This post comes from Fred Nelson, MD, an orthopaedic surgeon in the Department of Orthopedics at Henry Ford Hospital and a clinical associate professor at Wayne State Medical School. Some of Dr. Nelson’s tips go out weekly to more than 3,000 members of the Orthopaedic Research Society (ORS), and all are distributed to more than 30 orthopaedic residency programs. Those not sent to the ORS are periodically reposted in OrthoBuzz with the permission of Dr. Nelson.
To date, we have found only one documented disease-modifying intervention that slows the progression of knee osteoarthritis (OA)—weight loss.1 There are few positive findings about drugs or other therapeutic interventions that might prolong the life of the human joint. However, sprifermin, a recombinant human fibroblast growth factor that can be genetically engineered from bacteria, has been tested in a randomized proof-of-concept trial as an intra-articular injection in humans,2 with modestly promising results.
In a very recent study on the effect of sprifermin and several other potentially disease-modifying compounds on bovine chondrocytes, researchers used 3D cultures to assess chondrocyte proliferation and/or extracellular matrix production.3 All of the growth factors evaluated, including sprifermin, resulted in elevated markers of anabolic chondrocyte activity. For the most part, cyclic doses were more effective than continuous doses over 4 weeks. Of importance, only sprifermin decreased type I collagen expression and had no hypertrophic effects. The authors conclude in the abstract that “these results confirm that sprifermin is a promising disease-modifying OA drug.”
In a 5-year randomized human dose-finding trial,4 patients with symptomatic knee OA were divided into 5 groups, as follows:
- 100 μg of sprifermin administered every 6 months (n = 110)
- 100 μg of sprifermin administered every 12 months (n = 110)
- 30 μg of sprifermin administered every 6 months (n = 111)
- 30 μg of sprifermin administered every 12 months (n = 110)
- Placebo injections administered every 6 months (n = 108)
The greatest changes in the primary endpoint—increased total femorotibial joint cartilage thickness from baseline to 2 years—was 0.05 mm (95% CI, 0.03 to 0.07 mm) in the group that received 100 μg of sprifermin every 6 months and 0.04 mm (95% CI, 0.02 to 0.06 mm) in the group that received 100 μg of sprifermin every 12 months. However, compared with the placebo group, those receiving sprifermin had no statistically different change in WOMAC scores. On average, 40% of all the patients in the study experienced arthralgia associated with the injections.
More certainty about the efficacy, safety, and durability of sprifermin may come when data from the remaining 3 years of this study are analyzed (see ClinicalTrials.gov identifier NCT01919164).
- Gersing AS, Solka M, Joseph GB, Schwaiger BJ, Heilmeier U, Feuerriegel G, Nevitt MC, McCulloch CE, Link TM. Progression of cartilage degeneration and clinical symptoms in obese and overweight individuals is dependent on the amount of weight loss: 48-month data from the Osteoarthritis Initiative. Osteoarthritis Cartilage. 2016 Jul;24(7):1126-34. doi: 10.1016/j.joca.2016.01.984. PMID: 26828356 PMCID: PMC4907808.
- Lohmander LS, Hellot S, Dreher D, et al. 2014. Intraarticular sprifermin (recombinant human fibroblast growth factor 18) in knee osteoarthritis: a randomized, double-blind, placebo-controlled trial. Arthritis Rheumatol. 66(7):1820–31.
- Müller S, Lindemann S, Gigout A. Effects of sprifermin, IGF1, IGF2, BMP7 or CNP on bovine chondrocytes in monolayer and 3D culture. J Orthop Res. 2019 Oct 14. doi: 10.1002/jor.24491. [Epub ahead of print] PMID: 31608492.
- Hochberg MC, Guermazi A, Guehring H, Aydemir A, Wax S, Fleuranceau-Morel P, Bihlet AR, Byrjalsen I, Andersen JR, Eckstein F. Effect of Intra-Articular Sprifermin vs Placebo on Femorotibial Joint Cartilage Thickness in Patients With OsteoarthritisThe FORWARD Randomized Clinical Trial. JAMA. 2019;322(14):1360-1370. doi:10.1001/jama.2019.14735