Tivicay Side Effects May Increase Neural Tube Birth Defect Risks, Researchers Warn

New research suggests that side effects of Tivicay treatment for HIV-positive pregnant women may increase their risk of having a child with neural tube defects. 

According to preliminary findings of a study presented at the International AIDS Conference and published in an editorial in the New England Journal of Medicine on July 24, researchers indicate that when compared to other antiretrovirals, women were six to nine times more likely to have an infant with neural tube defects following pregnancy use of Tivicay, a dolutegravir-based antiretroviral.

Antiretrovirals are drugs given in combination to help slow the rate at which HIV spreads. They are used to help prevent the disease and help to treat it once a person is infected. Tivicay has shown to be quite effective and more widely tolerated, which is why the World Health Organization recommends its use. However, researchers are now questioning whether it is contributing to neural tube birth defects, which can cause large holes in the spine or prevent the top of the skull from forming properly.

Researchers from the Botswana Harvard AIDS Institute Partnership analyzed data for more than 89,000 births from pregnant women, both HIV positive and non-infected, in eight of the largest maternity wards in Botswana. This includes roughly 45% of total births in the country.

If a neural tube defect was suspected in a mother, doctors contacted researchers to confirm the defect by photographing the abnormality and conferring with experts from the U.S. A total of 86 infants with neural-tube defects were recorded overall.

While the prevalence of defects wasn’t extremely high, it was enough to indicate a potential problem, the researchers indicated. The study is ongoing and full data will be published once the study is complete.

In May 2016, Botswana changed its preferred antiretroviral therapy for all adults from Sustiva, an efavirenz based antiretroviral, to Tivicay, a dolutegravir antiretroviral. This allowed researchers to begin comparing the efficacy of Tivicay, as well as its impact on a fetus.

In April 2018, researchers detected more cases of neural-tube defects among infants born to women who started treatment with Tivicay before conception.

According to the findings, while only four of the 426 HIV-positive women taking Tivicay since before conception gave birth to children with neural tube defects, representing 0.94%, that is nine times higher than the rate of neural tube defect births among women who did not take the drug.

Among 2,800 infants born to women who started Tivicay after the women was already pregnant, there were no cases of neural tube defects.

Researchers updated the prevalence with new data from the earlier midpoint of April 2018. The new data indicated the prevalence of neural tube defects was roughly 0.67% among women who took Tivicay from conception.

While the occurrence is lower, it is still six times higher than among the other groups of women taking other antiretrovirals.

If fewer cases of birth defects are seen during the latter half of the study, the risk decreases significantly, becoming similar to the risk seen with other retrovirals. The next analysis of the data will be conducted in March 2019.

“We found a potential early signal for an increased prevalence of neural-tube defects in association with dolutegravir-based antiretroviral therapy from the time of conception,” the researchers wrote. “Our study is ongoing, and more data are needed to confirm or refute this signal, given the small number of events and the small difference in prevalence.”