A New Induction Combination Therapy (ThalDoDex) for Multiple Myeloma. Preliminary Results of a Phase II Study

Abstract 5030

Treatment for multiple myeloma is dramatically changed over the past 5 years. Thalidomide containing regimen is now widely accepted as standard treatment for multiple myeloma in first line. The mechanism of action and the toxicity profile of Thalidomide, make this drug suitable for combination with chemotherapeutic agents.

We report clinical results in terms of efficacy and safety of an antracycline containing regimen [liposomal doxorubicin (Myocet), Dexamethasone and Thalidomide (ThalDoDex)] In multiple myeloma before autologous transplantation.

From June 2007 to June 2010, ThalDoDex was delivered to 28 previously untreated multiple myeloma patients. Median age was 59 years (range 42–71); 5 patients were staged IIA and 21 patients staged IIIA and 2 IIIB; 15, 8 and 5 patients were ISS I, II, III respectively. Fifteen patients presented IgG monoclonal immunoglobuline, 6 IgA, 5 patients light chains myeloma, 1 patient plasma cell leukaemia and one other secretory multiple myeloma. Treatment schedule was as follows: Thalidomide 100 mg/day for 14 days then 200mg/day until the end of induction; Dexamethasone 40 mg days 1à4; Liposomal Antracycline (MYOCET) 50 mg/sqm day 1 for 4 cycles at 4 weekly intervals. LMWH 100UI/kg/day was added to all patients for DTV prophylaxis. All patients were considered for a peripheral blood stem cell transplantation program according to age and clinical outcome.

Twenty-five patients are evaluable for response. Fifteen patients (60%) achieved a CR (1 pt) or a nCR (5 pts), or a VGPR (9 pts) with an overall response rate of 80% (CR, nCR, VGPR, PR).

Six patients developed transient febrile neutropenia which solved with antibiotics. During neutropenia two patients developed pneumonia treated with appropriate antimicrobial therapy. No major haematological toxicity was observed. No neurological toxicity or thrombotic event was reported.

Our experience suggests that ThalDoDex is effective and safe as induction phase in newly diagnosed multiple myeloma patients. The clinical results are similar to those reported with other Thalidomide containing regimens. Liposomal doxorubicin in combination with Thalidomide and steroid may induce an important rate of CR and nCR as requested for the best clinical result of subsequent autologous transplant procedure. Our combination regimen avoiding alkylating agents and proteosome inhibitors may deserve the use at eventually subsequent relapse.