Upon initiation of idelalisib, a temporary increase in lymphocyte counts (., ≥ 50% increase from baseline and above absolute lymphocyte count of 5,000/mcL) has been observed. This occurs in approximately two-thirds of patients with CLL treated with idelalisib monotherapy and one-fourth of patients with CLL treated with idelalisib combination therapy. The onset of isolated lymphocytosis typically occurs during the first 2 weeks of idelalisib therapy and is often associated with reduction of lymphadenopathy. This observed lymphocytosis is a pharmacodynamic effect and should not be considered progressive disease in the absence of other clinical findings.
In a phase II clinical trial, Martinez et al (2009) examined the safety and effectiveness of alemtuzumab in treating steroid-refractory acute GVHD (aGVHD) grade II or higher after stem cell transplantation. A total of 10 adult patients (6 with aGVHD grade III and 4 with aGVHD grade IV) were included in the study. Nine patients had gastrointestinal tract involvement, 7 had skin involvement, and 5 had liver involvement. Five patients responded to treatment, 2 with CR and 3 with partial response. Eight infectious events (4 of grade 3 to 4) and 7 CMV re-activations were observed. Six patients had grade 3 to 4 cytopenia. All 10 patients died (7 resulting from aGVHD progression, 2 from severe infection, and 1 from to leukemia relapse), at a median of 40 days (range of 4 to 88 days) after alemtuzumab treatment. Overall, these findings suggested that steroid-refractory aGVHD may be improved by treatment with alemtuzumab, but that this treatment does not overcome the dismal prognosis of patients with severe aGVHD, demonstrating the need for alternative therapies to treat this complication.