Table 1.
Input parameters for a cost-effectiveness analysis of CAB-LA vs. generic F/TDF and branded F/TAF for HIV PrEP among MSM/TGW in the US
| Parameter | Value | Range | Source |
|---|---|---|---|
|
| |||
| Initial MSM/TGW cohort characteristics | |||
| Age, mean (years) | 30.1 | 20–40 | (1) |
| Sex assigned at birth, male (%) | 100 | (1) | |
| MSM/TGW at VHR, without HIV (n) * | 476,700 | Der. From (11,12) | |
| MSM/TGW at HR, without HIV (n) | 1,906,800 | Der. From (11,12) | |
| Primary transmissions, annual (n) | |||
| Attributable to MSM/TGW at VHR | 17,770 | 1,970–19,740 | Der. From (12) |
| Attributable to MSM/TGW at HR | 19,740 | 2,800–28,200 | Der. From (12) |
| PrEP program characteristics | |||
| Initial PrEP uptake (%) | 100 | 15–100 | Modeled population |
| Estimated HIV incidence, VHR (rate/100PY) | (1) | ||
| No PrEP | 5.32 | 2.66–10.64 | |
| Generic F/TDF and branded F/TAF | 1.33 | 0.67–2.66 | |
| CAB-LA | 0.26 | 0.13–0.52 | |
| Estimated HIV incidence, HR (rate/100PY) | Der. from (1,11,12) | ||
| No PrEP | 1.54 | 0.77–3.08 | |
| Generic F/TDF and branded F/TAF | 0.39 | 0.19–0.78 | |
| CAB-LA | 0.08 | 0.04–0.16 | |
| PrEP retention (annual probability) † # | |||
| Generic F/TDF and branded F/TAF | 0.809 | (14) | |
| CAB-LA | 0.809 | 0.809–0.997 | (14) |
| PrEP program characteristics, continued | |||
| Quality-of-life on F/TDF, monthly | |||
| End-stage renal disease, lifetime | 0.53 | (17) | |
| Fracture, 12 months | 0.7 | (18) | |
| PrEP costs ($) ‡ | |||
| Generic F/TDF, annual § | 790 | ||
| Program | 430 | (25,26) | |
| Drug | 360 | Der. from (23) | |
| Branded F/TAF, annual § | 17,230 | ||
| Program | 430 | (25,26) | |
| Drug | 16,800 | Der. from (23) | |
| CAB-LA, annual || | 750 + drug price | 3,050–26,650 | |
| Program | 750 | (25,26) | |
| Drug | -- | 2,300–25,850 | |
| Characteristics of those acquiring HIV | |||
| Mean CD4 at infection (cells/µL) | 667 | (44) | |
| Quality-of-life, HIV-related | |||
| Range by CD4 count | 0.83–0.87 | (45) | |
| Opportunistic infection | 0.69–1 | (46) | |
| Upon incident HIV infection, baseline ART adherence and virologic suppression | |||
| Adherence to ART ≥90% (% of cohort) | 71 | 50–100 | (47) |
| Upon incident HIV infection, baseline ART adherence and virologic suppression, continued | |||
| Integrase inhibitor-based ART efficacy (%) ¶ | 93.0 | 85.8–100 | (19,43) |
| Late virologic failure, range by adherence level (annual probability) # | 0.0012–1 | 0.0011–1 | (48,49) |
| Retention in HIV treatment | |||
| Loss to HIV care, range by adherence level (annual probability) # | 0.0012–0.57 | 0.0012–1 | (50) |
| Return to HIV care (annual probability) # | 0.999 | 0.968–1 | (51) |
| HIV-related costs ($) ‡ | |||
| Routine care costs, range by CD4 count and ART status, annual | 3,280–32,580 | 1,640–65,510 | (29–31) |
| ART, annual | 31,560–68,680 | 15,780–137,360 | (22,31) |
ART, antiretroviral therapy; CAB-LA, long-acting injectable cabotegravir; Der., derived; F/TAF, emtricitabine/tenofovir alafenamide fumarate; F/TDF, emtricitabine/tenofovir disoproxil fumarate; HIV, human immunodeficiency virus; HR, high risk for HIV; MSM, men who have sex with men; PY, person-year; PrEP, pre-exposure prophylaxis; TGW, transgender women; VHR, very high risk for HIV.
The MSM/TGW at VHR population is a subset of the MSM/TGW at HR population.
Corresponds to 28% of the initial modeled cohort retained in a PrEP program at 6 years (sensitivity analysis range of 14–98% retention at 6 years).
Costs adjusted to 2020 US dollars.
Annual program costs for generic F/TDF or branded F/TAF: level 3–4 visit ($104/visit) 4x/year (25), HIV testing 4x/year (antigen/antibody screen and additional reactive test: $40/test and $80/test (27,28)), labs including serum creatinine and urinalysis 2x/year (total $15/year) (26) and drug cost.
Annual program costs for CAB-LA: level 3–4 visit ($104) 6x/year (25), HIV testing 6x/year (antigen/antibody screen and additional reactive test: $40/test and $80/test (27,28)), labs including serum creatinine and liver function panel 2x/year (total $27/year) (26), $16/injection administration fee 6x/year (25), and drug price.
Among individuals with ≥90% adherence to an integrase-based ART regimen, 93% achieved viral suppression (VL <50 copies/mL at 48 weeks). Additional input parameters for different adherence levels may be found in Appendix Table 2.
Monthly probabilities were used in the model.
Additional details of model input parameters and derivations may be found in Appendix Tables 1 and 2 and Appendix Methods.