UC San Diego

Kaposi sarcoma (KS) is the most common malignancy in patients with human immune-deficiency virus (HIV) and presents a treatment conundrum because of its variable natural history. Lenalidomide is a drug that has immune- modulatory, anti-neoplastic, and anti-angiogenic properties. It is used in the treatment of myelodysplastic disease and multiple myeloma, but its in vivo effects on peripheral blood immune activity is not fully explored. In this preliminary report from a Phase I/II trial of lenalidomide in the treatment of AIDS-associated KS, we found that lenalidomide increased the number and percentage of T-regulatory-phenotype cells in the peripheral blood. In patients with measurable regression of KS lesion size as well as number of lesions, there was also an observable accumulation in FOXP3-expressing cells in the KS lesion. We speculate from these findings that lenalidomide may be useful in the treatment of KS in part because of its anti-angiogenic activity, which is correlated with boosting T-regulatory cell frequency in the peripheral blood