Compatibility of Direct Acting Antivirals and Antiretroviral Therapy in HCV/HIV Patients
SAN DIEGO, CA— Efavirenz-, atazanavir + ritonavir-, and raltegravir-containing regimens are compatible for use with direct acting antivirals, stated Sonia Vibhakar, PharmD, from The Ruth M. Rothstein CORE Center, Chicago, IL, and colleagues, at IDWeek 2012.
Two directly acting antivirals were approved in 2011 for HCV treatment. However, significant drug-drug interactions exist between direct acting antivirals for HCV and antiretroviral therapy for HIV.
Dr. Vibhakar and colleagues aimed to describe the epidemiology of HIV+/HCV+ patients with advanced liver fibrosis and determine the proportion of patients eligible for HCV treatment with direct acting antivirals based on compatible highly active antiretroviral treatment (HAART). They conducted a chart review of all HIV+/HCV+ patients with more than one visit in 2011.
FIB-4 (calculated as age x AST/platelets x square root of ALT), a non-invasive marker for assessing liver fibrosis, with scores >3.25 (82% positive predictive value and 98% specificity) for advanced fibrosis was used to select patients with advanced liver disease. Of the 4,756 HIV+ patients seen in 2010, 841 were HCV+; of these, approximately 17% had advanced fibrosis and 139 with FIB-4 scores >3.25 were analyzed.
The majority of HIV+/HCV+ co-infected patients with advanced fibrosis were older and non-Hispanic black; only 12% had received treatment for HCV. Median age was 57 years, and 73% were male. Median CD4 was 278 and 65% had HIV RNA <75copies/mL, which is lower than the overall CORE population (median CD4 401, 73% HIV RNA <75copies/mL).
The majority (94%) of patients were on HAART; 78 (56%) were on “compatible” HAART. The average HCV viral load was 1.99 log and 17 (12) had previously been treated for HCV. Based on previous HIV genotypic resistance test (GART), available for 54 patients, most of those not on a “compatible” regimen could potentially switch to one. A total of 13 patients were on statin drugs and 26 were on drugs for erectile dysfunction, both classes of which have major drug interactions with the directly acting antivirals.
Dr. Vibhakar noted that nearly half the patients were on “compatible” HAART regimens, and the majority of those that were not could be switched to one. In addition, the majority of patients with advanced fibrosis had not received HCV treatment for reasons other than drug-drug interactions with the directly acting antivirals, which included active substance abuse, poor adherence, and uncontrolled psychiatric illness.
“Our findings underscore the importance of aggressively addressing many of these issues before the impact of these new HCV treatments can be felt in many clinics. These issues are especially important in patients with advanced fibrosis who are at the highest risk of morbidity and mortality,” she concluded.