Pharmacokinetics of Saquinavir-SGC in HIV-Infected Pregnant Women

Authors:
  • CZCarmen Zorrilla
    Carmen Zorrilla
  • RDRussell Van Dyke
    Russell Van Dyke
  • ABArlene Bardeguez
    Arlene Bardeguez
  • ESElizabeth Smith
    Elizabeth Smith
  • MHMichael Hughes
    Michael Hughes
  • SHSharon Huang
    Sharon Huang
  • JPJane Pitt
    Jane Pitt
  • HWHeather Watts
    Heather Watts
  • PTPediatric AIDS Clinical Trials Group 386 Protocol Team
    Pediatric AIDS Clinical Trials Group 386 Protocol Team

Abstract
Purpose: To evaluate saquinavir (SQV) pharmacokinetics, tolerance, and safety in 10 HIV-infected pregnant women between 14-32 weeks gestation. Method: This was a phase I, prospective, area-under-the-curve (AUC) targeted study. Antepartum treatment consisted of SQV 1200 mg tid, lamivudine 150 mg bid, and zidovudine 200 mg tid. The SQV targeted exposure was an 8-hour AUC (AUC8) of 3000 ng · h/mL; the study was to be halted if the first 4 participants did not achieve this AUC8. Cord blood and plasma samples were collected in neonates at birth. Results: Four women completed the SQV pharmacokinetic assessments. Exposure in all 4 patients was below the target AUC8. Median (range) AUC8 and trough (C8H) were 1672 (738-2614) ng · h/mL and 60 (max was 599 (177–953) ng/mL. Cord and neonate plasma concentrations were mostly undetectable; 1 of 5 infants was HIV-infected at 24 weeks. Conclusion: These data suggest highly variable SQV pharmacokinetics in pregnant women, and exposure at 1200 mg tid may not be adequate for longer term therapy; both the AUC8 and C8H were considerably below average. Because ritonavir has been shown to significantly increase SQV concentrations, this combination should be further explored in this population.