Pomalidomide Treatment in Patients With Kaposi Sarcoma

PRIMARY OBJECTIVE: I. To assess the proportion of participants with Kaposi sarcoma (KS) (with or without human immunodeficiency virus \[HIV\], regardless of previous treatment status) treated with pomalidomide who respond to treatment with a durable response (i.e., response duration of at least one year). SECONDARY OBJECTIVES: I. To measure the overall response rate (ORR) and report 95% confidence intervals in the overall study population. Ia. To measure the ORR in the HIV positive study population. Ib. To measure the ORR in the HIV unrelated study population. II. To estimate the ORR in subgroups of KS in regard to HIV and previous treatment status. III. To assess the safety of pomalidomide therapy. IV. To describe changes in visceral disease among those presenting with evaluable visceral disease. V. To assess response duration in participants treated with pomalidomide. EXPLORATORY OBJECTIVES: I. To assess the effect of pomalidomide treatment on the tumor microenvironment and explore the relationship with clinical response. II. To describe the effects of pomalidomide on CD4 lymphocyte counts and HIV viral load in HIV positive (+) participants. III. To assess the effect of pomalidomide treatment on serum biomarkers and explore the relationship with clinical response. IV. To assess Kaposi's sarcoma-associated herpesvirus (KSHV) viral copy number in plasma and explore whether changes correlate with clinical outcome. V. To assess the effects of pomalidomide on viral and cellular transcription in KS tumor biopsies and explore the relationship with clinical response. VI. To biobank clinical samples for future potential studies on the immune phenotype and viral and cellular transcription and to explore the relationship with clinical response. OUTLINE: Patients receive pomalidomide orally (PO) once daily (QD) on days 1-21. Treatment repeats every 28 days for up to 12 cycles in the absence of disease progression or unacceptable toxicity. After 12 cycles, patients with complete response (CR) or partial response (PR) continue pomalidomide for an additional 12 cycles with the option to continue thereafter in the absence of disease progression or unacceptable toxicity. After 12 cycles, patients with stable disease may continue pomalidomide for an additional 12 cycles in the absence of disease progression or unacceptable toxicity. Patients undergo chest x-ray imaging throughout the trial. Patients may undergo computed tomography (CT) as clinically indicated. Patients also undergo blood sample collection and may optionally undergo tissue biopsy during screening and on the trial. After completion of study treatment, patients are followed up every 6 months for up to 5 years.