Background
People who inject drugs (PWID) in the US have high HIV incidence and fatal overdose rates, yet uptake is low for pre-exposure prophylaxis (PrEP; 1%) and medications for opioid use disorder (MOUD; 18%). Long-acting PrEP and MOUD formulations may improve uptake and adherence.
Methods
Using the validated MYRIAD multimorbidity microsimulation model (accounting for impact of overdose and injection-related risk of HIV, hepatitis C, and bacterial infections), we simulated strategies for PWID with OUD at risk for HIV in the US (n = 1,582,233): oral PrEP (TDF/FTC [TDF]: annual drug and program costs $1,224, HIV incidence reduction 49%), long-acting injectable PrEP (cabotegravir [CAB]: $24,682, 66%; lenacapavir [LEN]: $39,490, 100%), and MOUD (HIV incidence reduction 54%) via opioid treatment program (methadone [MET]: $6,552) and office-based treatment (sublingual buprenorphine [BSL]: $1,433; extended-release injectable buprenorphine [BXR]: $26,013). We compared no PrEP/MOUD to strategies of only PrEP, only MOUD, and combinations of PrEP with MOUD. We projected 10-year outcomes for new HIV infections, deaths (from overdose, HIV, hepatitis C, and bacterial infections), life-years (LYs), costs, and incremental cost-effectiveness ratios (ICERs: difference in costs/difference in health benefits).
Results
With no PrEP/MOUD, we project 13,402 new HIV infections, 385,085 deaths, 12.18 million LYs and costs of $291 billion over 10 years. Five strategies would be cost-saving versus no PrEP/MOUD (Figure, strategies within the grey boxes): MET (saving $74 billion), MET+TDF ($72 billion), MET+CAB ($7 billion), BSL ($60 billion), BSL+TDF ($57 billion). Two strategies fall on the cost-effectiveness frontier when comparing LYs (Panel A): MET (12.62 million LYs, $217 billion) and MET+TDF (ICER $361,577/LY versus MET, exceeding a common cost-effectiveness threshold of $100,000/LY). Three strategies fall on the cost-effectiveness frontier when comparing averted HIV infections (Panel B): MET (2,497 infections averted versus no PrEP/no MOUD), MET+TDF (ICER $2,168,406/additional averted infection), and MET+LEN ($86,963,411/additional averted infection).
Conclusions
Among PWID with OUD at risk for HIV, methadone, methadone with TDF/FTC or cabotegravir, and sublingual buprenorphine with or without TDF/FTC would gain life-years, avert HIV infections, and save money. Additional long-acting injectable formulations can avert additional HIV infections but may not be cost-effective at current drug costs.