J. Martin Broto, Ira Jacobs, R. Henshaw, M. Dominkus, Emanuela Palmerini, David Thomas, Robert J. Grimer, Jacob Engellau, Peter Reichardt, J.-Y. Blay, Yi Qian, Piotr Rutkowski, Y. Zhao, Keith M. Skubitz, Edwin Choy, Shanta Chawla, J. Blay, S. P. Chawla, J. Martin Broto, E. Choy, M. Dominku, J. Engellau, R. Grimer, R.M. Henshaw, E. Palmerini, P. Reichardt, P. Rutkowski, K. M. Skubitz, D. M. Thoma, Y. Zhao, Y. Qian, and I. A. Jacobs
10034 Background: GCTB, an osteolytic tumor causing skeletal morbidity, contains osteoclast-like giant cells and mononuclear cells expressing RANKL, a mediator of osteoclast activation. Denosumab binds RANKL, inhibiting osteoclast activity. In an initial phase 2 study, 86% of subjects with GCTB responded to denosumab. We report data from a prespecified 12‐month interim analysis in a second open-label phase 2 study of denosumab in GCTB. Methods: Subjects with surgically unsalvageable GCTB (cohort 1) or salvageable GCTB with planned surgery (cohort 2) received subcutaneous denosumab 120 mg every 4 weeks, with a 120 mg loading dose on days 8 and 15. The primary objective was to evaluate the safety of denosumab. The analysis also included subjective assessments of disease progression and the proportion of cohort-2 subjects for whom surgery was delayed, reduced in scope, or not required. Safety analyses included all subjects who received denosumab; efficacy analyses included subjects who received denosumab for...