Low-Dose Prednisone Decreases the Severity but Not the Frequency of Lenalidomide Associated Tumor Flare Feaction (TFR) in Chronic Lymphocytic Leukemia (CLL) Patients.

Introduction: Lenalidomide (L) is clinically active in pts with CLL. TFR is a common side effect of L, unique to CLL pts and is characterized by tender enlargement of lymph nodes (LN), spleen and/or liver with low-grade fever, rash and/or increase in white blood cell count. Onset is usually with 24 hours of first dose and it is rarely seen after the 1st cycle. The underlying etiology of TFR remains undetermined though clinical presentation is suggestive of an immune activation phenomenon. Diagnosis, management and effective prophylaxis of TFR is crucial for the pt care as it is associated with considerable morbidity and mimics disease progression. We investigated the effectiveness of low-dose prednisone prophylaxis in CLL pts treated with L.

Method & Results: Forty five pts (36 male, 9 female), median age 64 years (range 42–75) with rel/ref CLL were enrolled on a phase II clinical trial. Single agent L (max. dose 25mg/day) was given to all pts enrolled. No prophylaxis was given to the first 29 pts (group A). Subsequently 16 pts (group B) were treated with prednisone 20mg PO QD × 5 days followed by 10mg PO QD × 5 days, starting day 1 of treatment. Median age was 64 years (range 42–75) with 36M and 9F. Stage III/IV disease was noted in 64% (n=18) of the pts. Twenty four (83%) pts in group A and 13 (81%) in group B developed TFR with > grade II TFR was seen in 31% and 6%, respectively. Among pts with TFR, 4 achieved complete remission (CR) and had grade > 2 reaction vs. 19 pts with a < partial remission who had a median of grade 1 (range 1–2) TFR.

Conclusion: Although the sample size investigated is small, we observed that use of oral prednisone prophylaxis decreased the severity but not the overall incidence of TFR. We therefore recommend that low-dose prednisone be considered for lenalidomide associated TFR in patients with CLL.