BACKGROUND

Lenalidomide, an immunomodulatory agent, has activity in lymphoproliferative disorders. The authors, therefore, evaluated its effects on T-cell immunophenotype and cytokine production in patients with chronic lymphocytic leukemia (CLL).

METHODS

To study the immunomodulatory effects of lenalidomide in CLL, the authors recruited 24 patients with untreated CLL enrolled in a phase 2 clinical trial of lenalidomide and obtained peripheral blood specimens for immunologic studies consisting of enumeration of T cells and assessing their ability to synthesize cytokines after activation through T-cell receptor (TCR).

RESULTS

After 3 cycles of therapy, patients had a significant reduction in percentage (%) and absolute lymphocyte count (ALC) and an increase in percentage of T cells, percentage of activated CD8(+) T cells producing IFN-γ, and percentage of regulatory T (T(R) ) cells when compared with their respective levels before treatment. After 15 cycles of treatment, responder patients had significant reduction in percentage of lymphocytes and ALC, percentage of activated CD4(+) T cells producing IL-2, IFN-γ, or TNF-α, and percentage of T(R) cells when compared with their perspective levels after 3 cycles of treatment. Furthermore, the numbers of activated CD4(+) T cells producing IL-2, IFN-γ, or TNF-α, activated CD8(+) T cells producing IFN-γ, and T(R) cells normalized to the range of healthy subjects.

CONCLUSIONS

Treatment with lenalidomide resulted in the normalization of functional T-cell subsets in responders, suggesting that lenalidomide may modulate cell-mediated immunity in patients with CLL.