Real-World Data on Hemophilia a Patient Usage of Bay 81-8973 and Bay 94-9027 Stratified By Body Mass Index Categories in the Athndataset
Authors: Chandler Martin , Charlet Jessica , Chrisentery-Singleton Tammuella 
Published: December 2024

The ATHNdataset is sponsored by the American Thrombosis and Hemostasis Network, including 15,304 hemophilia A patients as of the cutoff date, 11/30/2023.

Optimal prophylactic dosing of Hemophilia A patients is vital to assure bleed protection while not trying to waste costly treatment products. Patients with body mass indexes (BMI) in the obese and underweight categories are known to have in vivo Factor VIII recoveries deviating from the standard 2 IU dl-1/IU kg-1. This adds to the complexity of determining ideal prophylactic regimens in a population with already high inter-patient variability.

This retrospective dataset analysis aims to evaluate treatment trends and effectiveness with BAY 81-8973 (Kovaltry®) and BAY 94-9027 (Jivi®) in 4 BMI categories of Hemophilia A patients in a real-world setting.

According to the Centers for Disease Control and Prevention (CDC), patients treated with BAY 81-8973 and BAY 94-9027 in the ATHNdataset, were stratified into 4 categories: underweight (&lt;18.5); healthy weight (18.5-24.9); overweight (25-29.9) and obese (≥30). Data included demographics, bleed rates, treatment frequencies and target joint status. Query dates were between 1/1/2010 and 11/30/2023.

At data cut-off, 742 patients were treated with BAY 81-8973 and 307 with BAY 94-9027, of which, 289 and 237 were treated prophylactically and had BMI data available, respectively.

Patients using BAY 81-8973 had a mean age of 32 years, 97% were male, 71% white and 85% not Hispanic; 75% had severe disease. According to the CDC, 10% were underweight, 29% healthy weight, 28% overweight and 33% obese.

BAY 81-8973 utilization, gradually increased from lowest BMI category to highest, with patients administering in median 1510, in the underweight category, and in median 3950 International Units (IU) per infusion in the obese category. The inverse correlation was true regarding IU utilization per kg of actual body weight. Patients in the underweight category administered in median 41 IU/kg and 37 IU/kg in the obese category.

Total, joint and spontaneous annualized bleed rate (ABR) means were highest in the underweight and healthy weight categories; mean ABRs were 0.70, 0.27 and 0.22 in the underweight category, respectively and 0.81, 0.43 and 0.50 in the healthy weight category, respectively.

BAY 81-8973 was administered ≥3x/week by 48% of patients in the underweight category, 52% in the healthy weight, 59% in the overweight and 55% in the obese category. The remaining patients for each category either used regimens of ≤2x/week or regimens were unknown.

Patients using BAY 94-9027 had a mean age of 35 years, 97% were male, 82% white and 79% not Hispanic; 77% had severe disease.

According to the CDC, 7% were underweight, 37% healthy weight, 33% overweight and 23% obese.

BAY 94-9027 utilization, gradually increased from lowest BMI category to highest, with patients administering a median 2464 IU in the underweight category, and a median 5000 IU per infusion in the obese category. The inverse correlation was true regarding IU utilization per kg of actual body weight. Patients in the underweight category administered in median 49 IU/kg and 45 IU/kg in the obese category.

Total, joint and spontaneous ABR means were highest in the underweight and healthy weight categories; mean ABRs were 0.63, 0.43 and 0.35 in the underweight category, respectively and 0.60, 0.21 and 0.34 in the healthy weight category, respectively.

BAY 94-9027 was administered ≥2x/week by 70% of patients in the underweight category, 75% in the healthy weight, 61% in the overweight and 76% in the obese category. The remaining patients for each category used less frequent regimens such as every 5 or 7 days or regimens were unknown.

Overall, a low number of bleeds were recorded in all BMI categories; however, the underweight and healthy weight patients numerically had the highest ABRs of all, using the highest amount of IU/kg but a smaller percentage infusing at the same frequency than the overweight and obese patients. Knowing that in vivo recovery with Factor VIII tends to be lowest in underweight patients, these data support previous findings that not only patients with high but also those with low BMIs should potentially be dosed according to different body measurements.

These data should be interpreted with caution owing to limitations of real-world studies.