Potential economic impact of dolutegravir/3TC dual therapy
Simon Collins, HIV i-Base
With cost driving so much in healthcare, the economic impact of a current experimental strategy might undermine the current dependence on three-drug combination therapy.
A study looking at the economic impact on US health costs if treatment with dolutegravir/3TC proves to be effective modeled five-year savings of $550 to $800 million based on 50% uptake of dual therapy for new patients starting ART. Savings reached more than $3 billion if only 25% of people currently stable on ART switched to dolutegravir/3TC dual-drug maintenance therapy. 
The model looked at various options depending on whether the reduced drug combinations are shown to be effective as initial treatment or as a switch strategy after viral suppression.
Early results presented at the 15th EACS conference in October 2015 hinted that reduced combinations using dolutegravir – with or without 3TC – might maintain viral load below detection, with little indication of viral rebound out to 24 weeks. [2, 3]
The paper rightly notes the ethics issue from recommending lower cost treatment that might be less effective, even if this is only marginally so. Currently we have insufficient data to know this.
The paper also notes that such a shift in prescribing would not be included in US treatment guidelines without data from a fully powered randomised study. Given current studies are still small underpowered and uncontrolled, this level of evidence is unlikely to become available for many years.
However, although this paper modelled US health costs, the results clearly have a significant impact on a global scale. Although international funding is impressive, it consistently fails to meet levels needed to ensure universal ART based on the current treatment strategies.
In addition to the other potential benefits of lower risk of drug interactions, side effects and drug resistance, generic dolutegravir plus 3TC looks likely to be available at a similar cost to generic first-line efavirenz-based combinations and significantly less expensive than all current second-line combinations. 
- Girouard MP et al. The cost-effectiveness and budget impact of two-drug dolutegravir-lamivudine regimens for the treatment of HIV infection in the United States. Clin Infect Dis. (2015). doi: 10.1093/cid/civ981. Published online: 9 December 2015.
- Collins S. Remarkable results with dolutegravir monotherapy. HTB November/December 2015.
- Collins S. First-line ART with dolutegravir plus 3TC: 24-week early results. HTB November/December 2015.
- UNAIDS, CHAI and UNITAID. Joint press announcement. Three new agreements announced with the potential to expand access to innovative HIV treatment in low- and middle-income countries. (30 November 2015).