aTTP, or acquired thrombotic thrombocytopenia purpura, is an immune condition which results in severe Thrombocytopenia. Thrombocytopenia means the body doesn’t have enough platelets in the blood. In aTTP, it’s caused by blood clots which occur in the small blood vessels in the body. aTTP also causes blood flow to be restricted to some areas of the body, organ damage, and a destruction of red blood cells.
Currently, patients living with aTTP must undergo a daily plasma exchange as well as immunosuppression. But even so, the condition can be life-threatening as this treatment does not fully stop clotting in the small blood vessels. In addition to other complications which stem from the illness, people with aTTP are at a high risk for heart attack and stroke.
But, according to research published in The New England Journal of Medicine, a new therapeutic option may be on its way for aTTP patients. The journal just released positive results from a Phase 3 clinical trial investigating Cablivi (caplacizumab).
This Phase 3 investigation, called HERCULES, was double-blind, randomized, and placebo-controlled. It included 145 individuals diagnosed with aTTP. These patients were all randomly assigned to either receive a placebo or Cablivi in addition to immunosuppression and plasma exchange.
Cablivi already received approval from the European Commission back in August of 2018.
The trial examined Cablivi as a treatment for adults with aTTP. The primary endpoint was time to platelet count response. This endpoint was met with a significant reduction in time. Participants in the trial who received the drug were actually 1.55 times more likely to reach a normal level of platelets.
The secondary endpoint of this trial was also met. It examined thromboembolic events while on treatment with Cablivi. The drug produced a significant reduction in not only recurrence of aTTP (67% reduction) but also death as a result of the disease. Reductions in major thromboembolic events, recurrences, or death, were reduced by 74% in total when patients were receiving Cablivi.
Additionally, those taking Cablivi experienced normalization in organ-damage markers much faster than those taking placebo. These individuals were able to reduce their plasma exchange by 38% and had much shorter ICU and overall hospital stays (reduced by 65% and 31% respectively).
No patients in the trial who were taking Cablivi developed refractory disease. Unfortunately, three individuals taking placebo did. Overall, the safety profile of Cablivi remained the same as what was previously documented for the treatment. The most common AEs reported in the trial were gingival bleeding and epistaxis.
Hopefully, we will see this treatment become available for aTTP patients soon! There is currently an unmet need for this population of patients, but these results are bringing renewed hope to this community.
You can read more about this Phase 3 study and Cablivi here.