Introduction & Objective:
Standard approaches to prophylaxis may be further improved by taking into account individuals’ pharmacokinetic (PK) profile, thereby increasing the likelihood of therapeutic success [Valentino 2012, Valentino 2014, Lissitckov 2017]. One study demonstrated an association between more time spent above higher FVIII levels (20 and 30%) and lower bleeding rates [Valentino 2016]. Furthermore, a consensus statement proposes to target specific factor levels to tailor treatment for different patient profiles [Iorio 2017]. Additionally, new extended half-life treatments provide physicians with another option to personalize therapy. As more data and therapeutic options become available, it is important to understand physicians’ current perceptions and practice patterns with respect to personalizing haemophilia A care in the US.
Materials & Methods:
Physicians in the US who treat persons with severe hemophilia A and provided informed consent were eligible to complete a cross-sectional, double-blinded web-based survey to evaluate physicians’ perceptions and practice patterns with respect to measuring PK and if/how they personalize FVIII treatment with this information, when and to what extent. This abstract presents results from the first half of the survey which focused on ways in which physicians measure FVIII pharmacokinetics and personalize care.
Results:
Ninety physicians completed the survey. The top three most important considerations for personalizing therapy in general were bleeding history, patient goals, and physical activity. The most commonly cited reason for conducting a PK assessment was product switch (74%) while the most common barrier was patient willingness/availability (60%). Physicians reported using a PK-based approach to personalize treatment in 25% (median) of their severe patients. Of physicians who use PK, trough levels (91%), half-life (58%), peak levels (56%) and Area Under the Curve (22%) were used. While 12% of these physicians reported using all PK parameters, 18% only used trough levels. 23% reported using peak, trough and half-life in combination. Most physicians (89%) indicated using PK data to adjust dose and 50% also used it as a patient education opportunity.
Conclusions:
There was significant variability across respondents as to how PK is assessed and how PK parameters are used in treatment decisions, suggesting an opportunity to increase awareness and use of PK-guided personalization to ultimately improve patient care. Additional education on the definitions and details of PK-guided dosing could help improve overall adoption of this treatment strategy and align the community on what it means to personalize therapy using PK information. More research studying the association between PK-guided prophylaxis and outcomes is encouraged to better understand how best to personalize PK-based prophylaxis for different patient scenarios.