The new fusion protein therapy is expected to treat clotting disorders

A new clinical study that finds that combining a small protein with a natural coagulation factor can significantly increase the amount of time the coagulation factor can play in the body, science reported.
, people with severe haemophilia (blood does not coagulate properly) are usually injected with clotting factors at home three to four times a week to prevent bleeding. In the study, the new fusion protein reduced the number of injections to once a week.
researchers have developed an experimental fusion protein called BIVV001, which has not been shown to stop haemophilia patients from bleeding in a large-scale clinical trial, but it can prolong the clotting factor, much to the excitement of some researchers.
haemophilia is often referred to as "royal disease" because it afflicted many European ruling families in the 19th and 20th centuries. Haemophilia has two manifestations, type A and type B, which affect more than 1 million men worldwide (a disease linked to the X chromosome is extremely rare in women).
A is one of the more common of these two types and is caused by a genetic mutation that causes the coagulation factor VIII defect. Patients often experience clotting disorders, joint problems, and life-threatening bleeding events. Patients sometimes have more than 30 bleeding events per year unless they receive preventive synthesis factor VIII treatment or inject other proteins that help with clotting.
, a haematologist at the Northwest Blood Center and lead author of the new study, said frequent injections are a huge burden for haemophiliac patients. She and other researchers in the field have been working to reduce this burden.
normal, most VIII factors in the body by the protein VWF to stabilize its state, to protect the clotting factors from decomposition. However, VWF has a limit on the amount of time VIII factors can stay in human memory, limiting its half-life to about 15 hours. When the VIII factor is injected, it is usually locked on the VWF.
Sanofi and Sobi, the co-sponsors of the new study, have developed a fusion protein that contains a small portion of VWF. They hope the fusion protein will be sufficient to stabilize the clotting factor and prevent it from binding to the body's own VWF.
"only a portion of VWF is needed to stabilize the VIII factor and does not require any other remaining proteins." Konkle said.
16 men with haemophilia A and a history of preventive treatment were included in the new I/IIa, Open Label study, which is primarily used to assess the safety and half-life of BIVV001.
were divided into low-dose and high-dose groups. Each patient received a separate recombinant VIII factor injection and then went through a period of at least 3 days of ebbing (i.e., in a cross-designed trial, in the middle of phase 1 and stage 2 treatment, the period during which the experimental drug was not taken or a placebo was taken), and then BIVV001 was injected, followed by 28 days of observation to determine the safety of each dose.
researchers report in the New England Journal of Medicine on September 10 that plasma VIII factor half-lifes in the low-dose and high-dose groups were 9.1 hours and 13.2 hours, respectively, before patients received BIVV001 injections; During the study, no patients developed resistance to FACTOR VIII, and no allergic reactions or related events occurred.
Konkle said a phase III trial of the drug was under way. If it is confirmed that BIVV001 can prevent bleeding in the same way as coagulation factor VIII and reduce the number of injections, the company hopes to submit the data to the U.S. Food and Drug Administration by 2022 and seek approval to sell the drug. (Source: Xu Yue, China Science Journal)
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