CTNPT 003: Bone and renal outcomes in tenofovir exposed infants

About The Study

This pilot study gathered data to help better understand the effects of two HIV medications (tenofovir and zidovudine) on infants’ health. Study researchers examined if tenofovir exposure during an HIV-positive mother’s pregnancy affects the bones and kidneys of her uninfected infant, and if those effects are different from infants who were exposed to zidovudine. Infants were assessed for any signs of mitochondrial toxicity and whether there is a difference in toxicity between tenofovir and zidovudine exposed infants.

About The Disease

Currently, use of tenofovir-based antiretroviral therapy regimens in pregnant women living with HIV to prevent transmission to the baby is not routinely recommended because of a lack of safety and efficacy information. However, more women are taking tenofovir-based regimens during pregnancy for different reasons (resistance, treatment of other infections, preference, etc.). Therefore, it is important to understand the effects tenofovir exposure may have on infants’ health.

Study Approach

Eligible participants were asked some general health questions about the infant’s medical history and also the mother’s medical and pregnancy history. This information included the mother’s age and race, as well as medications she was taking and blood work results. The study visits occurred when the infant was 1-month, 6-months and 18-months of age, and at the same time as regular clinic visits. At these visits, the following tests were done:

• Bone mineral density of the lumbar spine
• X-ray to assess for rickets (a disease of the bones) (at 1-month and 18-months visits only)
• The infant had blood and urine samples taken for bone, kidney, and mitochondrial testing. Some of the blood tests were the same ones that are done for a regular visit. The extra tests were done when the child’s regular blood work is being done, and a small amount of extra blood was taken. The total amount of blood drawn (for routine care and for the study) was approximately 5 mL (or 1 teaspoon).
• Growth parameters such as height and weight were recorded.

Preliminary Results

At IAS in 2019, the CTNPT 003 team reported that infants who were exposed to tenofovir appeared to have lower spinal bone mineral density at 1 month of age. But, by 6 months of age, bone mineral density was recovered, and tenofovir-exposed infants actually had a greater bone mineral density by 19 months of age. Data presented at CAHR 2015 suggested that tenofovir-exposed infants in this study did not show signs of impaired kidney function up to 18 months of age. Final results are pending for this study.