Prednisone (P) prophylaxis decreases incidence and severity of lenalidomide (L) induced flare reaction (flr) in patients with relapse (rel) or refractory (ref) chronic lymphocytic leukemia

18512 Background: Flare reaction (flr) is a new side effect unique to CLL pts treated with immunomodulating agents both thalidomide (T) and L. It is characterized by tender swelling of disease involved lymph nodes (LN), spleen, rash, low-grade fever and/or increase in absolute lymphocyte counts (ALC). Underlying biologic process remains unknown though it is postulated to be mediated through activation of immune effector cells and/or change in serum concentration of pro-inflammatory cytokines. In a phase II clinical trial of L in rel/ref CLL pts we noted a high incidence of flr. Here we report treatment schema for flr and a new preventive approach employed in this study. Methods: A total of 35 pts are enrolled. No prophylaxis given to initial cohort (A). Pts were treated at onset of symptoms with (1) ibuprofen (Ib) 600 mg po q6 hours (2) oxycodone (oxy) 5–10 mg po prn q 6 hours. In subsequent cohort (B) we are investigating prophylactic use of P 20 mg PO QD starting day −1 × 5 days followed by 10 mg QD × 5...