Safety and Effectiveness Analysis of Kivexa(®) (lamivudine/abacavir sulfate) in Human Immunodeficiency Virus Infected Korean Patients

BACKGROUND: Lamivudine and abacavir sulfate are widely used nucleoside/tide reverse transcriptase inhibitors (NRTI) backbone agents, which are recommended in major international treatment guidelines. The fixed-dose combination of lamivudine and abacavir sulfate has been developed to contribute to low pill burden of antiretroviral therapy (ART) regimen and patient adherence. A mandatory post-marketing surveillance was conducted in Korea to monitor the safety of Kivexa (lamivudine 300 mg/abacavir 600 mg). MATERIALS AND METHODS: An open label, multi-center, non-interventional post-marketing surveillance was conducted to monitor the safety of Kivexa from July 2011 to July 2017 in 23 hospitals in Korea. Subjects over 12 years old taking Kivexa per prescribing information were enrolled. The primary outcome was defined as the occurrence of any adverse events during the study period. Secondary outcomes included the occurrence of adverse drug reaction, the occurrence of serious adverse events and the effectiveness of Kivexa. RESULTS: A total of 600 patients from 23 hospitals were enrolled within the 6 years of study. The total observation period was 1,004 person-years. Three hundred and ten patients reported 674 adverse events. The incidence of upper respiratory infection (65 cases, 10.9%) was the highest, followed by diarrhea (20 cases, 3.3%), and nausea (18 cases, 3.0%). 109 subjects reported 71 events of adverse drug reactions, and the most common reaction was nausea in 2.33% of the subjects. Thirty-one subjects reported serious adverse events, none of them were considered drug related. From the total of 600 subjects, excluding 48 subjects who were ‘effectiveness unassessable’ by investigators, 552 patients were eligible for the subjective effectiveness analysis. 459 (83.2%) were evaluated as ‘improved’. Proportion of subjects whose human immunodeficiency virus-RNA is <50 copies/ml was 61.2% (309/505) at the beginning of observation and increased to 91.9% (464/505) at the end of study period. CONCLUSIONS: The post-marketing surveillance showed the safety of Kivexa in HIV-1 patients in Korea. Ischemic cardiovascular events and hypersensitivity associated with Kivexa were few. There was no significant new safety information. This data may be helpful in implementing Kivexa and lamivudine/abacavir sulfate containing drugs in Korea.