February 06, 2019
The US Food and Drug Administration (FDA) has approved caplacizumab (Cablivi, Ablynx), the first therapy specifically for adults with acquired thrombotic thrombocytopenic purpura (aTTP), a rare and life-threatening blood clotting disorder.
"Cablivi is the first targeted treatment that inhibits the formation of blood clots. It provides a new treatment option for patients that may reduce recurrences," Richard Pazdur, MD, director of the FDA's Oncology Center of Excellence and acting director of the Office of Hematology and Oncology Products in the FDA's Center for Drug Evaluation and Research, said in a news release.
Caplacizumab is given by injection in combination with plasma exchange and immunosuppressive therapy.
In a clinical efficacy trial, 145 patients with aTTP were randomly assigned to receive caplacizumab or placebo, along with standard plasma exchange and immunosuppressive therapy.
Platelet counts improved faster among patients treated with caplacizumab compared to those who received placebo. Treatment with caplacizumab also resulted in fewer patients with either aTTP-related death and recurrence of aTTP during the treatment period, or at least one treatment-emergent major thrombotic event.
The proportion of patients who experienced a recurrence of aTTP during the overall study period (ie, the drug treatment period plus a 28-day follow-up period after stopping treatment) was statistically significantly lower in the caplacizumab arm compared to the placebo arm (13% vs 38%).
Common side effects with caplacizumab include bleeding of the nose or gums and headache. The prescribing information for the drug includes a warning about the risk for severe bleeding. Healthcare providers should monitor patients closely for bleeding when administering caplacizumab to patients who are also taking anticoagulants, the FDA said.
Caplacizumab had orphan drug designation and priority review.
According to the National Organization for Rare Disorders, the current rate of occurrence of thrombotic thrombocytopenic purpura (TTP) is about 3.7 cases per million people each year. Two thirds of individuals with TTP are women. It usually affects people aged 20 to 50 years.