“The future looks bright for hemophilia,” said Marijke van den Berg, MD, WFH Vice-president Medical, during her plenary lecture addressing past, present and future treatment developments in hemophilia.
Van den Berg first talked about the disparities in clotting factor concentrate uptake between developed and developing countries and stated that this must change. She then went on to describe how prophylaxis has brought great advances in the treatment of hemophilia, particularly severe cases in which an increase in trough level to two or three per cent results in a dramatic reduction in bleeding. “However, prophylactic treatment took a long time to be accepted,” said van den Berg, “as did the recognition of the need to start prophylactic treatment early.”
“We are moving from a model of shortage to a model of plenty,” said van den Berg, “but this explosion of new therapies makes treatment choice ever more important.” Van den Berg described the need for treatment to be individualized according to age. “There is pharmacokinetic variability between products, so you must take this into account and dose accordingly.”
It is also necessary to properly address the rebalancing of hemostasis. “Hemostasis is complex,” she said, “and a low level of rebalancing can lead to a high risk of bleeding and thrombosis.”
Van den Berg then discussed up-and-coming therapies, including the promising drugs emicizumab and fitusiran, both of which are in clinical development. The subcutaneous route of administration of these drugs will further facilitate treatment, and the recent explosion of new products for hemophilia will make it easier to individualize treatment and lower the disease burden.
Van den Berg talked about the exciting area of gene therapy, focusing on two recently published early-stage clinical trials of gene therapy in hemophilia A and B. These trials demonstrate that gene therapy brings about sustainable levels of factor VIII and factor IX. However, immune response to the adeno-associated viral vector remains an issue for the majority of patients and therefore alternatives are needed. Nonetheless, she believes that gene therapy will deliver a cure for hemophilia in the near future.
Van den Berg concluded by discussing the underdiagnosis of people with hemophilia in developing countries. Low-dose prophylaxis for children will allow a new generation to survive to adulthood with limited arthropathy, consequently making them ideal candidates for gene therapy.