Reporting in the Annals of Rheumatic Diseases (December 2004), French researchers discovered that injections of the new hyaluronic acid compound called NRD101 have the same result for osteoarthritis (OA) of the knee as placebo injections. Hyaluronic acid is believed to restore elasticity to the synovial fluid that surrounds the knee joint, which is depleted in patients with OA of the knee. Yet, the effectiveness of this approach is unproven. Therefore, the researchers compared the safety and effectiveness of NRD101 with an orally administered drug, diacerein, in 300 patients. Previous research had shown that diacerein had a structural benefit in hip OA.
For the study, the participants were assigned to receive 3 courses of NRD101 injections, each involving 1 injection weekly for 3 weeks, every 3 months, along with a placebo capsule; placebo injections and diacerein twice daily; or placebo injections and capsules. During the 1-year study, the patients and clinicians evaluated symptoms, and x-rays were done to assess the effects of treatment on the knee structure at the beginning and end of the study.
The results of the study showed that the patients in all 3 groups had improvements of their symptoms. A small degree of structural weakening, however, occurred in each group. The researchers concluded that more research is needed to examine other treatment approaches using this route of administration.