Oral idarubicin as a single agent therapy in patients with relapsed or resistant multiple myeloma

The established treatment for multiple myeloma (MM) comprises induction wit h infusional chemotherapy, high dose chemotherapy (HDC) and autologous tran splantation followed by maintenance interferon. On relapse, patients (pts) are reconsidered for this however some are unsuitable and in this situation the therapeutic options are limited. Between June 1995 and May 1997, 14 pt s with previously treated relapsed or refractory MM were recruited. Using a prospective database, the tolerability and efficacy of chronic low dose or al idarubicin was evaluated. The median age of pts was 63 years. All had re ceived previous anthracycline in the form of infusional cVAMP chemotherapy. 11/14 had received previous HDC, Median time from diagnosis to commencing idarubicin was 77 months. 10mg idarubicin was administered 3 times/week for 3 weeks of a 5 week cycle. The maximum number of courses was 6, Three pts completed 6 courses, 5 pts 3 courses, 2 pts 2 courses and 4 pts 1 course. T he reasons for stopping treatment were death due to progressive disease (PD ) in 7 pts, persistent thrombocytopenia in 2 pts, PD in 1 pt and 1 pt suffe red a cerebral infarction not considered to be related to the idarubicin th erapy. Two pts showed evidence of response, neither amounting to a partial response. One had stabilisation of paraprotein with a reduction in bone mar row infiltration (47% to 7% plasma cells), the other had a reduction in bon e marrow infiltration after 3 course but an increase after 6 courses. In to tal forty-one courses of treatment were administered. Grade 3/4 haematologi cal toxicities were noted in a minor fraction of cases and were as follows: anaemia 6/41, neutropenia 10/41 and thrombocytopenia 11/41. Our data there fore shows a minor response in 2/14 (14%) of heavily pretreated patients wi th MM, without eveidence of severe toxicity. It provides the rationale for using oral idarubicin as either single agent or in combination therapy for patients earlier on in their disease course especially if they are unsuitab le for standard therapy.