Lopinavir/r monotherapy for PMTCT

In an oral late breaker, Roland Tubiana presented findings from a French multisite PMTCT study – PRIMEVA (NCT00424814) designed to evaluate the use of lopinavir/r (LPV/r) monotherapy in pregnancy for women not needing treatment for their own health.

This was an open label, phase II/III trial. Untreated women with CD4 >350 cells/mm3 and viral load <30,000 copies/mL were randomised 2:1 to receive either LPV/r monotherapy (n=69) or LPV/r + AZT + 3TC (n=36), from 26 weeks gestation until delivery.

The primary endpoint of the trial was >75% women with viral load <200 copies/mL at week 8 of treatment. Secondary endpoints included viral load at delivery and comparative analysis of safety outcomes during pregnancy and until 24 months in children.

The baseline characteristics were similar between arms; women had a median CD4 count of 525 cells/mm3 and viral load of 2952 copies/mL.

Intent-to-treat analysis of the monotherapy arm revealed a viral load <200 copies/mL at week 8 in 61/69 women (88.4%, 95% CI 78.4-94.9). This was similar to that observed in the control arm (94.4%, 95% CI 81.3-99.3) p=0.18.

The proportions of women with viral load <200 copies/mL at delivery was similar between the LPV/r and control arms, 91.3% (95% CI, 82.0-96.7) vs 97.2% (95% CI, 85.5-99.9), p=0.41. But when the investigators looked at viral load <50 copies/mL at the same time point, a greater proportion of women in the control arm achieved this, 79.7% (95% CI 63.3-88.4) vs 97.2% 985.5-99.9) in the LPV/r and control arms respectively, p=0.01.

Similar proportions of cesarean section delivery (49.5%) and pre-term delivery (10.5%) were observed in both arms. Changes of ART due to tolerability were significantly less frequent the monotherapy arm compared to control, respectively 1.4% vs 11.1%, p=0.046.

There was one case of transmission in the control and none in the monotherapy arm.

Tubiana R et al. LPV/r monotherapy during pregnancy for PMTCT of HIV-1: The PRIMEVA/ANRS 135 randomised Trial, pregnancy outcomes. 18th CROI. Boston. February 2011. Oral abstract 125LB.
http://www.retroconference.org/2011/Abstracts/42568.htm