Hyperbilirubinemia Does Not Influence Persistence with Atazanavir Treatment
PHILADELPHIA, PA—Hyperbilirubinemia does not appear to influence persistence with atazanavir (ATV) in a “real-world setting,” results of a retrospective analysis reported at IDWeek 2014 have found.
To determine whether patients with HIV have poor adherence or discontinue ATV use due to hyperbilirubinemia, Lisa Rosenblatt, MD, Health Economics and Outcomes Research, Bristol-Myers Squibb, Plainsboro, NJ, and colleagues examined ATV persistence during the first year of therapy among those with and without hyperbilirubinemia which, in some patients, can lead to scleral icterus or jaundice.
Discontinuation of ATV due to hyperbilirubinemia is rare in most clinical trials, she noted; however, a recent open-label study showed a higher rate of discontinuation due to ATV-induced hyperbilirubinemia, primarily within the first 2 weeks following treatment initiation.
The study investigators “captured medical claims, pharmacy claims, and laboratory data from a large nationally representative commercial health plan from July 2003 through August 2012,” she noted. A total of 1,192 patients were included in the analysis, 131 with hyperbilirubinemia and 1,061 without hyperbilirubinemia. Mean age of the patients was 43.1 years; 82.6% were male; and 36.3% were treatment-naïve.
Hyperbilirubinemia was defined as a bilirubin laboratory test result of Grade ≥3 (>1.5 to 2.5x ULN) within the first 90 days of treatment initiation of ATV or more than 2 medical claims with a diagnosis code indicating jaundice or bilirubin excretion disorders. Non-hyperbilirubinemia was defined as Grade ≤2 in the 12-month follow-up. Persistence was defined as days on ATV until discontinuation, defined as a gap in ATV therapy of 30 days or more, or study end, whichever came first. Adherence was determined using a medication possession ratio.
In the hyperbilirubinemia cohort, there were significantly more males and those with ritonavir-boosting and fewer African Americans.
The study found no statistically significant differences between patients who experienced hyperbilirubinemia compared with those without hyperbilirubinemia “with respect to all persistence and adherence outcomes measured in this study,” Dr. Rosenblatt reported. Further, those with and without hyperbilirubinemia had a similar mean medication possession ratio, 0.93 versus 0.92 (P=0.220).
The 12-month ATV persistence rate was 259.68 days among patients with hyperbilirubinemia compared with 240.79 days among those without hyperbilirubinemia (P=0.147). The proportion of patients who discontinued from ATV was also consistent across cohorts (P=0.437).
Using multivariate analyses, the differences in both adherence and persistence remained nonsignificant after adjusting for demographic, socioeconomic status, baseline Charlson comorbidity index, and concomitant HIV medication covariates.
“Overall persistence was lower than what has been reported in clinical trials; however, results here are consistent with other claims analyses evaluating persistence of commonly prescribed antiretroviral regimens,” Dr. Rosenblatt reported.
More studies are needed comparing outcomes of ATV relative to other antiretrovirals to understand factors influencing persistence on ATV therapy.