Efficacy and Safety of Stealth Liposomal Doxorubicin in AIDS-related Kaposi's Sarcoma. The International SL-DOX Study Group

The utility of current chemotherapeutic regimens in the treatment of AIDS-related Kaposi's sarcoma (AIDS-KS) is often compromised by both limited efficacy and substantial toxicity. Pegylated (Stealth) liposomal doxorubicin hydrochloride (SL-DOX) has been demonstrated specifically to deliver high concentrations of doxorubicin to Kaposi's sarcoma (KS) lesions. This phase II study was performed to evaluate the efficacy and safety of SL-DOX in the treatment of moderate to severe AIDS-KS. Patients were treated biweekly with 10, 20, or 40 mg m-2 SL-DOX. Tumour response was assessed according to AIDS Clinical Trials Groups (ACTG) criteria before each cycle. Best response was determined for 238 patients and was achieved after a mean of 2.3 cycles (range 1-20). Fifteen patients (6.3%) had a complete response to SL-DOX, 177 (74.4%) had a partial response, 44 (18.5%) had stable disease and two (0.8%) had disease progression. SL-DOX was well tolerated: ten patients discontinued therapy because of adverse events, in four cases because of neutropenia. Grade 3 or 4 neutropenia occurred after 281 of 2023 cycles (13.9%) but involved 137 of 240 patients (57.1%) for whom data were available. SL-DOX has substantial activity in AIDS-KS. Best response is typically seen after fewer than three cycles of chemotherapy and in some cases may be prolonged. The most important adverse event is neutropenia, which occurs after a minority of cycles but which may occur in over half of all patients.