Results from a clinical trial funded by the National Institutes of Health (NIH) in five major United States cities show that delivering integrated HIV and substance use disorder (SUD) services using peer navigation in mobile medical units reduced all-cause deaths by 71% compared to participants who received peer navigation to community-based services alone. While scientists found no difference in the use of daily, oral preexposure prophylaxis (PrEP) and medication for opioid use disorder (MOUD) between the groups, the secondary outcome of reduced mortality was significant.
"Injection drug use is an important contributor to HIV in the U. S. that also increases risk for other serious infectious diseases," said Nora D. Volkow, M.D., director of NIH's National Institute on Drug Abuse (NIDA), which funded the study. "Although we have effective interventions for this population, there are significant barriers to their accessibility and use. Nonetheless, these findings suggest that delivering low threshold services through mobile units could save lives."
The trial, known as the HIV Prevention Trials Network Study 094 (HPTN 094), enrolled 409 adults without HIV, who injected drugs, had opioid use disorder, who were not taking MOUD at enrollment, and who were willing to consider MOUD. The trial took place in Houston, Los Angeles, New York City, Philadelphia, and Washington, D.C. One group received 26 weeks of peer navigation plus integrated PrEP, MOUD, and limited clinical and supportive services delivered on a mobile unit. The other group received 26 weeks of peer navigation services that linked participants to available non-mobile community services.
While verified PrEP use for both groups was low at 26 weeks, it was favorable compared to self-reported use among people who inject drugs. Additionally, although there was no difference in MOUD use between study arms, 14% of people used MOUD at 26 and 52 weeks, a clinically meaningful level considering none were on MOUD at study start.
"People who inject drugs often face fragmented systems, unstable housing, stigma, and other barriers that make sustained care difficult," said Nabila El-Bassel, Ph.D., the Willma and Albert Musher Professor of Social Work at Columbia University and study co-chair. "Our findings show why we must continue developing models that meet people where they are and connect HIV prevention, addiction treatment, and supportive care in ways that are accessible and responsive to their lives."
According to researchers, the relatively low use of oral PrEP, even in the context of structured peer navigation, underscores that PrEP uptake has major challenges for acceptance among people who inject drugs and points to the importance of evaluating long-acting PrEP formulations within this population.
Steven Shoptaw, Ph.D., the George F. Kneller Endowed Chair in Family Medicine, and vice chair for Research in the UCLA Department of Family Medicine, also served as study co-chair.
The HIV Prevention Trials Network is sponsored by NIH's National Institute of Allergy and Infectious Diseases and HPTN 094 was funded by NIDA. Overall support for the trial was through awards UM1AI068619, UM1AI068617, and UM1AI068613.
Reference: S Shoptaw, N El-Bassel, et al. Mobile Units for Integrated Addiction and Prevention Services for People Who Inject Drugs: The HPTN 094 Randomized Clinical Trial. JAMA Psychiatry. 2026. DOI: 10.1001/jamapsychiatry.2026.3644.
