The ´´95% adherence rule´´ may not apply to lopinavir/ritonavir (LPV/r) based HAART regimens
Background: It is widely accepted that virologic failure is likely when adherence to highly active antiretroviral therapy (HAART) falls below 95%, although this belief has not been tested using newer agents with superior pharmacokinetic profiles.
Methods: Patients who were receiving LPV/r BID as part of their HAART regimens were enrolled into a 24-week MEMS® cap study of adherence and virologic outcomes. Adherence rate was defined as the number of bottle openings/number of doses prescribed.
Results: An interim analysis is presented for the first 53 study completers of 85 patients enrolled. The mean and median durations of MEMS monitoring were 160 and 164 days, respectively. Mean age was 45 years, 57% were male, 41% female and 2% transgender. 53% were Hispanic and 40% Black non-Hispanic. Risk factors for HIV acquisition were heterosexual contact 53%, IDU 32%, and MSM 15%. 83% of patients had CDC-defined AIDS at enrollment, and two-thirds had more than 5 years of ART experience. 1/53 was ART naïve. The mean maximum documented VL was 262,725 copies/ml. At enrollment all patients were receiving LPV/r, and 94% of patients combined this with two or more NRTIs. At enrollment 36% of patients had VL<75 and 49% had VL<400, and at 24 weeks 53% of patients had VL<75 and 78% had VL<400. The mean overall adherence rate was 73%.
[% of pts. with VL<400 at 24 wks. by adherence rate]
| Adherence rate||>95%||90-94.9%||80-89.9%||70-79.9%||50-69.9%|| <50%|
| % of pts. with VL<400 (n) at 24 weeks||70% (10)||88% (8)||100% (9)||100% (4)||55% (11)|| 73% (11)|
No association was found between 24 week VL and adherence rate (P=0.44; Spearman’s rho).
Conclusions: In this inner-city, treatment-experienced cohort with high baseline HIV-1 VL, rates of virologic failure with LPV/r based therapy were surprisingly low across the range of adherence levels studied. These results challenge the view that very high levels of adherence to all HAART regimens are necessary to avoid virologic failure.
AIDS 2006 - XVI International AIDS Conference
"J.Shuter, et al.
The ´´95% adherence rule´´ may not apply to lopinavir/ritonavir (LPV/r) based HAART regimens.
AIDS 2006 - XVI International AIDS Conference: