Injection Therapy Like Hemlibra Favored Over Infusions by Adults
Adults across the general public in Canada think an under-the-skin injection treatment for hemophilia A would be preferable to those needing to be infused intravenously, or directly into a vein, a study based on interviews reported.
Results of the analysis, sponsored by Roche Canada and conducted by Broadstreet HEOR and Sprout Health Solutions, reflected preferences voiced in other studies by patients with various diseases, its researchers noted, and could be of use in a Canadian cost-utility analysis of different treatment administration routes.
“Our findings were consistent with similar studies in other disease states that show preference for subcutaneous injection versus infusion,” Karissa Johnston, PhD, principal and scientific director at Broadstreet HEOR and lead author of the study, said in a press release.
“Additionally, there were a number of noteworthy observations from the qualitative research executed to inform the survey development, including the prevalence of significant psychological and physical difficulties for patients and caregivers related to prophylaxis or on-demand intravenous infusions,” Johnston added.
The study, “Preferences and Health-Related Quality-of-Life Related to Disease and Treatment Features for Patients with Hemophilia A in a Canadian General Population Sample,” was published in the journal Patient Preference and Adherence.
For people with hemophilia A, replacement therapy with FVIII — the blood clotting protein they are missing — is standard practice. Although preventive treatment with FVIII has benefits, such as preserving joint function, many patients develop inhibitors. These neutralizing antibodies target FVIII and reduce a treatment’s effectiveness, rendering it useless in some cases.
Preventative treatments, largely delivered intravenously, can be time-consuming, burdensome, and significantly impact patients’ quality of life.
Hemlibra (emicizumab), an approved treatment for managing the symptoms of hemophilia A, is administered as an under-the-skin (subcutaneous) injection. (Hemlibra was approved by Health Canada, and by regulators in the U.S. and the European Union, in 2018.)
The therapy, marketed by Genentech (a member of the Roche group), is an antibody that promotes blood clotting by mimicking the activity of FVIII. Hemlibra is currently the only available under-the-skin therapy, but similar treatments are likely to come into future use.
Four Phase 3 clinical trials — all part of the HAVEN program — have shown that Hemlibra is effective at preventing bleeding episodes in patients with hemophilia A with and without inhibitors. Many study participants also stated their preference for Hemlibra over other treatments, possibly because of its convenience and lower overall burden.
In this study, researchers set out to understand the perspectives of the general Canadian public regarding hemophilia A and treatment burden faced by patients, as well as their own preferences regarding treatment options.
The team determined health state values, or utilities, related to the mode of treatment administration in hemophilia A. Utilities represent a person’s preference for being in a particular health state, and are generally a number between 0 (representing death) and 1 (perfect health).
In-depth interviews in the form of vignettes were conducted. Vignettes are short stories about hypothetical people or situations that are used to elicit a respondent’s judgment of these scenarios.
This approach was used to gather and compare the preferences of Canadian adults on six health states describing different preventive and on-demand hemophilia treatments, each associated with varying bleed rates and dosing frequency.
Health states were developed based on the experiences of two clinical investigators, and qualitative interviews with eight adult caregivers of children with moderate to severe hemophilia A and with two adults with moderate to severe disease.
Two different versions were drafted for health states and vignettes: one reflecting a child with hemophilia, and the other an adult with hemophilia. Respondents were randomly allocated to one of the two versions.
Vignette interviews were conducted with 82 adults across Canada (59% women and 41% men); 44% answered the adult version of the survey, and 46% the pediatric version.
Findings showed that mean utilities were highest for under-the-skin preventive treatment (0.90), followed by intravenous preventive therapies (0.81), and on-demand treatments (0.70).
Further analysis showed that under-the-skin treatment health states were associated with a utility increase of +0.1112. Conversely, additional bleeds and more frequent infusions were associated with lower utility values (− 0.0027 per bleed and − 0.0003 per infusion).
“Our conversations with patients and caregivers reinforced the onerous treatment process with infusion therapy that poses a daily psychological and process burden marked by emotional stress, decreased quality of life and non-adherence,” said Lina Eliasson, PhD, a partner at Sprout Health Solutions.
Qualitative research, Eliasson added, revealed a strain on caregiver/child relationships caused by difficult infusion regimens that required frequent and often painful procedures.
“It was also apparent that real-world treatment by infusion does not necessarily translate to fewer bleeding episodes, in contrast to what many hematologists believe,” Eliasson said.
Although findings highlight a clear preference among the general public for a subcutaneous rather than an intravenous treatment, as well as for treatments requiring less frequent dosing, the scientists noted that further research in patients is required.
“We captured preferences indicated by the general public based on descriptions of relevant health states; actual experience of such health states by hemophilia patients are additionally of interest but given the recent introduction of subcutaneous treatments for this patient population, such a study is not feasible at this time,” the researchers wrote.