- Duloxetine posted improvement in pain severity, but failed to meet the primary outcome, improvement in 24-hour average pain severity, in a placebo-controlled randomized controlled trial (RCT) of juvenile fibromyalgia (JFM).
Why this matters
- Findings may be used to gain the first drug approval for JFM, which affects 2.1%-6.1% of school children.
- Phase 3b RCT of patients aged 13-17 years with JFM diagnosed by Yunus and Masi criteria.
- Patients with a score of ≥4 on 24-hour average pain severity on the Brief Pain Inventory (BPI)-Modified Short Form were randomly assigned to placebo or starting dose of 30 mg duloxetine, with a target dose of 60 mg once-daily.
- The primary outcome was mean change in 24-hour average pain severity on the BPI from baseline to 13 weeks.
- Funding: Eli Lilly and Company.
- No difference between groups on the mean change in 24-hour average pain severity (−1.62 vs −0.97; P=.052).
- The duloxetine group was more likely to report ≥30% (52.22% vs 36.26%; P=.032) and ≥50% (40.00% vs 24.18%; P=.029) improvement in average pain severity on the BPI.
- No new safety signals emerged vs earlier studies of children and adults, with these most common adverse events consisting of nausea, headache, and vomiting.
- Yunus and Masi criteria not fully validated.