First-line anti-retroviral virological suppression test using a drug regimen of dolutegravir (Tivicay) and lamivudine would be highly cost-effective and could save around $ 500 million health systems over five years, according to the results of a mathematical model published in the online edition of Clinical infectious diseases.
A Switching a quarter of immunosuppressed patients to the regimen with the combination of two drugs could reach five annual savings of $ 3 billion.
"We want to demonstrate that the maintenance strategy induction of three-drug therapies initial with DTG / ABC / 3TC [Dolutegravir / abacavir / lamivudine] followed by DTG + 3TC as maintenance scheme would have cost-benefit in the US under plausible hypothesis virological efficacy and DTG + 3TC as initial therapy could be even more cost-effective, "comment the researchers. "We found that the induction and maintenance of two drug strategies, if approved, could save more than $ 500 million, or $ 800 million, respectively, on HIV patients, therapy costs in the first five years compared to current standard of care. "
The findings of the study are described as "important" by the authors of an editorial, which suggest that the cost reduction achieved effectively in dual drug therapy could be used to improve engagement rates and retention in care, both critical to controlling the epidemic of HIV in the United States.
The first line of HIV therapy is usually composed of three antiretroviral drugs in two distinct classes. This treatment usually costs up to 30.000 dollars per patient / year.
The results of a pilot study presented to the 15th European AIDS Conference this year, demonstrated that the first line of treatment with only two drugs - a potent integrin dolutegravir inhibitor with lamivudine - had excellent virologic efficacy during 48 weeks, with a good safety / toxicological profile. The full results will be published in the year 2016.
The researchers wanted to see if this dual combination of drugs could be cost-effective and estimate the potential savings that could be achieved if it were to be used in first-line treatment strategies.
They built a model involving four treatment strategies for patients in the United States.
- Treatment - for modeling comparison.
- Initial treatment with dolutegravir and lamivudine.
- Induction and maintenance therapy - an initial of three dolutegravir / abacavir / lamivudine medications, followed by maintenance therapy with dolutegravir-lamivudine in patients with virologic suppression following 48 weeks of induction therapy.
- Standard of care - drug therapy with three drugs dolutegravir / abacavir / lamivudine.
The authors calculated the cost-effectiveness (defrost) for each strategy in relation to the near least expensive strategy. The strategy was considered to be cost-effective if the DEGEL was below the threshold of $ 100.000 dollars per quality of life per year (QALY). The annual economic quality of life in health is a year of perfect health and the thaw is the extra cost of buying a year of perfect health with a new intervention in relation to the current level of care.
It is estimated that 93% of patients have virologic suppression after 48 weeks of treatment with drugs. The researchers adopted a cautious approach to the effectiveness of dual drug therapy, assuming that 87% of patients have a viral load below 50 copies / ml after starting treatment with this combination. They also assume virologic failure at a rate of 0,6% per month for patients taking maintenance therapy for two drugs; this compared to a monthly failure rate of 0,1% for patients who received the standard treatment.
After applying the discounts, the cost of annual treatment with dolutegravir / abacavir / lamivudine was $ 24.500 and annual treatment with dolutegravir-lamivudine was calculated as costing $ 15.200.
The five-year survival rate was 90% for standard care, induction and maintenance therapy and two for drug treatment. The proportion of patients who remained on first-line treatment in the fifth year ranged from 97% to patients receiving standard treatment and from 89% to patients who received the first two drug therapies.
Regarding no type of treatment, the DEGEL for induction and maintenance therapy was US $ 22.500 / QALY. Regarding induction and maintenance therapy, the standard of care DEVELOPMENT was more than $ 500.000 / QALY and was not cost-effective. The clinical and economic results of two drug treatments were almost identical to induction and maintenance therapy (DEGEL in relation to no treatment, $ 26000 / QALY).
50% of fixation by patients starting HAART-inducing maintenance therapy or two-drug therapy was calculated to achieve a "five-year" cost reduction of $ 550 million and $ 800 million respectively. Economics reached $ 3 billion if 25% of immunosuppressed patients were tied to dolutegravir-lamivudine therapy.
"Given the great potential for economic benefit coupled with excellent clinical outcomes, if the upcoming pilot study data are promising, some fully-equipped clinical trials to assess non-inferiority of these strategies should be done," the researchers conclude.
The findings of the study are described as "innovative and appealing" in the editorial, commented the authors, "two drug strategies offer real possibilities to reduce the costs of HIV treatment not only in the United States but in other countries."
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, online edition, 2015.
Koenig SP et al. Stemming the tide: can new approaches to HIV treatment reverse the trend of rising drug prices in the United States? Clin Infect Dis, online edition, 2015.