Beta-interferon therapy in patients with poor-prognosis Kaposi sarcoma related to the acquired immunodeficiency syndrome (AIDS). A phase II trial with preliminary evidence of antiviral activity and low incidence of opportunistic infections.

STUDY
OBJECTIVE: To study the efficacy of high doses of beta-ser-interferon (recombinant human 17-serine beta-interferon) in patients with human immunodeficiency virus (HIV) infection and Kaposi sarcoma.
DESIGN: A nonrandomized, controlled trial of two high-dose regimens of beta-ser-interferon administered until tumor progression, toxicity, or an acquired immunodeficiency syndrome (AIDS)-defining opportunistic infection occurred.
SETTING: An AIDS treatment clinic at a tertiary care center. PATIENTS: A sequential sample of 39 patients with biopsy-proven, AIDS-related Kaposi sarcoma were enrolled during a 2-year period. Thirty-eight patients were evaluable for response. Most patients (35 of 38) had one or more of the following clinical or laboratory predictors for a poor response to interferon therapy: HIV p24 antigenemia, low CD4 cell numbers, elevated beta 2-microglobulin levels, previous opportunistic infections, or previous systemic chemotherapy.
INTERVENTIONS: Beta-ser-interferon was self-administered subcutaneously at home 5 days per week. The first 21 patients used 90 million IU/d, and the remainder used 180 million IU/d.
MEASUREMENTS AND MAIN RESULTS: Six patients (16%) had a major clinical response, and 15 (39%) had stable disease for prolonged periods. Toxicities were minimal; the major toxicity was a skin reaction at the injection site. The HIV p24 antigen level declined more than 50% in 8 of the 19 patients with initial values greater than 50 pg/mL. Antiretroviral activity and antitumor activity were seen only in patients with normal initial beta 2-microglobulin levels. Minimal changes were seen in CD4 and CD8 cell numbers. Only 1 patient had an opportunistic infection while on study, but five other patients developed infections after treatment was discontinued for an incidence of six opportunistic infections in 285 patient-observation months.
CONCLUSIONS: The high doses of interferon did not improve the major response rate in patients with poor-prognosis, AIDS-related Kaposi sarcoma. There was, however, a suggestion of antiviral activity in patients with normal beta 2-microglobulin levels and a decrease in the expected incidence of opportunistic infections.