PIN20 Budget Impact of Backbone Choice in Italian Treatment- Naïve, HIV-Infected Patients

Abstract

The gradual increase of persons living with HIV, mainly due to the reduced mortality achieved with effective antiretroviral therapies, calls for increased rationality and awareness in health resources consumption also during the early illness phases. Aim of this work is the estimation of the budget impact related to the variation in backbone prescribing trends in naïve patients. Target population is the number of patients starting antiretroviral therapy each year, according to the Italian HIV surveillance registry, excluding patients receiving non-authorized or non-recommended regimens. We modeled 3-year mortality and durability rates on a dynamic cohort, basing on international literature. Current Italian market shares of triple regimens containing first-choice backbones (TDF/FTC, ABC/3TC, TDF+3TC, AZT/3TC) are compared to an hypothetical scenario in which all patients eligible to ABC/3TC treatment (HLA-B*5701 negative patients with <100,000 HIVRNA copies/mL) start a regimen containing this backbone as first line strategy. Annual cost for each regimen comprises drugs acquisition under hospital pricing rules, and monitoring exams and preventive tests, valued basing on regional reimbursement tariffs. According to current prescribing trends, in the next three years about 13,000 patients starting HIV therapy will receive TDF/FTC (83% of the target population), and minor portions other regimens (9% ABC/3TC, 8% AZT/3TC). Patients that would be eligible to ABC/3TC are about six thousand more than those presently treated with this backbone, leading to a saving of 3.1 million Euro over the three-year period. Sensitivity analyses on different hypotheses of “third” drug market shares indicate savings ranging from 720 thousand to 3.9 million Euro. Most of this amount is due to reduced acquisition costs and, secondarily, to lower monitoring needs. Where patient features don't force the choice of the backbone, ABC/3TC prescription may induce substantial savings, allowing the release of resources needed to manage more complicated/advanced cases.