Objective:
To analyze real world rFVIIIFc patient characteristics and treatment interval patterns in patients with hemophilia A based on specialty pharmacy dispensing records.
Methods:
A retrospective analysis was conducted using aggregate Specialty Pharmacy Provider (SPP) records from July 2014 through Mar 2015. SPP data included 63 different attributes for each prescription, including trade name, NDC, quantity shipped, prescribed infusion dose, days supplied, and dose frequency. Patients were considered eligible for the analysis if they received at least one shipment of rFVIIIFc for a prophylactic treatment regimen. Patients were excluded from the analysis if they were being treated episodically, for immune tolerance induction, or pharmacy records did not specify a prescribed infusion dose. Patients were categorized according to their age and dosing interval.
Summary:
The analysis included 405 hemophilia A patients that received at least one shipment of rFVIIIFc with a median age of 23 (range: 2-68) and median weight of 70 kg (range: 10-154kg). Eight percent of dispensing records were for patients less than 6 years of age, 29% were between 6 and 17 years of age, and 63% were 18 years or greater. Pharmacy dispensing records represented 179 distinct prescribers across 40 states. Dosing frequency ranged from four times weekly to beyond once-weekly, with every four days as the most common dosing interval, representing 33% of patient records. The median infusion frequency was every four days. Fifty percent of all patients had a dosing frequency of four days or greater. Of the patients receiving rFVIIIFc that had previous rFVIII dispensing records, the most common rFVIII dosing frequency was three times per week. The majority of patients previously on prophylaxis regimen with a rFVIII dosing frequency of three times per week had a decreased number of prophylactic infusions per week on rFVIIIFc; 4% of patients reduced infusion frequency to every 3 days, 44% of patients reduced infusion frequency to twice weekly, 30% of patients reduced infusion frequency to every 4 days, 10% of patients reduced infusion frequency to every 5 days.
Conclusions:
Current SPP dispensing records demonstrate that rFVIIIFc is being used in a broad patient population based on age range and geographical distribution. Patients with hemophilia A in the US may experience reductions in FVIII infusion frequency when they switch to rFVIIIFc, with conversion to an infusion frequency every four days as the most common treatment regimen and the recommended prophylaxis starting dose according to the US Prescribing Information.