New Treatment Options for Glanzmann’s on the Horizon

Written by Suzy Fisk, March 2, 2022

Last month clinicians and researchers from across the world gathered virtually at EAHAD, a congress on bleeding disorders care and treatment. The Haemophilia Society was there to ensure our members hear about the latest work on new treatments.

Members affected by the rare bleeding disorder Glanzmann’s Thrombasthenia will be very interested to hear that new treatment options may be on the horizon, with two presentations at the Congress addressing possible future treatment options.

In one presentation initial research on a new treatment currently known only as HMB-001 was presented. This is a novel bispecific antibody, which means it is large protein that has been engineered to attached to two specific other proteins or cells in the blood. Bispecific antibodies have been used in other bleeding disorders treatments already, most notably in Emicizumab (Hemlibra) now being used by people with haemophilia A.

The way HMB-001 works is by binding with activated factor VII (factor VIIa) and in doing so extending its half-life (the time it remains circulating in the blood). This allows the body to accumulate factor VIIa, then, when required, HMB-001 also targets activated platelets to promote thrombin generation. This means it works to help clotting in a similar way to how recombinant VIIa (Novoseven) works which is already in use to treat bleeds in people with Glanzmann’s as well as other bleeding disorders.

Glanzmann’s does not currently have any effective prophylactic treatment options instead recombinant factor VIIa or in severe cases platelet transfusions are used to treat acute bleeds. You can read more about Glanzmann’s and its treatment in our factsheet. This new treatment could provide a way to prevent bleeding in people with Glanzmann’s but may also be effective in treating other bleeding disorders too. A phase 1/2 clinical trial is due to start later this year.

In another talk a new potential gene therapy for treating Glanzmann’s was presented. This treatment would use a lentivirus vector to introduce a fully functional gene into cells and then release the cells back into people with Glanzmann’s.  So far it has only been tested in animal models but if it is successful, it could present another novel approach to treating severe genetic platelet disorders.