A new study has found that the von Willebrand factor (VWF)-binding aptamer rondoraptivon pegol increased the half-life of substituted factor VIII (FVIII) as well as endogenous FVIII levels in patients with hemophilia A. The study, published in Blood, also found that the patients tolerated the subcutaneous treatment well.

“Recently, rondoraptivon pegol (previously BT200), a VWF-binding aptamer, was found to increase VWF/FVIII plasma levels in healthy volunteers, an effect that could be beneficial for patients with hereditary bleeding disorders,” the authors wrote. “This trial investigated the pharmacokinetics, effects and safety of rondoraptivon pegol in patients with hemophilia A of any severity.”

The research team assessed 19 patients with mild, moderate, or severe hemophilia A ranging in age from 24 to 62 years. The patients received rondoraptivon pegol subcutaneously at a dose of 3 mg on days 0, 4, and 7, followed by weekly injections of 3 to 9 mg until day 28. Weekly blood sampling was conducted until day 56.

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The main objective was to evaluate the safety of the injections and their effects on FVIII levels. The authors also assessed the pharmacokinetics of the treatment and the half-lives of substituted FVIII products in those patients with severe hemophilia.

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The results showed that rondoraptivon pegol doubled the levels of endogenous FVIII in the plasma of patients with nonsevere hemophilia, and, in those with severe hemophilia, it markedly extended the half-lives of FVIII products.

Furthermore, under rondoraptivon pegol treatment, the final half-life estimates for all of the FVIII concentrates exceeded their half-lives as published in regulatory documents. Finally, the treatment was well tolerated and showed no clinically significant adverse effects.

The authors conclude that rondoraptivon pegol appears to be a promising and effective therapy that could allow patients to reduce the frequency of prophylactic treatment while maintaining adequate trough levels.


Ay C, Kovacevic KD, Kraemmer D, et al. von Willebrand factor-binding aptamer rondoraptivon pegol as treatment for severe and non-severe hemophilia A. Blood. Published online September 15, 2022. doi:10.1182/blood.2022016571