A study published in Thrombosis and Haemostasis found that tailoring prophylactic treatments for patients with hemophilia A based on population pharmacokinetic data may improve patient-relevant outcomes, such as bleeding and quality of life.
Weekly treatment plans were developed for individual patients who were previously on prophylaxis, situational prophylaxis, or on-demand treatment. The plans considered predicted plasma factor activity levels and patient lifestyle. Primary outcomes included annualized joint bleeding rate (AJBR), responses to a hemophilia-specific quality of life questionnaire for adults (Hemo-QoL-A), and factor VIII usage for 12 months before and after implementing the tailored plans.
Thirty-six patients were enrolled in the study, with 16, 10, and 10 patients in the prophylaxis, situational prophylaxis, and on-demand treatment cohorts, respectively. ABJR and Hemo-QoL-A scores were available for 25 patients on the tailored plans. The median (first quartile; third quartile) ABJR significantly decreased from 2.0 (0, 4.0) to 0 (0, 1.6) for patients receiving prophylaxis (P =.003) and from 16.0 (13.0, 25.0) to 2.3 (0, 5.0) for patients receiving on-demand treatment (P =.003), but it did not change for patients receiving situational prophylaxis SP (2.0 [2.0, 13.6] to 3.0 [1.4, 7.2]; P =.183). Hemo-QoL-A score improvement (2 points or greater) was observed in 58% of prophylaxis patients, 50% of situational prophylaxis patients, and 29% of on-demand treatment patients. Factor VIII usage data was available for 23 patients; the median (Q1; Q3) change in factor VIII usage on the tailored plan compared with the previous treatment was 2400 (121; 2586) IU/kg/year (P =.0033) for the prophylaxis group, 1052 (308; 1578) IU/kg/year (P =.0277) for the situational prophylaxis group, and 2086 (1498; 2576) IU/kg/year (P =.0277) for the on-demand treatment group.
Although the authors issued caution based on the small sample sizes, they concluded that “pharmacokinetics-tailored prophylaxis is a suitable option for adult patients with severe hemophilia [that] may improve ABJR and health-related QoL and optimize usage of health care resources.”
1. Stemberger M, Kallenbach F, Schmit E, et al. Impact of adopting population pharmacokinetics for tailoring prophylaxis in haemophilia A patients: a historically controlled observational study [published online January 27, 2019]. Thromb Haemost. doi: 10.1055/s-0039-1677700