Reduction of the Serum Levels of a Specific Biomarker of Cartilage Degradation (Coll2-1) by Hyaluronic Acid (KARTILAGE® CROSS) Compared to Placebo in Painful Knee Osteoarthritis Patients: The EPIKART Study, a Pilot Prospective Comparative Randomized Double Blind Trial

Background: Viscosupplementation is a symptomatic treatment of the knee osteoarthritis based on the intra-articular injection of hyaluronic acid (IAHA). Although many studies have investigated its effect on symptoms, few clinical studies have focused on its effects on biologicals markers of cartilage metabolism. In this study, we assessed the effect of an intra-articular injection of a reticulated hyaluronic acid compound on the level of a specific biomarker of type II collagen degradation. Methods: Eighty one patients with symptomatic knee osteoarthritis were included in this randomized placebo controlled trial testing a reticulated hyaluronic acid (HA) with mannitol (KARTILAGE® CROSS, 16 mg/ml, one single injection of 2.2 mL; IAHA) versus saline solution. Primary outcome was the percentage of patients with a reduction of at least 10 nmol/l of serum Coll2-1 between baseline and day 90 (D90, 3 months after injection). Secondary outcomes concerned clinical evaluation and tolerance to the study product. Results: A significant effect of IAHA was revealed by the sensitivity analysis of the decrease in cartilage marker. In the intention-to-treat population, the percentage of patients showing a decrease in the levels of serum Coll2-1 between inclusion and D90 showed was higher in HA (56.8%) than in placebo group (28.6%; P = 0.01). The same significant difference was observed between groups in the per protocol population (57.1% vs 29.0%; P = 0.02) corresponding to all patients having received the intra-articular injection (IA), being evaluated for the primary outcome on D-10 and D90, and with no major defined deviation. No significant differences between groups were observed on the changes in function (Lequesne index) or pain and on the number of adverse events. Conclusions: This is the first randomized double-blind placebo controlled trial showing that IA injection of reticulated HA with mannitol in knee osteoarthritis patients can reduce the serum levels of Coll2-1, a marker specific of type II collagen degradation. This finding suggests that IAHA may have a beneficial effect on cartilage degradation and that Coll2-1 could be used for the assessment of a single intra-articular treatment in clinical trials. Trial registration: NCT02951585; clinicaltrial.gov. Retrospectively registered on October 28, 2016. © 2017 The Author(s).