Tenofovir not linked to bone toxicity in children followed for one year

A prospective, longitudinal, 48 month study by Italian researchers concludes that in HIV infected children, a 12 month treatment with tenofovir (TDF) was not associated with an impairment on bone mineral accrual.

Vania Giacomet and colleagues in Milan, designed their study after decreased bone porosity and osteomalacia were described in infant macaques exposed to tenofovir (TDF, Viread). Few human data were available.

13 HIV-positive children (aged ranged from 6.4 to 17.3 years) on HAART containing 3TC (lamivudine, Epivir), d4T (stavudine, Zerit) and a protease inhibitor (PI) with a mean exposure of 69 months, were switched to a regimen of 3TC, TDF and efavirenz (EFV, Sustiva).

Bone mineral density (BMD) and content (BMC) were monitored 12 months prior to the switch (T-12), at the time of the switch (T0) and 12 months after the switch (T+12). A group of 166 healthy volunteers aged from 5.7 to 19.9 years acted as a control group. Expected changes in bone mineral measurements were calculated from the control group data and were then compared to those observed in the HIV-positive children.

During both the year prior to the switch and the year using tenofovir the annual increase in spine BMC and BMD seen in the HIV-positive children was similar to those expected in the control children, regardless of the antiretroviral regimen. In the year prior to the switch the increase in total body BMC and BMD in 3TC/d4T/PI-treated children was higher than those expected in the control group.

In the following year, the increase of total body BMC and BMD in children treated with 3TC/TDF/EFV was similar to those expected in the control children. The annual changes on lumbar spine BMC and BMD, on total body BMC were similar between 3TC/d4T/PI and 3TC/TDF/EFV-treated children, while the annual change on total body BMD was higher in the 3TC/d4T/PI-treated children.

Giacomet V, Mora S, Cafarelli L et al. A 12-month treatment with tenofovir does not result in bone mineral loss in HIV-infected children. 12th CROI, Boston, 2005. Abstract 51a.