Little interest in gene therapy for many with severe hemophilia: German study
Findings suggest patients may not have accurate info on benefits, risks
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A small survey study in Germany found that many people with severe hemophilia are not interested in receiving gene therapy, despite having “only general knowledge” of the treatment option — which, the researchers noted, could be “a potential cure with a single infusion.”
According to the scientists, these findings suggest that some people with hemophilia may not have accurate information about the benefits and risks of gene therapy, a one-time treatment that has been shown to provide long-lasting symptom management for certain patients.
The team noted that more than half of the 69 men surveyed “expressed a predominantly rejective attitude toward gene therapy.”
This highlights a need for continued educational efforts, the researchers said, noting that gene therapy “has not yet gained widespread acceptance” among patients.
“Further studies are needed to refine educational concepts for people with hemophilia and clear out misconceptions about gene therapy,” the team wrote.
The study, “An analysis of attitudes toward gene therapy in people with severe hemophilia in Germany, a survey-based cross-sectional study,” was published in the journal Therapeutic Advances in Hematology.Â
Hemophilia refers to a group of bleeding-related disorders that are characterized by defects in proteins needed for blood clotting in patients. The condition results in symptoms such as unusually easy and prolonged bleeding. Hemophilia A is caused by reduced function of clotting factor VIII, while reduced activity of clotting factor IX marks hemophilia B.
For both these main hemophilia types, the cornerstone of treatment has long been factor replacement therapies, in which a functional version of the dysfunctional clotting protein is administered to treat and/or prevent bleeds.
2 hemophilia gene therapies now approved in US, Europe
In recent years, gene therapy has emerged as a promising approach for the treatment of hemophilia. The basic idea is to deliver to the body’s cells a healthy version of the gene encoding the relevant clotting protein, allowing the body to produce its own functional clotting factor protein to control bleeding.
In the U.S. and Europe, the gene therapies Roctavian (valoctocogene roxaparvovec-rvox) and Hemgenix (etranacogene dezaparvovec-drlb) are approved for certain patients with hemophilia A or B, respectively.
In theory, gene therapy offers a one-time treatment that can provide long-term symptom relief. But like with any medication, there are associated risks as well as potential benefits. Among these risks, available hemophilia gene therapies can cause liver damage, and because they introduce new genetic material into the cells, it’s possible that these treatments might increase cancer risk, though currently this risk is largely theoretical.
Also, because hemophilia gene therapy is a new approach, much about the long-term impact of such treatment remains unknown.
To understand how people with hemophilia weigh out the potential benefits and risks of this cutting-edge treatment approach, scientists in Germany conducted a patient survey. It was answered by a total of 59 men with hemophilia A and 10 with hemophilia B. All had severe disease, defined as clotting factor levels less than 1% of normative values. Nearly all were receiving regular replacement therapy or other prophylactic (preventive) treatments to manage bleeding.
The survey respondents generally reported being satisfied with their current treatments. Nonetheless, the researchers highlighted that most of them experience chronic joint pain — an issue that can arise in hemophilia due to bleeding into joints — and nearly half said they avoid participating in sports due to the risk of bleeds.
“Overall, 83% of patients reported that they had experienced limitations in various aspects of their lives as a result of their disease,” the researchers noted.
Respondents found to have little objective knowledge of treatment
About two-thirds of the respondents said they had heard of gene therapy, mainly from their doctors or from patient organizations. However, in parts of the survey designed to assess respondents’ objective knowledge about gene therapy, scores were generally poor. In fact, most respondents got fewer than half of the questions right, with 7% in total scoring more than 80%. None got all of the questions correct.
Per the team, these data highlight a need for continual efforts to give patients accurate information about the benefits, risks, and unknowns of gene therapy.
When asked if they would consider undergoing gene therapy, more than half of the respondents — 59% in total — said they were not interested.
The researchers conducted statistical analyses to compare patients who said they would consider gene therapy against those who would not. Both groups were similar in terms of demographics, but patients who were open to gene therapy were more likely to have higher bleeding rates.
“Rejection was unrelated to age, education, or pain level, but [people with hemophilia who experience at least one bleed per year] were more willing to consider [gene therapy],” the researchers wrote.
The scientists stressed that this survey involved few patients, most of whom were in their 30s or older, and as such, the results cannot be extrapolated to all people with hemophilia. Still, the team said the findings could help researchers better understand patients’ attitudes toward gene therapy, as well as highlight a need for continual educational efforts.
This study was funded by the Coagulation Center and Hemophilia Center at Frankfurt University Hospital. One of the coauthors disclosed receiving funds from, among others, BioMarin Pharmaceutical, which markets Roctavian, and CSL Behring, which markets Hemgenix.
