How new hemophilia products could usher in personalized treatment strategies
This year could see the first regulatory submission from a coming wave of new therapies for hemophilia prophylaxis that do not simply replace missing clotting factors, which has been the standard for care for decades. These new products could enable a more personalized approach to treating subsets of patients based on disease severity and individual preference.
The most advanced is a mAb in Phase III testing that mimics the biological role of Factor VIII. Four earlier stage programs are focused on rebalancing the coagulation cascade (see “Next Wave in Hemophilia”).
Especially for patients who develop neutralizing antibodies to standard clotting factor replacements, these new strategies could provide an alternative to tolerization therapy, which helps some patients but leaves others dependent on acute treatment for bleeding episodes.
For other patients, the new agents could reduce the frequency, difficulty and invasiveness of treatment, which keeps some patients from taking prophylactic drugs.
“The fact that you can dose it subcutaneously is a big deal.”
Yet getting uptake for these treatments beyond patients who cannot or do not take factor replacements will be challenging. Hemophilia patients and the physicians who treat them generally prefer to stick to products they know and trust, and the market has been flooded with factor replacement products. In the last three years alone, six long-acting factor replacements that reduce the frequency of IV dosing have been launched.
In other settings where switching behavior is low, treatment-naïve patients would be the first targets for new drugs. This population in hemophilia could derive the greatest long-term benefit from improvements in coagulation because most are young children who have not experienced irreversible damage due to chronic bleeds. However, the newer drugs have barely started to be tested in children (see “Pediatric Paradox”).
Companies are therefore collecting data to show how these non-factor therapies could improve outcomes and reduce costs of interventional care, which could help build the case for getting patients to switch and payers to reimburse the new therapies.
There may be a limited window in which to gain a toehold. Gene therapies that seek to unseat the prophylactics could begin to hit the market as early as 2020. Whether they render rebalancing or factor-mimicking therapies moot will depend on their ability to provide durable expression of clinically meaningful amounts of factor.