Role of D(T)PACE-based regimens as treatment of multiple myeloma with extramedullary relapse or refractory disease

In multiple myeloma, atypical forms with extramedullary involvement exhibit poor survival. The poly-chemotherapeutic regimen D(T)-PACE has shown high activity in relapsed or refractory multiple myeloma. In this large monocentric retrospective study, we addressed the activity of D(T)-PACE-based regimens in 43 heavily pretreated patients with relapsed/refractory multiple myeloma and extramedullary disease. Median age at initiation was 57 years. Four patients had a t(4;14) translocation, 3 had a t(11;14) translocation and 7 had a del(17p). Extramedullary sites were mostly the skin (15 patients), central nervous system (10 patients), and thorax or abdomen (10 patients each). Overall response was achieved in 25 (58%) patients, including 6 (14%) with a complete response. Median progression-free survival was 5.0 months. Median overall survival was 9.0 months. Fourteen patients subsequently underwent stem-cell transplantation. Cytogenetics had no impact on response rate, overall survival and progression-free survival. In the era of several new immunotherapies, D(T)-PACE-based regimens still remain a useful treatment option for a selected group of heavily pretreated myeloma patients.