Efficacy, safety and tolerability of GSK3858279, an anti-CCL17 monoclonal antibody and analgesic, in healthy volunteers and patients with knee osteoarthritis pain: a phase I, randomised, double-blind, placebo-controlled, proof-of-mechanism and proof-of-concept study.

Objectives: The objective of this study was to evaluate efficacy, safety and tolerability of the first-in-class, anti-CCL17 monoclonal antibody, GSK3858279, in treating knee osteoarthritis (OA) pain.

Methods: This was a phase I, randomised, placebo-controlled, two-part, proof-of-mechanism and proof-of-concept study. In part A, healthy participants were randomised 3:1 to receive GSK3858279 as either single intravenous (0.1-10 mg/kg) doses, a subcutaneous (3 mg/kg up to 240 mg maximum) dose, or placebo, to evaluate safety and tolerability. In part B, participants with knee OA pain were randomised 1:1 to receive weekly subcutaneous 240 mg GSK3858279, or placebo, for 8 weeks, to assess safety and change from baseline (CFB) in average and worst knee pain intensity. Exploratory endpoints included CFB in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain, function and stiffness scores.

Results: GSK3858279 demonstrated greater median CFB (95% credible interval (CrI)) in average and worst knee pain intensity versus placebo (average, -1.18 (-2.15, -0.20); worst, -1.09 (-2.29, 0.12)) at week 8. Median CFB (95% CrI) for GSK3858279 versus placebo in WOMAC pain and function scores were -1.41 (-2.35, -0.46) and -1.29 (-2.28, -0.29), respectively, at week 8. Overall, 72% (26/36; part A) and 88% (21/24; part B) of participants receiving GSK3858279 experienced adverse events (AEs); with nasopharyngitis being the most common in part A and injection site reactions in part B. No serious AEs or deaths were observed.GSK3858279 improved pain intensity and WOMAC pain and function scores in adults with knee OA pain and demonstrated favourable safety and tolerability in both healthy participants and adults with knee OA pain.