Strontium ranelate delays radiographic progression of knee osteoarthritis

   Strontium ranelate (SrRan) in doses of 1g/day and 2g/day delays the radiographic progression of knee osteoarthritis (OA), evidencing a structure-modifying effect, according to data from the multinational Strontium Ranelate in Knee Osteoarthritis Trial (SEKOIA).

   This structural effect is translated clinically into a lower number of patients having a radiological progression predictive of OA-related surgery, suggesting that SrRan could reduce the number of patients needing knee surgery in the long term. Further, the structural effect was accompanied by symptom improvement at the dose of 2g/day.

    SEKOIA is a double-blind, placebo-controlled, randomized, three-year study involving 1683 patients with symptomatic primary knee OA (Kellgren and Lawrence [KL] grade 2 or 3, joint space width [JSW] 2.5-5 mm) randomly allocated to SrRan 1g/day or 2g/day, or placebo. In the ITT set (n=1371), SrRan was associated with less progression of cartilage degradation; decrease in JSW of -0.23 +/-0.56 mm with 1g/day, -0.27 +/-0.63 mm with 2g/day, and -0.37 +/-0.59 mm with placebo. The estimated differences (SE) were 0.14 (0.04), P <0.001 for 1g/day, and 0.10(0.04), P=0.018 for 2g/day. According to the investigators, greater reductions in total WOMAC score (P =0.045), pain (P=0.028) and physical function subscore (P=0.099), and knee pain (P=0.065) were observed with SrRan 2 g/day. SrRan was well tolerated; 86%, 88%, and 87% reported an emergent adverse event (EAE) in the SrRan 1g/day, 2g/day, and placebo group respectively. Seventeen percent of the patients in each group reported a serious EAE: one EAE in each SrRAn group and three in the placebo group led to death.