Denosumab in transfusion-dependent thalassemia osteoporosis: A randomized, placebo-controlled, double-blind phase 2b clinical trial

Abstract

Denosumab (DNM) is a fully human monoclonal antibody against the receptor activator of nuclear factor kappa-B ligand (RANKL) that has been licensed for the treatment of different types of osteoporosis. However, the prospective data for the evaluation of DNM efficacy on transfusion-dependent thalassemia (TDT)-induced osteoporosis are rather limited. Thus, we conducted a randomized, placebo-controlled, double-blind, phase 2b clinical trial to evaluate DNM in TDT osteoporosis. Patients were assigned to receive either 60 mg DNM (n = 32) or placebo (n = 31) subcutaneously on day 0 and 180 during a total of 12 months of follow-up. The percentage increase of L1-L4 bone mineral density was higher in the DNM group than the placebo group (5.92% ± 5.25% vs 2.92% ± 5.56%, respectively; P = .043), whereas the advantage of DNM regarding wrist bone mineral density was much higher compared with placebo (-0.26% ± 5.31% vs-3.92% ± 8.71%, respectively; P = .035). No grade 3 or 4 toxicity was observed. DNM reduced pain scores that remained unaltered in the placebo group. DNM showed a significant reduction of soluble RANKL (sRANKL), sRANKL/osteoprotegerin ratio, C-Telopeptide of collagen type I, tartrate-resistant acid phosphatase isoform-5b, and bone-specific alkaline phosphatase between baseline and the 12th month (P