High-dose cyclophosphamide as an effective therapy for a patient with refractory multiple myeloma relapsing after autologous stem cell transplantation.

Alkylating agents are often used to treat patients with multiple myeloma (MM). However, it is not common for high-dose cyclophosphamide (CPM) therapy to be used as a treatment for MM. Herein, we report a case of refractory MM associated with hypercalcemia. We decided to give her high-dose CPM. After this treatment, the serum calcium level decreased and the tumor mass in the iliac bone was reduced. This therapy is potentially useful for patients with refractory MM.