A study stated that a novel treatment which mimics a clotting enzyme was effective, safe, and could eliminate the requirement of blood products for people with thrombotic thrombocytopenic purpura (TTP). The study was published in Blood, the Journal of the American Society of Hematology (ASH).
In congenital TTP, the blood coagulates in small blood vessels throughout the body which may lead to the development of strokes, heart attacks, or kidney damage. Plasma infusion is the most common treatment for TTP, in which people with severe cases of the disease receive the blood product from a donor to restore the missing enzyme in the blood. Many patients develop intolerance to plasma which causes severe allergic reactions among them. Thus, the treatment becomes nearly impossible for them, or they can receive treatment under the very close supervision and with precautions.
Bruce Ewenstein, said, "Today, TTP patients are under-treated because of the complications associated with blood plasma infusions, which has remained the standard treatment for at least half a century. Plasma as a source of enzyme replacement is a sledgehammer approach to treatment, but it is the best we have right now." The new therapy was safe, more convenient, and showed better results.
The plasma levels of an ADAMTS-13 enzyme (which prevent excessive blood coagulation in small blood vessels throughout the body) were found to be very less or absent among patients with TTP which cause platelet clumping and leads to organ damage. To replenish the missing enzyme in the blood, the scientists had produced an engineered form of ADAMTS-13, i.e., BAX 930, without the prospective complications. Patients could eventually be able to administer their infusions at home about every two weeks.
The investigators in Phase I, multi-center clinical trial, examined the safety, tolerability, and pharmacokinetics of BAX 930 among patients (n=15) who lack ADAMTS-13 enzyme. A single dose of BAX 930 was given to each patient and found that it behaved similarly to the endogenous enzyme and restored ADAMTS-13 activity. The researchers observed the normalization of the structure of von Willebrand factor (a blood protein that works closely with ADAMTS-13 to help regulate platelet function and clotting) and also found that platelet count was increased. All 15 patients have tolerated the engineered enzyme without allergic reactions or serious adverse events, and no signs of an immune response to the single infusion.
Marie Scully said, "What the study shows is that this recombinant protein mimics what we would expect the normal protein to do in patients who do not have congenital TTP." He added that the therapy was found to be effective for individuals with TTP and it helped clinicians to give the right treatment to the patients that reduced episodes.