[Treatment of multiple myeloma with high-dose chemotherapy and transplantation of autologous hematopoietic stem cells and subsequent maintenance therapy with interferon alfa-2b or interferon alfa 2b and dexamethasone. Report of the ongoing study of the "4W" Czech Myeloma Group].

We report our results with high-dose chemotherapy in previously untreated multiple myeloma patients (4 courses of VAD chemotherapy, collection of PBSC after priming with cyclophosphamide, 5 g/m2, high-dose chemotherapy with melphalan, 200 mg/m2). Second transplantation was indicated only for patients who did not achieve remission after the first high-dose therapy (paraprotein lower than 25% of the pretreatment value). For the second transplantation melphalan (200 mg/m2) with methylprednisolone (1.5 g for 5 days) were used as conditioning regimen. After high-dose therapy all patients were randomized into two arms of maintenance therapy: interferon alpha-2b or sequential maintenance therapy (interferon alpha-2b for 3 months followed after 4 week pause by 40 mg of dexamethasone days 1-4, 10-13 and 20-23. The administration of interferon alpha was resumed four weeks after the last dexamethasone for next three months. The maintenance therapy continued for 48 months or until the progression. Fifty-five patients were enrolled in the study from January 1996 to August 1997. Thirty-five patients have undergone the first transplantation and 57% of them reached complete remission. There were 10% of non-responders after the first high-dose regimen. The mean time to reach white blood cell count above 1 x 10(9)/L after the application of high dose melphalan and platelets more than 50 x 10(9)/L were 12.2 (range 6-16 days) and 12.4 (range 0-25 days), respectively. Grade 4 mucositis according to SWOG classification requiring total parenteral nutrition was presented in 40% of the patients. The mean number of 1 unit of platelets and 2 units of packed red blood cells transfusions were given within the posttransplant period. Early transplant related mortality was 3%. This paper describes the response and tolerance of each particular step of therapy. The follow-up has been too short to evaluate event-free and overall survivals.