Modeling the Long-Term Bone Health Impact of TDF/FTC PrEP in Adolescent MSM
Author(s)
Turgay Ayer, PhD1, Mert Edali, PhD1, Oya Hoban, BSc2, Halley Wasserman, MD3, Natalya Danchenko, PhD4, Jeremy Fraysse, MS5, Sarah-Jane Anderson, PhD6, Heidi Swygard, MD5.
1Value Analytics Labs, Boston, MA, USA, 2Value Analytics Labs, Wilmington, MA, USA, 3Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA, 4ViiV Healthcare, Paris, France, 5ViiV Healthcare, Research Triangle Park, NC, USA, 6GSK, London, United Kingdom.
1Value Analytics Labs, Boston, MA, USA, 2Value Analytics Labs, Wilmington, MA, USA, 3Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA, 4ViiV Healthcare, Paris, France, 5ViiV Healthcare, Research Triangle Park, NC, USA, 6GSK, London, United Kingdom.
OBJECTIVES: Adolescent MSM may have significant risk of HIV acquisition and need for PrEP (Pre-Exposure Prophylaxis). In the presence of high adherence, TDF/FTC PrEP is effective at preventing HIV acquisition but is known to decrease Bone Mineral Density (BMD). TDF/FTC exposure in adolescent MSM may have important consequences for Peak Bone Mass (PBM). PBM is the maximum bone strength an individual can achieve and strongly predicts osteoporosis risk in later life. While the short-term impact of TDF/FTC PrEP on bone health has been observed in clinical trials, modelling is required to project long-term effects.
METHODS: The model simulated a cohort of 50,000 young MSM, across various TDF/FTC PrEP use scenarios in adolescence (including durations of up to 3 years of continuous or intermittent use). The natural history of BMD without TDF/FTC PrEP was derived from NHANES data, while BMD changes with TDF/FTC were informed by clinical trials (ATN 110 and ATN 113). Total hip BMD trajectories were tracked between ages 15 to 70, with t-scores used to assess the prevalence of osteoporosis and osteopenia.
RESULTS: Compared to the modelled scenario with no TDF/FTC PrEP use in adolescence, daily dosing led to lower PBM and higher osteoporosis prevalence later in life (e.g., 3 years of continuous use led to a 27% increase in osteoporosis prevalence by age 70 in the modelled population). Intermittent use did not entirely prevent long-term bone loss. Daily dosing of TDF/FTC PrEP significantly reduced modelled HIV acquisitions in this high-risk population.
CONCLUSIONS: This analysis underscores the need for effective PrEP options for adolescent MSM while considering long-term BMD consequences. This suggests the need for complementary interventions to minimize the impact on BMD or alternative PrEP options (including injectable CAB-LA PrEP with no observed impact on BMD from available short-term study data).
METHODS: The model simulated a cohort of 50,000 young MSM, across various TDF/FTC PrEP use scenarios in adolescence (including durations of up to 3 years of continuous or intermittent use). The natural history of BMD without TDF/FTC PrEP was derived from NHANES data, while BMD changes with TDF/FTC were informed by clinical trials (ATN 110 and ATN 113). Total hip BMD trajectories were tracked between ages 15 to 70, with t-scores used to assess the prevalence of osteoporosis and osteopenia.
RESULTS: Compared to the modelled scenario with no TDF/FTC PrEP use in adolescence, daily dosing led to lower PBM and higher osteoporosis prevalence later in life (e.g., 3 years of continuous use led to a 27% increase in osteoporosis prevalence by age 70 in the modelled population). Intermittent use did not entirely prevent long-term bone loss. Daily dosing of TDF/FTC PrEP significantly reduced modelled HIV acquisitions in this high-risk population.
CONCLUSIONS: This analysis underscores the need for effective PrEP options for adolescent MSM while considering long-term BMD consequences. This suggests the need for complementary interventions to minimize the impact on BMD or alternative PrEP options (including injectable CAB-LA PrEP with no observed impact on BMD from available short-term study data).
Conference/Value in Health Info
2025-11, ISPOR Europe 2025, Glasgow, Scotland
Value in Health, Volume 28, Issue S2
Code
EPH162
Topic
Economic Evaluation, Epidemiology & Public Health
Disease
Infectious Disease (non-vaccine), Musculoskeletal Disorders (Arthritis, Bone Disorders, Osteoporosis, Other Musculoskeletal), Reproductive & Sexual Health