Comparison of adherence to generic multi-tablet regimens vs. brand multi-tablet and brand single-tablet regimens likely to incorporate generic antiretroviral drugs by breaking or not fixed-dose combinations in HIV-infected patients

First-line antiretroviral therapy initiation for newly diagnosed people with HIV in the Netherlands: A retrospective analysis from 2016 to 2020

INTRODUCTION

HIV treating physicians in the Netherlands follow the guidelines of the Department of Health and Human Services (DHHS). Most of these recommended initial regimens are single-tablet regimens (STRs), which incur higher costs. By the end of 2017, generic NRTI backbones had become widely available, offering a potentially cheaper multi-tablet regimen. This study aimed to evaluate guideline compliance in people with HIV who started antiretroviral therapy (ART), the uptake of generic multi-tablet regimens (gMTRs), and associated medication costs.

METHODS

This retrospective cohort study used data from the Dutch HIV Monitoring Foundation to determine the proportion of treatment-naïve people entering care who initiated ART according to the DHHS and type of ART regimens prescribed between January 2016 and December 2020. We analyzed ART prescriptions, both at the national level and per individual HIV treatment centers. We calculated the monthly ART costs based on Dutch medicine prices listed on www.medicijnkosten.nl for each calendar year.

RESULTS

In 2016, an integrase inhibitor-containing regimen was initiated in 77.3% which increased to 87.8% in 2020. The compliance rate to DHHS-recommended initial regimens ranged from 82.8% in 2016 to 90.9% in 2020. Most patients received single-tablet regimens, 81.3% in 2016 to 60.3% in 2020. After the introduction the gMTRs showed a steady increase from 17.8% in 2018 to 37.8% in 2020. The cost of the first-line regimen per patient decreased by 22.9% in 2020 compared with 2017. The decrease was larger in centers where treatment-naïve individuals with HIV were preferentially initiated on a gMTR.

CONCLUSIONS

There was a high compliance to the "DHHS-recommended initial regimens for most people with HIV" in the Netherlands. Most people who initiated ART received STRs, although the percentage of people who started on STRs gradually decreased over time. The use of gMTRs increased over time and was associated with lower medication costs.

Evergreened drugs or evergreened profits?

BACKGROUND

Branded drugs contribute disproportionately to high prescription drug spending. Pharmaceutical companies utilize patent extension "evergreening" techniques that contribute to high drug costs.

AIMS

This article describes various patent extension techniques and analyzes the tactic of combining generic drugs with branded drugs, using metformin combinations for diabetes treatment as a case study. It examines the argument that FDCs enhance adherence and compares the cost of several branded fixed-dose combinations with the cost of their individual constituents.

MATERIALS & METHODS

We reviewed literature on patent extension techniques in both medical and marketing literature, supplemented by our own extensive files. We performed a price analysis of several branded pharmaceuticals and generically available equivalents. Prescription drug prices were determined using GoodRx.com, and prices of over-the-counter products were established based on the prices of two chain wholesalers. Patent and formulation information was taken from the FDA Orange Book: Approved Drugs with Therapeutic Equivalence Evaluations database.

RESULTS

"Evergreening" patent extension tactics include the sequential release of different formulations, minor dosing changes, and fixed-dose combinations (FDCs). A "new use" provides an opportunity for a company to re-patent, rebrand, and remarket one drug for multiple indications. It is unclear whether or not FDCs enhance adherence. Branded fixed-dose combinations generally cost far more than their individual constituents. FDCs that combine metformin with other drugs are an exception, often costing the same as the non-metformin component.

DISCUSSION

Patent extension tactics increase drug costs while providing little additional benefit to patients. Minor alterations in formulations or dosing may provide no clinical benefits. Many FDCs are expensive and fail to provide cost-justified improvements in clinical outcomes, compared to equivalent generic drugs that would save money while delivering an equal standard of care. Combining newer hypoglycemic drugs with metformin, a gold-standard, generic, inexpensive drug, does not appear to cost more than individual constituents but offers no clinical advantage over metformin alone.

CONCLUSION

Evergreening tactics should be reined in, as they represent significant cost to the healthcare system and to patients. Physicians and other prescribers should avoid prescribing FDCs, or slightly tweaked "new" drugs. Patented drug combinations generate profit without innovation.

Patient-reported outcomes among people living with HIV on single- versus multi-tablet regimens: Data from a real-life setting

BACKGROUND

The use of single-tablet regimens (STRs) in HIV treatment is ubiquitous. However, reintroducing the (generic) components as multi-tablet regimens (MTRs) could be an interesting cost-reducing strategy. It is essential to involve patient-reported outcome measures (PROs) to examine the effects of such an approach. Hence, this study compared PROs of people living with HIV taking an STR versus a MTR in a real world setting.

MATERIALS AND METHODS

This longitudinal study included 188 people living with HIV. 132 remained on a MTR and 56 switched to an STR. At baseline, months 1-3-6-12-18 and 24, participants filled in questionnaires on health-related quality of life (HRQoL), depressive symptoms, HIV symptoms, neurocognitive complaints (NCC), treatment satisfaction and adherence. Generalized linear mixed models and generalized estimation equations mixed models were built.

RESULTS

Clinical parameters and PROs of the two groups were comparable at baseline. Neurocognitive complaints and treatment satisfaction did differ over time among the groups. In the STR-group, the odds of having NCC increased monthly by 4,1% as compared to the MTR-group (p = 0.035). Moreover, people taking an STR were more satisfied with their treatment after 6 months: the median change score was high: 24 (IQR 7,5-29). Further, treatment satisfaction showed a contrary evolution in the groups: the estimated state score of the STR-group increased by 3,3 while it decreased by 0,2 in the MTR-group (p = 0.003). No differences over time between the groups were observed with regard to HRQoL, HIV symptoms, depressive symptoms and adherence.

CONCLUSIONS

Neurocognitive complaints were more frequently reported among people on an STR versus MTR. This finding contrasts with the higher treatment satisfaction in the STR-group over time. The long-term effects of both PROs should guide the decision-making on STRs vs. (generic) MTRs.

Methods in pharmacoepidemiology

Pharmacoepidemiology is the study of interactions between drugs and human populations, investigating, in real conditions of life, benefits, risks and use of drugs. Pharmacoepidemiology applies to drugs and their pharmacological evaluations, the different methods also used in epidemiology to assess in real conditions of life, benefits, risks and use of drugs. Pharmacoepidemiologic studies are ad-hoc studies or studies on databases. Specific methods exist to measure drug exposure, as well as indicators of compliance and misuse of drugs. Various designs for descriptive and explanatory studies exist, in a context in which a growing proportion of studies are carried out using medico-administrative data. The limits traditionally affecting the study designs are modified in this context, almost any design selected for the conduct of a study from these databases then deriving from a cohort in whom the information has been recorded prospectively and exhaustively.