- Participants must have measurable disease, defined as at least one lesion that can be accurately measured in at least one dimension (longest diameter to be recorded for non-nodal lesions and short axis for nodal lesions) as >= 20 mm with conventional techniques or as >= 10 mm with spiral computed tomography (CT) scan, magnetic resonance imaging (MRI), or calipers by clinical exam; scans must have been performed within 4 weeks prior to registration; Note: for participants with Kaposi sarcoma, the following apply: at least five measurable cutaneous KS lesions or any number of lesions with systemic unresectable disease with no previous local radiation, surgical, or intralesional cytotoxic therapy that would prevent response assessment