FDA Approves Caplacizumab-yhdp (Cablivi) as First Pediatric aTTP Therapy

The US Food and Drug Administration (FDA) has approved Sanofi’s caplacizumab-yhdp (Cablivi) for injection to treat pediatric patients ≥ 12 years of age with acquired thrombotic thrombocytopenic purpura (aTTP) in combination with plasma exchange and immunosuppressive therapy.

As described in a January 5, 2026, press release from the Agency, the decision builds upon caplacizumab’s initial 2019 approval for adults with aTTP and is supported by efficacy data from a retrospective chart review study of 30 patients 2-18 years of age showing 80% of patients achieved clinical remission. Of note, the approval makes caplacizumab the first treatment for pediatric aTTP.

Already a rare disorder, aTTP is even more uncommon in children, occurring in about 1 per 10 million children annually. It causes blood clots in the small blood vessels, which can slow or block the flow of blood to parts of the heart, brain, kidneys, and other organs. In this disorder, platelets clump together, leaving fewer platelets in the rest of the body to help with clotting. In addition, red blood cells may break apart, causing anemia.

The FDA approved caplacizumab for adult patients with aTTP in combination with plasma exchange and immunosuppressive therapy on March 18, 2019, based on findings from the multicenter, randomized, double-blind, placebo-controlled HERCULES trial. Among the 145 enrolled patients randomized to caplacizumab-yhdp (n = 72) or placebo (n = 73), time-to-platelet count response was faster in patients treated with caplacizumab-yhdp.

Treatment with caplacizumab-yhdp additionally resulted in a lower number of patients with TTP-related deaths (0 vs 3) and TTP recurrence (3 vs 28) during the treatment period. Further analysis revealed the proportion of patients with a recurrence of TTP in the overall study period, defined as the drug treatment period plus the 28-day follow-up period after drug treatment discontinuation, was lower in the caplacizumab-yhdp group (13% vs 38%; P <.001).

The efficacy of caplacizumab to treat pediatric patients with aTTP was evaluated in a retrospective chart review study of 30 patients 2-18 years of age. Results showed 80% of patients achieved clinical remission, defined as achieving a normal platelet count and having LDH levels < 1.5 times the upper limit of normal for ≥ 30 days. The most common side effects with caplacizumab are nose bleeds, headache, and gingival bleeding.

As described in the release from the FDA, because caplacizumab works by targeting the abnormal blood clotting, it can also cause serious and fatal bleeding, and the risk of bleeding is greater in patients with underlying coagulopathies or who are also taking blood thinning medicines. According to the Agency, patients should stop treatment if clinically significant bleeding occurs and should not take caplacizumab 7 days before elective surgery, dental procedures, or other invasive procedures. In addition, patients should not take caplacizumab if they have had a severe allergic reaction to any of its ingredients.

References

1. US Food and Drug Administration. FDA approves therapy for rare blood disorder in pediatric patients 12 years and older. January 5, 2026. Accessed January 5, 2026. https://www.fda.gov/drugs/news-events-human-drugs/fda-approves-therapy-rare-blood-disorder-pediatric-patients-12-years-and-older

2. US Food and Drug Administration. FDA approved caplacizumab-yhdp. March 18, 2019. Accessed January 5, 2026. https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approved-caplacizumab-yhdp