The risk of infections in multiple myeloma before and after the advent of novel agents: a 12-year survey.

Infections represent a major cause of morbidity and mortality in multiple myeloma and are linked to both therapy- and disease-related factors. Although it has been suggested that the rate of infections increased since the introduction of novel agents, controversies still exist. To better assess the risk factors associated with infections in the era of novel agents, we conducted a large retrospective analysis of 479 myeloma patients treated at Jena University Hospital over a period of 12 years. During their disease history, 65% of patients developed at least one infection, and 37% of therapies were associated with at least one infectious episode. The rate of infections was constant over the years, with no increase in infectious complications after the routine implementation of novel agents. Infections were mainly bacterial and strongly associated with high disease burden, relapsed disease, and treatment with high-dose chemotherapy. Varicella zoster virus (VZV) reactivations occurred late during treatment (median time between high-dose chemotherapy and VZV reactivation 6 months, range 0-44 months), and fewer patients developed a VZV reactivation after 2009 (p = 0.001). Infections are still one of the major causes of morbidity in myeloma patients, and prophylactic measures are urgently needed to reduce this potentially lethal complication.