More than a fifth of patients with hemophilia may now be using extended half-life (EHL) clotting factors, although the economic impact of these new treatments remains unclear.
Use of EHL factor VIII (FVIII) and IX (FIX) products surged from 10% of patients to 22% over an 18-month period ending in late 2017,and her colleagues reported in .
The increase appears to be mostly driven by prescribed prophylaxis rather than on-demand use of the products, wrote Dr. Croteau of Boston Children’s Hospital, and her coauthors. EHL dosages were similar to standard half-life (SHL) dosages and extended the time between infusions. But in the end, the higher cost of the EHL products actually drove up the price of prophylaxis, with a year of EHL FIX topping $1 million.
“Careful assessment of factor consumption and patient outcomes is needed to ensure general cost neutrality of this expensive therapy,” the researchers wrote. “Unless demonstrably offset by reduction in bleed doses, the net effect could be further increases in annual cost of care for this patient population.”
The study examined the use of SHL and EHL clotting factors in 7,893 adults and children with hemophilia A or B, who were being followed in the American Thrombosis and Hemostasis Network (ATHN) database. The authors sought to characterize changes in usage patterns for SHL and EHL factors, and to identify demographic and economic influences on them.
During the study, the number of patients using EHL products for both on-demand and prophylactic factor replacement increased. EHL FVIII use rose from 9% to 21%, and EHL FIX from 14% to 21%, especially among those with hemophilia B.
There were 6,437 patients with full data at both initial and final sampling. Among these, there was a 9.6% increase in the use of an EHL clotting factor by the end of the study (P less than .001). Patients with hemophilia A were less likely than hemophilia B patients to use an EHL product for prophylaxis.
While the EHL products did reduce the number of prophylactic infusions, they also cost much more, the investigators found.
The standard dose of SHL FVIII is 40 IU/g infused three times a week. The projected cost of 156 annual infusions is $690,144. EHL FVII, dosed at 50 IU/kg, cuts infusions to twice a week. The annual projected cost of the 104 infusions is $753,480.
The standard dose of SHL FIX is 67 IU/kg, infused twice a week. The annual projected cost of 104 infusions is $697,497. EHL FIX, dosed at 75 IU/Kg, halves the number of infusions. But the price for those 52 treatments exceeds $1 million ($1,015,560). Despite the cost, however, just 43 patients switched from an EHL product to a SHL factor product during the study period.
Insurance type appeared to have little influence on the choice of SHL or EHL clotting factors. Across payer types, a similar proportion of patients started using them, and 71% were covered by private insurance or Medicaid.
The study was funded HTRS/ATHN Dataset Research Engagement and a DREAM Award from the Hemostasis and Thrombosis Research Society. Dr. Croteau reported consulting for Bayer, Bioverativ, Biomarin, CSL-Behring, and other companies.
SOURCE: Croteau SE et al. Haemophilia. 2019 Apr 17. .