Hemophilia B clinically less severe than A, though with similar QOL

ORLANDO – Despite clinical evidence that hemophilia B presents with less severity on a clinical level than hemophilia A, patients report similar quality of life and those with B have more obesity, according to a presentation at ASH Annual Meeting and Exposition.

“Overall, hemophilia B showed less clinical burden, lower cost and utilization of care. The health-related quality of life data wasn’t that different,” Randall Curtis, MBA, from McMaster University in Ontario, Canada, said during his presentation.

Curtis presented a comparison of the HUGS Va (n = 243; 2005-2007) and HUGS Vb (n = 107; 2009-2014) studies. The total participants included were split equally between adults and children.

At baseline, patients with hemophilia B (HB) presented with less clinical burden than those with hemophilia A (HA) and seemed to have fewer symptoms, Curtis said. Additionally, patients with HB incurred lower costs of care and health care utilization over the 2-year period studied

Median annual costs for adults with severe HB came in at $135,299 while those with severe HA tallied $317,961 (P = .001). Investigators observed a similar trend in children where pediatric severe HA patients had median annual total cost of $236,537 vs. $164,681 for pediatric severe HB patients (P = .04).

Median number of clotting factor units distributed was 2,963 IU/kg per year among adults with HA and 837 IU/kg per year among adults with HB (P = .001). Children with severe HB received less clotting factor units (3,817 IU/kg/year) vs. children with severe HA (6,281 IU/kg/year; P = .05).

Adults with severe HA had 0.52 mean number of ED visits while those with severe HB had 0.05 (P = .04).

Yet, quality of life scores did not show significant difference, Curtis said.

Using Short Form-12 Health Survey (SF-12) for adults and Peds QL 4.0 Generic Core Scales for children, the researchers saw that adults with both severe HA and severe HB showed lower SF-12 physical composite scores (PCS) than the general U.S. population. Adults with severe HB missed a median of 4 days of work vs. 7 days of work for adults with severe HA.

Children with both severe HA and HB reported greater PCS than the general U.S. population though children with severe HB reported greater PCS than those with severe HA.

“This is what I call the ‘happy hemo’ complex, which is based upon telling these kids how wonderful life is for them that they have factor and can play soccer, so they feel quite happy about themselves,” Curtis said.

Parents of children with severe HB missed fewer annualized work days than those with HA.

In looking at treatment and outcomes, Curtis reported that although adults with severe HB were more likely to use prophylaxis than those with severe HA (50% vs. 43%), the opposite was true for children. Children with severe HB were less likely to treat prophylactically than those with severe HA (64% vs. 84%; P = .03).

All adults with HA had a greater annualized bleeding rate (ABR) than those with HB (17.4 vs. 9.4; P .01). ABR among children with mild to moderate HB was lower than those with HA (3.4 vs. 6.2; P .01).

Children with HB reported more pain, but less joint range of motion complications than their HA counterparts.

More than two-thirds of patients in the total cohort had obesity, with 42% of children with severe HB having obesity compared with 20% of children with severe HA (P = .03). Curtis noted that the prevalence of obesity in hemophilia as a whole has economic and clinical implications.

“A and B, mild and moderate patients, tend to be overweight, which causes more bleeding episodes in the lower extremities,” Curtis said.

Curtis did note that the study of HB was done after that of HA, so that may affect the results. – by Katrina Altersitz

Reference: Curtis R, et al. Abstract 58. Presented at: ASH Annual Meeting and Exposition; Dec. 7-10, 2019; Orlando.

Disclosures: Curtis reports consulting for Bayer Foundation, CSL Behring, Novo Nordisk, Pfizer and Takeda.