Exit strategies in patients with stable MS: Cost-effectiveness of extended interval dosing of ocrelizumab and natalizumab versus de-escalating to cladribine

Abstract

Background: Long-term treatment with standard interval dosing (SID) exposes MS patients to risks, but stopping treatment risks progression. Alternatives to stopping are 'exit strategies', such as extended interval dosing (EID) or de-escalating infection risks by switching to other DMTs.

Objective: To compare the cost-effectiveness of exit strategies for MS patients with stable disease on second line ocrelizumab or natalizumab.

Methods: We updated an existing treatment sequence model with time-dependent progression probabilities. Modeled exit strategies were: continue standard dosing, extend the dosing interval of ocrelizumab or natalizumab, or switch to cladribine. We applied a societal perspective, lifetime time horizon, discount rates for costs and QALYs of 3.0 % and 1.5 % and a cost-effectiveness threshold of €50,000 ($58.500) per QALY.

Results: Over two thirds of patients who received second line treatment fulfilled the stable-disease criteria to enter an exit strategy. EID strategies were more cost-effective than SID. An exit strategy to cladribine was >90 % likely to be more cost-effective than EID of ocrelizumab or natalizumab.

Conclusion: Adopting an extended dosing interval for patients who are stable on ocrelizumab or natalizumab is a cost-effective alternative to continuing treatment. De-escalating to cladribine is the most cost-effective exit option.

Keywords: Cost-effectiveness; DMTs; Exit strategies.