Pharmacokinetics and 48-week safety and efficacy of generic lopinavir/ritonavir in Thai HIV-infected patients.

Background: Generic products reduce the costs of HIV treatment. Few generic second-line antiretroviral products are available. We assessed pharmacokinetics, safety and efficacy of generic lopinavir/ritonavir (LPV/r) produced by the Government Pharmaceutical Organization (GPO) of Thailand in Thai HIV-infected adults.

Methods: This was a single-arm prospective study. Patients with plasma HIV-1 RNA<50 copies/ml for ≥24 weeks, who were protease inhibitor (PI)-naive or experienced, were eligible. Patients started generic LPV/r tablets, 400/100 mg twice daily. At week 4, therapeutic drug monitoring was performed and analysed by validated HPLC. In patients using Kaletra(®) (Abbott Laboratories, North Chicago, IL, USA) soft gel capsules (SGC) or generic LPV/r tablets produced by Mylan (Canonsburg, PA, USA; formerly Matrix, Hyderabad, India) prior to study entry, we compared the plasma minimum concentrations (Cmin) of the different formulations. Plasma HIV-1 RNA and safety were assessed until week 48.

Results: A total of 70 patients (32 males) were enrolled. Mean (sd) age was 40.7 (7.9) years and mean (sd) body weight was 60.3 (9.0) kg. Before study entry, all patients were virologically suppressed using a PI-based regimen; 62 (88.6%) were using LPV/r (Kaletra(®) SGC n=22 and Mylan generic tablets n=40). Mean (sd) Cmin of GPO lopinavir and GPO ritonavir at week 4 were 7.1 (2.9) mg/l and 0.39 (0.21) mg/l, respectively, and not significantly different from the Cmin when taking Kaletra(®) SGC or Mylan generic tablets. After 48 weeks, 95.6% of patients maintained plasma HIV-1 RNA<50 copies/ml. Four grade 3 and no grade 4 adverse events were reported.

Conclusions: Generic LPV/r showed adequate levels, good tolerability and excellent 48-week efficacy.