At current pricing, the price of prophylactic emicizumab would need to decrease by >35% to become cost-effective in US adults with moderate or mild hemophilia A without inhibitors, according to research published in the American Journal of Hematology.
“Prior studies have analyzed the cost-effectiveness of prophylactic emicizumab in the context of patients with severe hemophilia A,” the researchers wrote in their report. “The cost-effectiveness of emicizumab in patients with non-severe hemophilia A without inhibitors is not currently known.”
The investigators examined the cost-effectiveness of prophylactic emicizumab compared with prophylactic standard recombinant FVIII in adults with moderate or mild hemophilia A without inhibitors in the United States. They developed a model to evaluate quality-adjusted life expectancy and costs for patients with moderate or mild hemophilia A without inhibitors enrolled in the HAVEN 6 trial.
The model used a lifetime time horizon with a 1-month cycle, an annual discount rate of 3% for cost and health outcomes, and a US payer perspective at a willingness-to-pay threshold (WTP) of $150 000 per quality-adjusted life year (QALY).
Patients were assigned to either emicizumab prophylaxis or standard recombinant FVIII prophylaxis. Within each arm, the model included 5 disease states, starting with no new bleeding event and without long-term joint damage, which could accrue over time. From this state, patients could experience no new bleeding event, a new treated bleeding event without hemarthrosis, a new treated bleeding event with hemarthrosis, joint replacement surgery for accrued long-term joint damage, or death, based upon sex- and age-dependent US background mortality.
With each bleeding event, patients received treatment according to World Federation of Hemophilia guidelines and returned to the no bleeding state for repeat cycles, in which they were exposed to the same risks.
The primary outcome was the incremental cost-effectiveness ratio (ICER) for the use of prophylactic emicizumab compared with that of prophylactic standard recombinant FVIII. Secondary outcomes were threshold analyses for the chronic arthropathy reduction with prophylactic emicizumab use and the price of emicizumab that would make prophylactic emicizumab cost-effective.
In the model, patients who received emicizumab prophylaxis experienced 62% fewer treated bleeding events and 64% fewer hemarthrosis events over their lifetime than those who received recombinant FVIII prophylaxis.
The study showed the emicizumab strategy accrued 18.9 discounted QALYs at a discounted cost of $17,400,000, while the standard-of-care strategy accrued 18.5 discounted QALYs at a discounted cost of $11 600 000. These findings translated to an ICER of 14.5 million USD/QALY (95% credible interval, $8 530 000-$28 400 000/QALY) for prophylactic emicizumab compared with the standard of care. In the probabilistic sensitivity analysis, prophylaxis with standard recombinant FVIII was favored in 100% of the model iterations.
The threshold analyses demonstrated that a 100% reduction in the prevalence of chronic arthropathy would decrease the ICER to $1,160,000/QALY and that the cost of 1 mg of emicizumab would need to decrease by approximately 35% to be cost-effective at a WTP of $150,000/QALY.
“In conclusion, at current pricing, prophylactic emicizumab was found to be a cost-ineffective strategy in patients with moderate or mild hemophilia A without inhibitors over a lifetime time horizon in the United States. This conclusion holds even if prophylactic emicizumab were to decrease chronic hemophilic arthropathy to 0%,” the authors noted. “Indication-based pricing across existing expensive medications, such as emicizumab for patients with moderate or mild hemophilia A without inhibitors, would aid the goal of a value-based care transformation of the United States’ health system — that is, improving patient outcomes at costs commensurate with clinical improvement.”
Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, or device companies. Please see the original reference for a full list of authors’ disclosures.
Potnis KC, Viswanathan G, Bona RD, et al. Cost-effectiveness of prophylactic emicizumab versus prophylactic recombinant factor VIII in patients with moderate or mild hemophilia A without inhibitors in the United States. Am J Hematol. Published online July 4, 2023. doi:10.1002/ajh.27014