Nelfinavir Mesylate in Treating Patients With Kaposi Sarcoma

PRIMARY OBJECTIVES: I. To determine the efficacy of a therapeutic escalation strategy consisting of standard dose nelfinavir (nelfinavir mesylate), followed by high dose nelfinavir, for the treatment of Kaposi sarcoma (KS) tumor lesions. With 36 evaluable participants, the null hypothesis will be rejected if 11 or more participants respond. SECONDARY OBJECTIVES: I. To evaluate the safety of high dose nelfinavir among participants with KS. II. To assess the effect of nelfinavir on Kaposi sarcoma-associated herpesvirus (KSHV) lytic gene expression in tumor tissue. III. To correlate nelfinavir and the primary active metabolite, M8, concentrations with tumor response, antiviral response, and adverse effects in participants with KS. IV. To assess the effect of nelfinavir on KSHV copy number in saliva. TERTIARY OBJECTIVES: I. To assess the effect of nelfinavir on KSHV copy number in PBMC and plasma. II. To assess the effect of nelfinavir on herpes simplex virus (HSV), cytomegalovirus (CMV) and Epstein-Barr virus (EBV) copy number in saliva. OUTLINE: STANDARD DOSE NELFINAVIR MESYLATE: Patients receive standard dose nelfinavir mesylate orally (PO) twice daily (BID) for 4 weeks in the absence of progressive disease (PD). Patients with PD at 4 weeks proceed to high-dose nelfinavir mesylate. At week 8, if there is stable disease (SD) or partial response (PR), patients advance to high-dose nelfinavir mesylate. Patients discontinue standard dose nelfinavir mesylate 4 weeks after documentation of complete response (CR). HIGH DOSE NELFINAVIR MESYLATE: Patients with PD continue to receive high-dose nelfinavir mesylate PO BID for 4 more weeks. If there is PD documented after 4 weeks at the high dose level, nelfinavir mesylate is discontinued. If there is SD or PR, patients continue receiving nelfinavir mesylate for 16 weeks. If there is CR, patients discontinue high-dose nelfinavir mesylate 4 weeks after documentation of CR. After completion of study treatment, patients are followed up at 8 weeks.