Page 32 - GHES-3-3

Global Health Economics and
Sustainability
Semaglutide for treating T2D and obesity

continuation. This highlights the urgent need for a set of and saxagliptin. Injectable semaglutide was also cost-
effective QALY measures to eliminate these socioeconomic effective in most comparisons with empagliflozin and
disparities (Nauck & Dietrich, 2022). canagliflozin (Laursen et al., 2023) (Table 1).

An interesting study examined the gained and total 8.3. T2D patients’ adherence profile of newer
costs from perspective of the Australian public healthcare, antidiabetic drugs
using data from the Australian Diabetes Registry (which
includes 1.1 million T2D patients), hospital admissions Medication adherence is crucial for T2D treatment success
databases, the National Death Index, and the End-Stage (Ogundipe et al., 2021). While primary adherence (the
Kidney Disease (ESKD) Registry. The study covered the rate at which patients fill prescriptions for the first time) is
critical for timely treatment of acute and chronic conditions,
period from 2010 to 2019 and used a simulation model
with real-world data to project cardiovascular disease and it has not been sufficiently explored. Most studies
ESKD morbidity and mortality from 2020 to 2040. Four evaluate adherence after one year, using electronic health
interventions were modeled, including increasing the use records (EHR). Ensuring adherence is key to effectively
managing T2D and improving healthcare costs and
of SGLT-2i or GLP-1RA to 75% of the total T2D population quality of life. Causes of low adherence are multifactorial,
and 75% of the secondary population (individuals with including patient-related factors (age), socioeconomic
T2D and prior atherosclerotic cardiovascular disease). factors (medication costs), condition-related factors
These interventions were compared with current use rates: (complications), health system-related factors (continuity
20% for SGLT-2i and 5% for GLP-1RA. The QALYs gained of care), and medication-related factors (adverse effects).
from 2020 to 2040 with increased use of these treatments The most frequent cause of low adherence is the severity of
in the total population were 176,446 for SGLT-2i and adverse events (Lee & Lee, 2022). Some adverse effects are
200,932 for GLP-1RA. The cost differences were estimated common with the consumption of antidiabetic medicines,
at AU$4.2 billion for SGLT-2i and AU$20.2 billion for GLP- particularly GLP-1RA, which are generally mild (Filippatos
1RA, with incremental cost-effectiveness ratios (ICERs) of et al., 2014; Gallwitz, 2019; Mishra et al., 2023; Tentolouris
AU$23,717 per QALY gained for SGLT-2i and AU$100,705 et al., 2019) (Table 2).
per QALY gained for GLP-1RA. In the secondary
population, the ICERs were AU$8,878 for SGLT-2i and Suboptimal adherence is a major barrier to optimal
AU$79,742 for GLP-1RA (Morton et al., 2022). treatment response in T2D patients. Medications leading
to at least 1% weight loss within 1 year are associated
For SGLT-2i users, increased adherence to therapy with better adherence. Early treatment with GLP-1RA
was associated with a reduction in healthcare costs, with compared to other antidiabetic agents improves glycemic
annual costs for non-adherent and adherent patients being control and weight loss, which, in turn, enhances adherence
€4952 and €4856, respectively. Although drug costs were (Durden et al., 2019). Suboptimal adherence is also linked
higher for adherent patients, adherence led to a reduction to increased mortality in T2D patients. Additionally,
in hospitalization costs (a savings of €96), and the ICER non-adherence has detrimental consequences, with once-
for the SGLT-2i cohort indicated an average gain of €53.3 weekly GLP-1RA injections showing a lower risk of non-
for each month free from events. For GLP-1RA, adherent adherence compared to daily dosing, leading to better
patients had higher annual costs (€5241 for non-adherent adherence and improved outcomes (Weeda et al., 2021).
and €6134 for adherent patients), primarily due to the Adherence is typically assessed by the proportion of days
higher cost of glucose-lowering drugs. Despite these high covered (PDC), defined as the number of days covered by
drug costs, adherence resulted in reduced hospitalization a medicine prescription divided by the number of days
costs. The ICER for GLP-1RA users indicated an average in the measurement period (Weiss et al., 2020). Patients
cost of €228 for each month free from events, with an are considered adherent if their PDC is ≥0.80 at any given
excess cost of €893 due to adherence (Ciardullo et al., time. Adherence patterns vary by gender and age, with the
2024). Another review compared the cost-effectiveness of most significant difference seen between daily and weekly
SGLT-2i, GLP-1RA, and DPP-4i for T2D and found that dosing (Weiss et al., 2020). Semaglutide once-weekly
the average annual treatment costs for GLP-1RAs were 2 (QW) demonstrated superior efficacy and safety compared
– 3 times higher than for SGLT-2i (empagliflozin), which to dulaglutide, liraglutide, and exenatide QW in T2D
was more cost-effective than DPP-4i (Zhu et al., 2023). patients in the United States. Adherence to semaglutide
Further studies showed that injectable semaglutide was QW was greater than that to liraglutide and exenatide
dominant compared to dulaglutide and sitagliptin, while QW, and comparable to dulaglutide, which showed higher
liraglutide was cost-effective compared to sitagliptin, and adherence than liraglutide and exenatide (Uzoigwe et al.,
empagliflozin was cost-effective compared to sitagliptin 2021). The higher adherence to semaglutide QW may be

Volume 3 Issue 3 (2025) 24 https://doi.org/10.36922/ghes.8547