- Intra-articular injections of sprifermin, a recombinant human fibroblast growth factor, increases femorotibial joint cartilage thickness in knee osteoarthritis (KOA) at the highest doses, but leaves pain, stiffness, and function unchanged.
Why this matters
- If more evidence of benefit unfolds, sprifermin could become the first disease-modifying therapy for OA.
- 5-year, dose-finding, multicenter phase 2 trial of 549 patients aged 40-85 years with symptomatic, radiographic KOA of Kellgren-Lawrence grade 2/3.
- Participants were randomly assigned to 1 of 5 treatment groups:
- 100 μg sprifermin every 6 or 12 months.
- 30 μg sprifermin every 6 or 12 months.
- Placebo every 6 months.
- Each treatment episode consisted of weekly intra-articular injections over 3 weeks.
- Primary outcome: change in total femorotibial joint cartilage thickness assessed by quantitative MRI at 2 years.
- Funding: Merck KGaA.
- Groups 1 and 2 were the only ones to show significant improvement in femorotibial joint cartilage thickness over placebo (0.05 mm [95% CI, 0.03-0.07 mm] and 0.04 mm [95% CI, 0.02-0.06 mm], respectively).
- None of the groups showed improvement over placebo in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) total scores, as well as WOMAC subscores for pain, stiffness, and function.
- Durability of results unknown.