CLINICAL TRIALS AND OBSERVATIONS Phase 2 study of pegylated liposomal doxorubicin in combination with interleukin-12 for AIDS-related Kaposi sarcoma

Thirty-six patients with AIDS-associated Kaposi sarcoma (KS) requiring chemotherapy were treated for six 3-week cycles of pegylated liposomal doxorubicin (20 mg/m2) plus interleukin-12 (IL-12; 300 ng/kg subcutaneously twice weekly), followed by 500 ng/kg subcutaneous IL-12 twice weekly for up to 3 years. All received highly active antiretroviral therapy (HAART). Twenty-two had poor-prognosis KS (T1S1). Thirty patients had a major response, including 9 with complete response, yielding an 83.3% major response rate (95% confidence interval: 67.2%-93.6%). Median time to first response was 2 cycles. Median progression was not reached at median potential follow-up of 46.9 months. Of 27 patients with residual disease when starting maintenance IL-12, 15 had a new major response compared with this new baseline. The regimen was overall well tolerated; principal toxicities were neutropenia, anemia, transaminitis, and neuropsychiatric toxicity. Patients had increases in serum IL-12, interferon gamma, and inducible protein-10 (IP-10), and these remained increased at weeks 18 and 34. The regimen of IL-12 plus liposomal doxorubicin yielded rapid tumor responses and a high response rate in patients with AIDS-KS receiving HAART, and responses were sustained on IL-12 maintenance therapy. A randomized trial of IL-12 in this setting may be warranted. This study is registered at http://www.clinicaltrials.gov as no. NCT00020449. (Blood. 2007;110: 4165-4171)