HIV PrEP study finds modest bone loss on FTC/TDF compared to cabotegravir

A two-year study comparing two forms of HIV pre-exposure prophylaxis (PrEP)—long-acting injectable cabotegravir (CAB-LA) and oral emtricitabine/tenofovir disoproxil fumarate (FTC/TDF)—found small but significant differences in bone mineral density (BMD) impact. The findings in this relatively young cohort provide a golden opportunity for us to revisit what we know about BMD in the context of PrEP, and how we can best approach conversations with our patients about their PrEP options.

Highlighted Study Population and Methods

This publication analyzed bone mineral density data from HPTN 083, a randomized, placebo-controlled study comparing CAB-LA and FTC/TDF among a racially diverse population of cisgender men and transgender women with a median age under 30.

Bone density was measured via DXA scans at three anatomic sites (lumbar spine, femoral neck, total hip). The manuscript examines data through 105 weeks of follow-up.

Key Findings

From baseline through 105 weeks:

• TDF/FTC was associated with small BMD losses at all anatomic sites: The mean change was -0.8% in lumbar spine, -1.0% in femoral neck, and -0.6% in total hip.

• CAB-LA was associated with modest BMD gains at all sites: The mean change was +1.7% in lumbar spine, +0.5% in femoral neck, and +0.8% in total hip.

• The differences between the two groups were statistically significant for lumbar spine and total hip, but narrowly missed significance for femoral neck.

• TDF/FTC users were more likely than CAB-LA users to lose >5% BMD (24.6% vs 15.2%).

Read an expert analysis from Benjamin Young, M.D., Ph.D. at TheBodyPro.