Haemophilia A is an orphan disease caused by a faulty gene that is unable to produce an essential protein that is necessary for blood clotting – factor VIII.

There are three forms of haemophilia A – severe, moderate, and mild. The majority of the cases are passed down from parents to children, but about 1/3 of them are caused by a spontaneous mutation. Patients with haemophilia A often bleed more, and longer, and bleeding can occur internally into joints and muscles or externally from minor cuts or trauma. Current treatment includes monoclonal antibodies and concentrated factor VIII. This therapeutic approach requires high treatment adherence and leads to significant discomfort due to its intravenous administration. Furthermore, patients must alter the timing and degree of physical activity to match the metabolism of factor VIII. Severe cases require an effective prophylaxis regimen to maintain a sufficient level of clotting factors to prevent bleeding.

Gene therapy provides treatment and prevention of diseases by correcting the underlying genetic problems instead of using drugs or surgery. The therapy consists of various approaches. First of them is gene transfer which is introducing an additional gene into specific cells to become part of the cell’s DNA and compensate for abnormal genes or missing proteins. The second approach is gene editing – which consists of technologies targeting a specific piece of DNA. If a healthy donor DNA is delivered, it will be copied into the patient’s genome, and it ensures restoration of gene activity. The third approach is nucleic acid therapeutics – treatment is realized by using non-coding small pieces of RNA and DNA, which alter how the genetic code is read to produce protein. Genetic material is introduced into cells to compensate for abnormal genes, replace a dysfunctional protein or introduce a beneficial protein. The genes are delivered to the cell by gene carriers – vectors that are modified viruses capable of integrating genetic material into a human chromosome or nucleus. These therapies are priced at a much higher premium than traditional treatments due to increased development and manufacturing costs. The lack of statistically significant evidence for the long-term clinical efficacy of gene therapy represents a leading financial challenge. There are currently more than 1200 clinical trials studying the therapeutic potential of gene therapy. Most of these trials are in Phase II and III.

Haemophilia A: What potential breakthrough are we awaiting?

Gene therapy for haemophilia A may improve patient quality of life and disease management by reducing the risk of spontaneous haemorrhages and long-term disabilities. This therapeutic approach will provide enhanced productivity and higher economic contribution. Gene therapy will replace the use of high-cost factor VIII therapy. This approach will reduce the expenditure on treatment for co-morbidities associated with frequent haemorrhages.

How will this approach help the patients?

This novel approach provides an effective therapeutic potential following a single administration, which represents a paradigm shift in haemophilia A treatment and will replace the need for long-term therapy. Gene therapy will offer patients the opportunity to live a more active lifestyle and lower the severity of haemorrhages. Effective treatment and screening require care provided by multidisciplinary teams, including haematologists, physiotherapists, dentists, and orthopaedists. Haemophilia A can lead to severe intracranial haemorrhages, which require hospitalization. Complications lead to deterioration in professional engagement and significant expenditure on public resources, which greatly burden on the healthcare system. Reduction in risk of spontaneous haemorrhages will offer patients the opportunity to improve their levels of physical activity. This approach will contribute to elevated professional and economic benefits.

How many patients will be concerned?

The number of cases of haemophilia A in Europe exceeds 31 thousand. To prevent severe complications and haemorrhages, patients need long-term and effective maintenance of a sufficient level of clotting factors. Current treatment for haemophilia A requires a high expenditure on healthcare and represents a leading financial challenge. Gene therapy will provide an effective therapeutic potential following a single administration, reducing the treatment burden and complications of haemorrhages.

What will be the potential impact on healthcare systems in Europe?

This novel approach will reduce the expenditure on prophylactic therapy by up to 90%. Controlling the risk of severe haemorrhages will ensure reduced hospitalizations and associated costs. In this manner, gene therapy will contribute to a more effective allocation of health resources and improved access to healthcare. Replacing long-term therapy will cause a decline in consultation expenditure and overhead clinic costs.

DISCLAIMER

The therapies described above are currently under development and are not available to patients neither in Europe, nor in Bulgaria.