Infectious complications in patients with multiple myeloma treated with new drug combinations containing thalidomide.

The literature provides scant data concerning infectious complications and their effect on the outcome of patients with multiple myeloma (MM) treated with new drug combinations. Despite no substantial myelotoxic effect, thalidomide increases the risk of severe infections in patients with MM. We studied 202 patients who received regimens containing thalidomide in order to assess the time, type, outcome, and factors affecting development of severe infections, role of antibiotic prophylaxis, and effect of severe infections on final outcome. Thirty-eight patients (19%) developed a severe infection early during induction therapy and most infections were pneumonia. Only one patient died due to septic shock during neutropenia. No significant differences were reported in terms of progression-free survival (PFS) and overall survival (OS) between patients developing a severe infection and those who did not. Multivariate analysis determined a monoclonal component >3 g/dL and platelets <130 ,000/μL as factors associated with increased risk of severe infection. Primary antibiotic prophylaxis significantly decreased the probability of severe infection only in patients having both the above risk factors. Patients with MM receiving thalidomide combinations with high tumor burden are at high risk of developing severe infections and require primary antibiotic prophylaxis, whereas in other patients it is questionable. However, patient final outcome was not affected by infection development.