title: Long-term treatment outcomes of ritonavir-boosted lopinavir monotherapy among HIV-infected patients who experienced NRTI and NNRTI failure.
abstract: BACKGROUND
  We continue the previously described prospective cohort study of ritonovir-boosted lopinavir (LPV/r) monotherapy for second-line therapy in HIV-infected patients with prior failure and extensive resistance to nucleoside reverse transcriptase inhibitors (NRTIs) and non-nucleoside reverse transcriptase inhibitors (NNRTIs), with the objective being to determine the three-year treatment responses.
  
  
  RESULTS
  There were 40 patients with a mean ± SD age of 37 ± 8 years. Median (IQR) baseline CD4 was 123 (37-245) cells/mm3 and median (IQR) HIV-1 RNA was 55,800 (9,670-100,000) copies/mL. All patients received twice daily LPV/r 400/100 mg and recycled lamivudine 150 mg. By intend-to-treat analysis at 144 weeks, 26 (65%) and 22 (56%) patients achieved HIV-1 RNA at < 400 and < 50 copies/mL, respectively. In as-treated analysis, the corresponding rates were 26 of 28 (93%) and 22 of 28 (78%), respectively. Low-level viral rebound (HIV-1 RNA 50-400 copies/mL) was found in 6 (15%), 6 (15%), and 4 (10%) patients at week 48, 96 and week 144, respectively. Medians CD4 at week 48, 96, and 144 were 351, 481, and 584 cells/mm3 and significantly changed from baseline (all, P < 0.05). There were increments of mean triglycerides at 48 weeks and 144 weeks from baseline (P < 0.05). No major protease resistance-associated mutations emerged after virologic failure.
  
  
  CONCLUSIONS
  LPV/r monotherapy with recycled lamivudine can maintain long-term virologic suppression in a relatively small proportion of patients failing NNRTI-based regimen and having limit option for active NRTI. More antiretroviral classes are needed be accessible in resource-limited countries.
authors.affiliation: Bamrasnaradura Infectious Diseases Institute, Ministry of Public Health, Nonthaburi 11000, Thailand. drweerawat@hotmail.com.
authors.forename: Weerawat
authors.initials: W
authors.lastname: Manosuthi
authors.forename: Supeda
authors.initials: S
authors.lastname: Thongyen
authors.forename: Samruay
authors.initials: S
authors.lastname: Nilkamhang
authors.forename: Sukanya
authors.initials: S
authors.lastname: Manosuthi
authors.forename: Somnuek
authors.initials: S
authors.lastname: Sungkanuparph