909. HIV Viral Dynamics of Lopinavir/ritonavir Monotherapy as Second-Line Treatment in a Resource-Limited Setting
Session: Poster Abstract Session: Clinical Trials
Friday, October 9, 2015
Room: Poster Hall
  • 2015.10.04 IDSA Poster.pdf (1.6 MB)
  • Background:

    The feasibility of lopinavir/ritonavir (LPV/r) monotherapy as a treatment option in patients failing first-line ART in resource-limited settings remains unclear.  Further defining viral response to protease inhibitor monotherapy remains important to help guide recommendations.


    This was  a prospective, single-arm, non-randomized, open-label, proof-of-concept study evaluating the efficacy of LPV/r mono-therapy over 48 weeks in patients with evidence of treatment failure in Jos, Nigeria.  The primary outcome of interest was sustained virologic response(VR) [HIV-1 RNA (VL) <400 copies/mL] measured at monthly intervals.


    30 patients were enrolled, with mean VL and CD4 at study entry of 135,549 copies/ml and 274 cells/mL.  28 (93%) achieved VL < 400 of any duration on LPV/r.  Mean time to VL < 400 was 7 wks, with mean duration of initial viral suppression of 10 wks.  96% experienced low-level viremia after achieving initial suppression.  73% self-reported adherence of >95% throughout the entire study period.

    In the intention to treat(ITT) analysis, only 9 (30%) met the primary outcome of sustained VR until trial completion.  The majority of study failures were due to virologic failure (2 consecutive VLs > 1000 ).  The mean VL at study failure was 151,554  and occurred at a mean of 22.7 weeks. 

    In logistic regression, baseline VL and CD4 count were not associated with treatment failure in either group, nor was historic CD4 nadir.  A detectable VL (>400) at 12 weeks had a statistically significant association with odds of either ITT failure (OR=8.75, p=0.01) or on treatment failure (OR=6.11, p=0.02), as compared to those who were undetectable.  VLs at 24 wks were also strongly predictive of treatment failure at 48 weeks(all with RNA > 400 at 24 wks failed).  Resistance was not detected in the virologic failures.


    Low-level viremia was common among all patients. LPV/r monotherapy as second-line treatment succeeded in only 30%  by ITT criteria.   VLs at 12 and 24 weeks were strongly indicative of treatment success at 48 weeks.  All patients who had a detectable VL at 24 weeks were ITT failures.  These data suggest a high adherence threshold of LPV/r monotherapy.  To use this regimen successfully, more intensive adherence interventions are likely needed..

    Cassidy Claassen, MD, MPH, Infectious Diseases, University of Maryland School of Medicine, Baltimore, MD


    C. Claassen, None

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