Scientific Research Question: rVIII-SingleChain is a novel B-domain truncated recombinant factor VIII in which
heavy and light chains are covalently linked, resulting in an increased stability
and a high binding affinity for von Willebrand factor. In clinical trials, rVIII-SingleChain
has been shown to be efficacious for the treatment and prevention of bleeds in patients
with hemophilia A, and to have a favorable safety profile. Data on the use of rVIII-SingleChain
for the treatment of hemophilia A patients in a real-world clinical setting is missing
thus far. Here we summarize our experience when switching adults/adolescents (Bonn
Center) and children (Munich Center) to rVIII-SingleChain.
Methodology: Adults/adolescents from the Bonn Center (n = 11) and children from the Munich Center
(n = 12) with severe hemophilia A were switched to rVIII-SingleChain and their clinical
response and tolerability to rVIII-SingleChain treatment was reported.
Findings: Switching to rVIII-SingleChain proceeded without any problems in both adults/adolescents
and children. rVIII-SingleChain was shown to be effective for prophylaxis and in the
treatment of bleeding episodes. In 91% (10/11) of adult/adolescent patients a reduction
in injection frequency was possible and most patients (73%) were able to reduce or
maintain their weekly factor consumption of rVIII-SingleChain. In children, injection
frequency was maintained in 83% (10/12) of patients and dose reduction has thus far
been initiated in some children (4/12). rVIII-SingleChain was well tolerated; there
were no safety events and no patients developed inhibitors.
Conclusions: Within our two centers, the transition to rVIII-SingleChain was straightforward;
effective bleed control was achieved across all age groups. In adults/adolescents,
rVIII-SingleChain provided the opportunity for reductions in both injection frequency
and dose, thereby reducing treatment burden of patients; whereas in children it offered
the possibility for dose reduction in some patients.
