Patient and caregiver perceptions of a pre-filled diluent syringe (MixPro®)

Prophylactic coagulation factor replacement is increasingly the treatment modality of choice for people with haemophilia (PWH). Currently available recombinant factor products require reconstitution from a lyophilised powder and diluent, and a range of infusion systems is available to assist in this process. This study aimed to understand the properties of a reconstitution/infusion system that are most important to PWH and carers of children with haemophilia (CWH), and to assess two available systems produced by Novo Nordisk for the reconstitution and infusion of activated recombinant factor VII and recombinant factor VIII: the original infusion system and the newer MixPro® system. Both were tested by a group of 67 PWH or carers of CWH who were naïve to them. Participants rated the performance of each system against 18 predefined parameters using the 7-point Likert scale, and ranked the importance of these parameters to the design of an infusion system. They also directly compared the performance of the two systems and provided qualitative feedback. Overall, MixPro® was preferred to the original system by 94% of study participants. This was reflected in the performance scores for individual parameters, with scores in 16/18 parameters being significantly higher for MixPro® (p<0.05) than the original system. Low contamination risk was seen as the most important criterion in the design and choice of an infusion system, with 97% regarding MixPro® as the superior system in this category. The MixPro® system was perceived as being quick, easy to use, convenient and portable. It is hoped that these findings may help guide the future design of infusion systems for PWH.