title: Cost-efficacy analysis of the MONET trial using UK antiretroviral drug prices.
abstract: BACKGROUND
  In virologically suppressed patients, switching to darunavir/ritonavir (DRV/r) monotherapy maintains HIV RNA suppression, and could also lower treatment costs.
  
  
  OBJECTIVE
  The purpose of this analysis was to calculate the potential cost savings from the use of DRV/r monotherapy in the UK.
  
  
  METHODS
  In the MONET trial, 256 patients with HIV RNA < 50 copies/mL on current highly active antiretroviral therapy (HAART) for over 24 weeks (non-nucleoside reverse-transcriptase inhibitor [NNRTI] based [43%] or protease inhibitor [PI] based [57%]), switched to DRV/r 800/100 mg once daily, either as monotherapy (n = 127) or with two NRTIs (n = 129). The UK costs per patient with HIV RNA < 50 copies/mL at week 48 (responders) were calculated using a 'switch included' analysis to account for additional antiretrovirals taken after initial treatment failure. By this analysis, efficacy was 93.5% versus 95.1% in the DRV/r monotherapy and triple therapy arms, respectively. British National Formulary 2009 values were used.
  
  
  RESULTS
  Before the trial, the mean annual cost of antiretrovirals was £6906 for patients receiving NNRTI-based HAART, and £8348 for patients receiving PI-based HAART. During the MONET trial, the mean annual per-patient cost of antiretrovirals was £8642 in the triple therapy arm, of which 55% was from NRTIs and 45% from PIs. The mean per-patient cost in the monotherapy arm was £4126, a saving of 52% versus triple therapy. The mean cost per responder was £9085 in the triple therapy arm versus £4413 in the DRV/r monotherapy arm.
  
  
  CONCLUSIONS
  Based on the MONET results, the lower cost of DRV/r monotherapy versus triple therapy in the UK would allow more patients to be treated for fixed budgets, while maintaining HIV RNA suppression at < 50 copies/mL. If all patients meeting the inclusion criteria of the MONET trial in the UK were switched to DRV/r monotherapy, there is the potential to save up to £60 million in antiretroviral drug costs from the UK NHS budget.
authors.affiliation: Chelsea and Westminster Hospital, London, UK.
authors.forename: Brian
authors.initials: B
authors.lastname: Gazzard
authors.forename: Andrew
authors.initials: A
authors.lastname: Hill
authors.forename: Anne
authors.initials: A
authors.lastname: Anceau
mesh_terms: D000328:Adult; D023241:Antiretroviral Therapy, Highly Active / Q000191:economics*; D000998:Antiviral Agents / Q000191:economics / Q000627:therapeutic use; D003365:Costs and Cost Analysis / Q000706:statistics & numerical data; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000191:economics*; D017048:Health Care Costs / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019438:Ritonavir / Q000627:therapeutic use; D006113:United Kingdom
chemical_list: D000998:Antiviral Agents; D019438:Ritonavir