The safety, tolerability, and efficacy of
fasinumab (
REGN475), a fully human
monoclonal antibody against
nerve growth factor, was evaluated for the treatment of
pain in patients with
osteoarthritis (OA) of the knee. This was a 24-week, double-blind, placebo-controlled, parallel-group, repeat-dose, exploratory study. Eligible patients 40 to 75 years of age with a diagnosis of OA of the knee and moderate to severe
pain were randomized 1:1:1:1 to intravenous
fasinumab 0.03, 0.1, or 0.3 mg/kg or placebo and received study drug on day 1 and day 57.
Pain intensity was recorded daily using the numeric rating scale. Safety and tolerability, assessed by the incidence of treatment-emergent adverse events (TEAEs), was the primary study endpoint. Secondary study endpoints included the change from baseline in daily walking knee
pain and the assessment of
pain, function, and stiffness using the Western Ontario and McMaster
Osteoarthritis (WOMAC) index. Baseline characteristics were similar among treatment groups (N=217). After 24 weeks, the incidence of TEAEs ranged from 66.1% to 75.0% in the
fasinumab groups vs. 63.6% for placebo. The most common TEAEs included
arthralgia,
hyperesthesia,
myalgia, peripheral
edema, and joint swelling. Discontinuation for TEAEs occurred in 5.6% of
fasinumab patients and 3.7% of placebo patients. All 3 doses of
fasinumab were associated with significant (P<.05) improvements compared with placebo in walking knee
pain and WOMAC total and subscale scores.
Fasinumab was generally well tolerated, and was associated with a significant reduction in walking knee
pain and an improvement in function for up to 8 weeks.