A phase II, single-arm study of denosumab in multiple myeloma patients with renal insufficiency.

Abstract

8520 Background: Bone destruction is a devastating consequence of multiple myeloma (MM). An unmet medical need exists for the management of skeletal complications in MM patients with renal insufficiency. Despite the effectiveness of intravenous bisphosphonates, their use is limited in situations where renal dysfunction is present. Denosumab is a fully human monoclonal IgG2 antibody to RANKL that has been shown to be non-inferior to zoledronic acid for SRE rates in MM (Raje, et al. Lancet Oncol). More importantly, it does not have the same renal toxicity as the bisphosphonates. We hypothesize that denosumab can be safely and effectively administered in MM patients with renal insufficiency to improve bone health. This may fill a gap in clinical care for bone-directed therapy in this patient population. Methods: This multi-center study will include forty adult patients with newly diagnosed or relapsed MM with a creatinine clearance of less than 30 mL/min (NCT02833610). All patients will receive a subcutaneous injection of denosumab 120 mg Q4W for a total of 12 cycles. In addition, it is required that all subjects receive daily vitamin D and calcium supplementation at standard doses (at least 2000 mg calcium citrate and1000 IU of vitamin D), unless documented hypercalcemia develops on study. The primary objective is to assess the effect of denosumab 120 mg Q4W on serum c-terminal telopeptide (sCTX). Secondary objectives include evaluation of safety and tolerability of denosumab in patients with renal insufficiency, incidence of hypocalcemia, effect on bone mineral density, effect on urinary n-terminal telopeptide, and proportion of patients who have a documented skeletal-related event. Results: At the time of this analysis, a total of 20 out of a planned 40 patients have been enrolled, including 9 women, 11 men. Of those treated, 8 patients have completed the planned 12 cycles of therapy. Hypocalcemia was observed in 7 (35%) patients. Four patients (20%) experienced grade 3 hypocalcemia, 3 (15%) grade 2 or less. Two patients developed osteonecrosis of the jaw, one (5%) grade 1 and one (5%) grade 4 event. Data for the analysis of the primary endpoint of sCTX levels will be presented. Conclusions: Investigation of denosumab in MM patients with renal insufficiency defined as a creatinine clearance less than 30 mL/min is ongoing. Early data support that denosumab can be safely administered in this population. However, incidence of hypocalcemia despite aggressive prophylactic calcium dosing underscores the importance of the trial to inform safe practice in this more fragile population. Clinical trial information: NCT02833610 .