Alix Arnaud, Director of Health Economic and Value Assessment BP at Sanofi, discusses the effects of caplacizumab combination therapy in patients with acquired thrombotic thrombocytopenic purpura (TTP).
TTP is a rare blood disorder characterized by low platelets, small areas of bleeding under the skin, low red blood cell count, and hemolytic anemia. TTP causes blood clots to form in small blood vessels throughout the body. These clots can impede blood flow to a variety of orgrans, such as the brain, kidneys, and heart. Complications may include neurological problems (such as personality changes, headaches, confusion, and slurred speech), fever, abnormal kidney function, abdominal pain, and cardiac problems. Acquired TTP usually begins in adulthood, but can affect children. An episode of TTP usually occurs suddenly and lasts for days or weeks, but it may continue for months. Relapses (or flareups) can occur in up to 60% of people who have the acquired TTP. Acquired TTP is caused when a person’s body mistakenly makes antibodies that block the activity of the ADAMTS13 enzyme.
Caplacizumab (CPLZ) targets the Willebrand factor, inhibiting the interaction of glycoprotein Ib-IX-V receptors in the platelets. It is approved for the treatment of adults with TTP in combination with plasma exchange (PEX) and immunosuppression (IS).
A literature review was conducted to assess the outcomes of this combination therapy (CPLZ+PEX+IS) in comparison to treatment with plasma exchange and immunosuppression with or without rituximab, in treating TTP.
To ensure comparability, the analysis focused on patients who received frontline CPLZ within 72 hours of PEX initiation, excluding delayed treatment cases. New exacerbation and relapse definitions were adopted to align with evolving treatment standards.
Results
The analysis included 35 publications covering 1,286 CPLZ-treated and 871 control-treated episodes. Due to clinical heterogeneity, random effects models were preferred for pooled estimates. Results demonstrated that CPLZ significantly accelerated platelet count normalization, reducing time to normaliztion by 51% compared to control ( 3.59 vs. 7.36 days). CPLZ also lowered mortality risk, with an estimated number needed to treat 25 patients.
CPLZ shortened hospital stays by 30% (12.31 vs. 17.65 days) and PEX duration by 41% (6.41 vs. 10.92 days). Additionally, it significantly reduced exacerbation rates. While CPLZ was associated with a higher risk of bleeding events, the increase was primarily in minor, manageable cases, with no significant difference in major bleeding risks. Relapse rates at one year did not significantly differ between treatment groups.
These findings reinforce CPLZ’s role in improving key clinical outcomes for TTP patients, highlighting its ability to reduce disease burden while maintaining long-term efficacy.
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To learn more about TTP and other rare hematologic conditions, visit https://checkrare.com/diseases/hematologic-disorders/
