DAA not cost-effective as first-line therapy for genotype 3 HCV in Singapore
At its current prices, the use of direct-acting antivirals (DAA) as first-line therapy for genotype 3 (GT3) hepatitis C virus (HCV) in Singapore is not cost-effective, especially as compared to pegylated interferon and ribavirin (PR), according to a new study.
“It is important to clarify that this study and its findings do not seek to undermine the value of DAA in treating GT3 HCV,” noted researchers. “Rather, it seeks to determine the price at which DAA therapy becomes cost-effective, or at the very least cost-neutral, for widespread use.”
Through a decision tree analysis, researchers found that in the base case analysis, which included undiscounted prices, DAA treatment with daclatasvir, ribavirin and sofosbuvir yielded a quality-adjusted life year (QALY) value of 0.69 at a cost of USD 54,634. In comparison, first-line therapy with PR led to a QALY of 0.62 while costing only USD 23,857. [JGH Open 2019;3:210-216]
The resulting incremental cost-effectiveness ratio (ICER) of the DAA compared with the PR regimen was USD 449,232 per QALY.
In Singapore, the gross domestic product in 2016 was USD 53,302. Using this value as the willingness-to-pay (WTP) threshold, researchers noted that the first-line DAA regimen with daclatasvir, ribavirin and sofosbuvir was not cost-effective.
Subsequent one-way sensitivity analyses found that the base case model was robust to variations in model parameters, such as weekly costs of DAA, probability of sustained virological response with PR and the weekly cost of hospitalization while on PR medication, among others.
Threshold analysis further showed that to be cost-effective, weekly DAA costs should be capped at USD 1,416.8, and that a 12-week regimen should not exceed USD 17,002.
“While the introduction of highly effective DAA in recent years has expanded the treatment armamentarium of HCV patients, the prohibitively high cost of DAA remains a barrier for treatment access for HCV patients in Singapore,” said researchers.
“[O]ur study demonstrated that, at the present prices outlined above, DAA is not cost-effective as first-line treatment for GT3 HCV patients compared with PR,” they added.
To adjust for the price changes over time, researchers utilized the discounted prices of DAA (with sofosbuvir and velpatasvir; USD 2,577 per week) and PR (USD 287 per week). Overall, this new DAA regimen resulted in a QALY of 0.68 at a total cost of USD 33,025.56, while PR yielded a QALY of 0.62 while costing USD 17,086.19. While the resulting ICER was lower (USD 259,196.18), the DAA regimen continued to exceed the WTP threshold.
“In Singapore, the cost of healthcare is not fully subsidized by the state or insurer and operates on a copay system,” said researchers. “Even though the cost of inpatient healthcare is partially subsidized by the state, the cost of outpatient care, including the cost of medications, is borne by the patients. Thus, the high cost of DAA can become a barrier to treatment access for HCV patients.”
“Revision of current DAA prices will help policymakers implement the widespread nationwide elimination of HCV with a reasonable budget impact,” they added.