Safety and Efficacy of Ziagen (Abacavir Sulfate) in HIV-Infected Korean Patients

Abacavir is a widely-used nucleoside reverse transcriptase inhibitor for the treatment of human immunodeficiency virus (HIV) infection. Mandatory postmarketing surveillance was conducted in Korea to monitor the safety and evaluate the effectiveness of Ziagen® (abacavir sulfate 300 mg; ViiV Healthcare, Middlesex, UK). An open-label, multi-center, non-interventional postmarketing surveillance study was conducted from June 2010 to June 2016 to monitor the safety and effectiveness of Ziagen across 12 hospitals in Korea. Subjects older than 18 years taking Ziagen according to prescribing information were enrolled. The primary outcome was defined as the occurrence of any adverse events after Ziagen administration. Secondary outcomes included the occurrence of adverse drug reactions, occurrence of serious adverse events, and effectiveness of Ziagen administration. A total of 669 patients were enrolled in this study, with a total observation period of 1047.8 person-years. Of these, 90.7% of patients were male. The mean age of patients was 45.8±11.9 years. One-hundred ninety-six (29.3%) patients reported 315 adverse events, and four patients reported seven serious adverse events, without any fatal events. There was one potential case of an abacavir hypersensitivity reaction. Among the 97 adverse drug reactions that were reported from 75 patients, the most frequent adverse drug reactions included diarrhea (12 events), dyspepsia (10 events), and rash (9 events). No ischemic heart disease was observed. In the effectiveness analysis, 91% of patients achieved HIV-1 RNA under 50 copies/mL after 24 months of observation with abacavir administration. Our data showed the safety and effectiveness of Ziagen in a real-world setting. During the study period, Ziagen was well-tolerated, with one incident of a clinically suspected abacavir hypersensitivity reaction. The postmarketing surveillance of Ziagen did not highlight any new safety information. These data may be helpful in understanding abacavir and the HIV treatment practices in Korea.