The Impact of Price Reductions After Loss of Exclusivity in a Cost-Effectiveness Analysis: Fingolimod Versus Interferon Beta-1a for the Treatment of Relapsing-Remitting Multiple Sclerosis.

BACKGROUND

Cost-effectiveness analyses tend not to take into account the availability of lower-priced generics following loss of exclusivity (LOE) of branded products. By not considering these generics, which are typically adopted quickly, total costs are likely to be overestimated and may be unreflective of real-world payer conditions in the United States.

OBJECTIVE

To assess the impact of including future price reductions following LOE on the cost-effectiveness of fingolimod versus intramuscularly administered interferon beta-1a (IM IFNβ-1a) as treatments for multiple sclerosis.

METHODS

This model was adopted from a previously published Markov model and was conducted from a U.S. payer perspective over a 10-year time horizon. Patients with relapsing-remitting multiple sclerosis entered the model and received either fingolimod (an oral therapy) or IM IFNβ-1a (an injectable). These treatments reflect the interventions studied in the TRANSFORMS randomized clinical trial. Clinical, cost, and utility inputs were based on a recent cost-effectiveness review of therapies for multiple sclerosis. To model LOE, price reductions and the proportion of patients switching to generic versions following LOE were based on published estimates. Price reductions varied to reflect the difference in product types (oral vs. large molecule injectable). Assumptions were also made around the proportion of patients switching to generic versions over time following LOE and the projected date of LOE. Outcomes included per-patient total direct costs (medication, administration and monitoring, and disease-related costs including relapses), quality-adjusted life-years, and the incremental cost per quality-adjusted life-year.

RESULTS

Assuming no price reductions following LOE, fingolimod was considered cost-effective versus IM IFNβ-1a ($118,434 per quality-adjusted life-year), despite having higher total direct costs over 10 years ($475,740 vs. $446,792). When including future price reductions following LOE, total direct costs were reduced with fingolimod and were lower than those accrued with IM IFNβ-1a over the model time horizon ($308,570 vs. $442,653). Cost-effectiveness results were sensitive to changes in both clinical parameters and medication costs. Scenario analyses demonstrated that an earlier date of LOE was associated with lower total costs.

CONCLUSIONS

Health economic models may predict higher total costs when the price reductions following LOE are not considered. Here, oral fingolimod was seen to be cost-saving versus IM IFNβ-1a over the model time horizon when such price reductions were included. The cost implications of not accounting for future price changes may determine whether an intervention is considered cost-effective and as such may influence reimbursement decisions based on cost-effectiveness thresholds. Multiple product types (e.g., oral, injectable, and infused agents) have been approved for use as treatments for multiple sclerosis in the United States, and LOE is likely to have a different effect on each of these therapies.

DISCLOSURES

This study was funded by Novartis Pharmaceuticals Corporation. Hua and Hersh report consulting fees from Novartis for work on this study. Hua also reports speaking, advisory board, and consulting fees from Biogen, Genzyme, Teva, EMD Serono, Genentech, TG Therapeutics, and Novartis for activities outside of this study. Hersh also reports speaking and consulting fees from Novartis, Biogen, Genzyme, Genentech, and EMD Serono for activities outside of this study, and research grants from PCORI and Biogen. At the time of this research, Morten and Kusel were paid employees of Costello Medical, which was contracted by Novartis to undertake some of this study's work. Lin, Cave, Herrera, and Ko were paid employees of Novartis at the time of this research. Cave, Herrera, and Ko also report owning stock in Novartis Pharmaceuticals. Varga provided services to Novartis at the time of this research and has nothing further to disclose. This research was presented as a poster at the AMCP Managed Care & Specialty Pharmacy Annual Meeting 2017; March 27-30, 2017; Denver, CO.