceuticals, Cambridge, MA, United States of America.
  • 6. Pharmaceutical Development, Ironwood Pharmaceuticals, Cambridge, MA, United States of America.
  • 7. Protagonist Pty Ltd, Therapeutics Pty Ltd, Brisbane, Australia.
  • 8. Chemistry, Ironwood Pharmaceuticals, Cambridge, MA, United States of America.
  • 9. Discovery Toxicology, Ironwood Pharmaceuticals, Cambridge, MA, United States of America.
  • 10. Biology, Protagonist Therapeutics, Milpitas, CA, United States of America.
PMID: 26555695 DOI: 10.1371/journal.pone.0141330
Abstract

Interleukin-6 (IL-6) is an important member of the cytokine superfamily, exerting pleiotropic actions on many physiological processes. Over-production of IL-6 is a hallmark of immune-mediated inflammatory diseases such as Castleman's Disease (CD) and rheumatoid arthritis (RA). Antagonism of the interleukin IL-6/IL-6 receptor (IL-6R)/gp130 signaling complex continues to show promise as a therapeutic target. Monoclonal antibodies (mAbs) directed against components of this complex have been approved as therapeutics for both CD and RA. To potentially provide an additional modality to antagonize IL-6 induced pathophysiology, a peptide-based antagonist approach was undertaken. Using a combination of molecular design, phage-display, and medicinal chemistry, disulfide-rich peptides (DRPs) directed against IL-6 were developed with low nanomolar potency in inhibiting IL-6-induced pSTAT3 in U937 monocytic cells. Targeted PEGylation of IL-6 binding peptides resulted in molecules that retained their potency against IL-6 and had a prolongation of their pharmacokinetic (PK) profiles in rodents and monkeys. One such peptide, PN-2921, contained a 40 kDa polyethylene glycol (PEG) moiety and inhibited IL-6-induced pSTAT3 in U937 cells with sub-nM potency and possessed 23, 36, and 59 h PK half-life values in mice, rats, and cynomolgus monkeys, respectively. Parenteral administration of PN-2921 to mice and cynomolgus monkeys potently inhibited IL-6-induced biomarker responses, with significant reductions in the acute inflammatory phase proteins, serum amyloid A (SAA) and C-reactive protein (CRP). This potent, PEGylated IL-6 binding peptide offers a new approach to antagonize IL-6-induced signaling and associated pathophysiology.