Budget Impact of Disease-Modifying Treatments and a CRISPR Gene-Edited Therapy for Sickle Cell Disease.

Background and objective: Treatment of sickle cell disease (SCD) has traditionally focused on symptomatic and preventative care. Recent advances in novel therapeutic developments, likely to be orphan-designated, are anticipated to carry a substantial price tag. This study assesses the potential budget impact of adopting disease-modifying treatments, crizanlizumab and voxelotor, and pioneering CRISPR gene-edited therapy, CTX001, in the Belgian healthcare system.

Methods: The perspective of the Belgian healthcare payer (RIZIV-INAMI including patient copayments), a 5-year horizon with a 2-10% uptake of disease-modifying interventions, and a 2% uptake of CTX001 were considered. Data, encompassing target population, current (chronic and acute management, curative hematopoietic stem cell transplantation) and new (crizanlizumab, voxelotor, and CTX001) interventions, clinical effectiveness, adverse events, healthcare resource utilization, and associated costs, were gathered through a comprehensive literature review (first phase) and two Delphi panels involving hematologists (second phase). The cost difference between a "world with and without crizanlizumab, voxelotor, and CTX001" was calculated to obtain the budget impact. Three scenario analyses were conducted: a 5-13% and 4% uptake analysis, a 10-18% and 8% uptake analysis, respectively for disease-modifying treatments (crizanlizumab and voxelotor) and CTX001, and a 0% crizanlizumab uptake and managed entry agreements analysis . A ± 20% univariate sensitivity analysis was performed to test the robustness of the analysis.

Results: The total five-year cumulative budget impact was estimated at €30,024,968, with 91% attributed to drug acquisition costs. The largest budget impact share was for CTX001 (€25,575,150), while crizanlizumab (€2,301,095) and voxelotor (€2,148,723) was relatively small. In scenarios one and three, a two-fold increase of the cumulative budget impact to €60,731,772 and a four-fold increase to €120,846,256 from the base case was observed. In scenario three, this budget impact decreased by 63% to €11,212,766. Patient population size, number of treated patients, and drug costs influenced the analysis the most, while discontinuation, acute crisis, and adverse event rates had comparatively minimal impact.

Conclusions: Belgian decision-makers may consider alternative financing models, such as outcome-based risk-sharing agreements or annuities, to ensure sustainable coverage of these treatments. This study adheres to recommended practices for assessing budget impact of orphan drugs, distinguishing it from earlier studies with potentially weaker methodologies.