Long-Acting Cabotegravir Appears Safe in Pregnancy

HIV pre-exposure prophylaxis (PrEP) with long-acting injectable cabotegravir (CAB-LA; Apretude) appeared safe during pregnancy among cisgender women, according to an analysis of the HPTN 084 open-label extension trial.

Composite poor pregnancy outcomes were reported in 33% of pregnancies with active CAB-LA use, 38% with prior CAB-LA use, and 27% with no previous or active CAB-LA use, respectively, Sinead Delany-Moretlwe, MBBCh, PhD, of the University of the Witwatersrand in Johannesburg, reported at the International AIDS Conference in Munich.

Spontaneous abortion at less than 20 weeks’ gestation drove rates of poor pregnancy outcomes, a composite endpoint that also included intrauterine fetal death or stillbirth at 20 weeks or greater, premature birth, and small for gestational age.

“Cisgender women experience biological changes and social dynamics that can increase their likelihood of acquiring HIV during pregnancy and the postnatal period, and we need to offer them evidence-based options when they may need them most,” said Jeanne Marrazzo, MD, MPH, director of the National Institute of Allergy and Infectious Diseases (NIAID), in a press release. “These data provide reassurance about long-acting injectable cabotegravir for HIV prevention during pregnancy.”

The majority of pregnancies — about 44-67% across the three groups — resulted in live births, 1-7% of pregnancies resulted in preterm births, and less than 4% of pregnancies ended in stillbirth.

Spontaneous abortion occurred in 20% of those with active CAB-LA use, 31% with prior CAB-LA use, and 13% without any CAB-LA use. All fell within the expected background rate.

“It’s important to interpret the spontaneous abortion data with caution, given the non-legal status of termination of pregnancy in many of the HPTN 084 countries,” Delany-Moretlwe pointed out.

The incidence of pregnancy-related maternal adverse events that were Grade 2 or higher was also similar across the three groups and on par with background rates, Delany-Moretlwe said. The incidence per 100 person-years was 38 with active CAB-LA use during pregnancy, 47 with prior CAB-LA use, and 31 with no previous or current use of CAB-LA. Although the incidence rates were highest in the active CAB-LA group, confidence intervals overlapped with the other two groups, she pointed out. Gestational hypertension, hyperemesis gravidarum, and afterbirth pain were the most frequent Grade 2 or higher pregnancy-related events.

Among mothers actively receiving CAB-LA, 18% underwent a cesarean section — about the same as those with prior or no CAB-LA exposure. Delivery complications occurred in 8% in the active CAB-LA group, 15% of those with prior CAB exposure, and 6% of those with no CAB-LA exposure.

There were no maternal deaths or HIV infections observed during pregnancy in any of the exposure groups, Delany-Moretlwe noted.

With respect to infant outcomes, growth parameter z-scores were similar across the three groups, as were median gestational age at delivery (37-39 weeks), median birth weight (3 kg), and size for gestational age.

“Ten percent or less of infants were assessed as small for gestational age, which is in fact lower than previously reported,” Delany-Moretlwe pointed out.

Of four neonatal deaths that occurred during the study, all occurred in pregnancies with active CAB-LA use. One of the deaths involved a major congenital anomaly and the other three deaths were due to respiratory distress. However, all deaths were considered unrelated to PrEP.

The prevalence of neonatal deaths in the study “is consistent with background rates of neonatal death, which can range from 1-4% in similar populations,” Delany-Moretlwe told attendees.

The primary HPTN 084 trial demonstrated that CAB-LA significantly reduced HIV acquisition compared to daily oral tenofovir/emtricitabine (TDF/FTC, Truvada) in women. During the randomized period of the trial, participants were required to use a long-acting reversible contraceptive and those with a positive pregnancy test had CAB-LA held at the time.

However, starting in 2022 when participants in HPTN 084 were offered the choice of CAB-LA or TDF/FTC as PrEP in the open-label extension of the trial, contraceptive restrictions were removed. Included in this safety analysis were 212 pregnancies with active CAB-LA use, 68 with prior CAB-LA use, and 45 pregnancies with no CAB-LA use.

Among these 325 pregnancies, the median age at the start of pregnancy was about 28 years, while the median number of previous pregnancies was one to two across groups. Of women who had been previously pregnant, 25% reported poor previous pregnancy outcomes. Most had a history of sexually transmitted infections prior to pregnancy.

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