Walking a tightrope: clinical use of ibrutinib in mantle cell lymphoma in the elderly

Incidence and associated risk factors for invasive fungal infections and other serious infections in patients on ibrutinib

BACKGROUND

Ibrutinib is a small molecule tyrosine kinase inhibitor that blocks the activity of B cells and other immune effectors and is used in a variety of hematologic malignancies. There have been numerous reports of increased frequency of serious infections including invasive fungal infections (IFI) in patients on ibrutinib.

METHODS

Demographic and clinical features of all patients receiving ibrutinib at a single tertiary care center were collected from electronic medical records. Univariate and multivariate statistical analyses were performed to find out the factors associated with infection.

RESULTS

A total of 244 patients received ibrutinib for hematologic malignancies, of which 44 (18.0%) experienced ≥ 1 serious infection including 5 (2.0%) with IFI (1 pulmonary cryptococcosis, 4 pulmonary aspergillosis), 39 (16.0%) with bacterial infections and 8 (3.3%) with viral infections. Ten patients (4.1%) experienced multiple infections or co-infections while on ibrutinib and 10 (4.1%) expired or were transferred to hospice as a result of infection. In multivariate analysis risk factors that were less common in uninfected versus infected patients included advanced age (73 years vs. 77 years), Eastern Cooperative Oncologic Grade (ECOG) performance score ≥ 2 (6.5% vs. 31.8%) and concurrent use of steroids (4.5% vs. 20.5%) or other cytotoxic agents (0% vs. 4.6%).

CONCLUSIONS

There was a high rate of serious infection but relatively few IFI in patients receiving ibrutinib. Most patients who developed serious infections while on ibrutinib had additional predisposing risk factors including concurrent use of steroids or other cytotoxic agents, advanced age and frailty.

Targeted Drugs as Maintenance Therapy after Autologous Stem Cell Transplantation in Patients with Mantle Cell Lymphoma

The treatment landscape for mantle cell lymphoma (MCL) is rapidly evolving toward the incorporation of novel and biologically targeted pharmaceuticals with improved disease activity and gentler toxicity profiles compared with conventional chemotherapeutics. Upfront intensive treatment of MCL includes autologous stem cell transplantation (SCT) consolidation aimed at deepening and lengthening disease remission, but subsequent relapse occurs. Maintenance therapy after autologous SCT in patients with MCL in remission features lower-intensity treatments given over extended periods to improve disease outcomes. Targeted drugs are a natural fit for this space, and are the focus of considerable clinical investigation. This review summarizes recent advances in the field and their potential impact on treatment practices for MCL.