have shown that treatment of PWID is cost-effective despite the inclusion of reinfection and lower compliance for current and former PWID, thus providing strong evidence supporting the scale-up of treatment to these groups. However, the likely reason why Visconti et al. find that treating PWID
is less cost-effective than treating ex- or non-injectors is because reinfection Smoothened inhibitor has been included but the prevention benefit of treating PWID has been ignored. Removing chronically infected PWID averts secondary infections that those PWID may have caused and also reduces HCV chronic prevalence in the population. Indeed, treating PWID may be more cost-effective than treating former or non-injectors because of the substantial benefits achieved through averting secondary infections, despite the risk of reinfection or lower SVR rates among PWID. The result of omitting these transmission dynamics is that Visconti et al.’s model might give a misleading picture. Based on their model, non-injectors and ex-injectors would be preferentially treated rather than PWID—whereas the reverse may have been found if the model had been dynamic and allowed for any potential prevention benefit. Additionally, XL184 in vitro their model indicates early treatment with protease inhibitors is only cost-effective for non-PWID; however, inclusion of the prevention benefit could make treatment
of PWID cost-effective as well. The HCV treatment landscape is rapidly changing. Within 3–5 years, it is likely that IFN-free direct-acting antiviral therapies will be available with very high SVR rates (> 90% for all genotypes), short durations (8–12 weeks), high barriers to resistance, low toxicity, and once- or twice-daily oral-only dosing.[21-24] This could lead to dramatically higher uptake rates, particularly among PWID, especially if delivered in the community setting. Future work will need to examine the impact and cost-effectiveness of these IFN-free direct-acting antiviral
treatments for PWID, incorporating the prevention benefits of treatment so as to fully account for the advantages as well as disadvantages of treating PWID. Additionally, future analyses will need to evaluate the affordability Exoribonuclease of scaling up these new treatments to PWID for the purposes of reducing HCV transmission to very low levels, given the large numbers of people who need to be treated and the high cost of current treatments. NKM: This work is produced by NKM under the terms of the postdoctoral research training fellowship issued by the National Institute for Health Research (NIHR). The views expressed in this publication are those of the author and not necessarily those of the NHS, The NIHR or the Department of Health. PV: Medical Research Council New Investigator Award G0801627.