Switch to Kovaltry Safe, Effective in Hemophilia A: Real-world Study
No bleeding worsening indicated; patients, caregivers report high treatment satisfaction
Patients with moderate to severe hemophilia A who switched to Kovaltry (octocog alfa) showed no worsening of their annual bleeding rate, according to real-world data from a Phase 4 study.
Adhering to the therapy remained high and patients reported high treatment satisfaction.
Overall, the study “confirms and extends clinical trial results, demonstrating effective protection from bleeds with octocog alfa prophylaxis in a real-world setting, and no safety concerns,” the researchers wrote.
The study, “Efficacy and safety in patients with haemophilia A switching to octocog alfa (BAY 81-8973): Final results of the global real-world study, TAURUS,” was published in the European Journal of Haematology.
Hemophilia A is caused by the lack of factor VIII (FVIII), a blood-clotting protein. Standard therapy relies on intravenous (into-the-vein) injections of FVIII to stop or prevent bleeds. It can be given either on demand or as a preventive (prophylactic).
Kovaltry, developed by Bayer and formerly known as BAY 81-8973, is a recombinant, or man-made, version of FVIII that’s been approved to manage symptoms of hemophilia A in adults and children in Europe, the U.S., and Canada.
Its approvals were supported by data from LEOPOLD trials, including LEOPOLD 1 (NCT01029340), LEOPOLD 2 (NCT01233258), and LEOPOLD Kids (NCT01311648). Data from these Phase 3 trials showed Kovaltry was safe and effective at preventing and controlling bleeds, including those during surgery.
Results of Kovaltry in real-world study
Now, a team of international researchers reported the final results of a Phase 4, open-label, real-world study called TAURUS (NCT02830477).
Funded by Bayer, TAURUS enrolled 318 patients who were followed at 25 hemophilia centers in Asia, Europe, and the U.S. From these, 302 — all boys and men (median age, 23.5) with moderate to severe hemophilia A — were included in the full analysis set and followed for a minimum of a year and up to about two years or until the end of treatment.
All had switched to Kovaltry after being on preventive standard FVIII replacement therapies with other products. At the start of the study (baseline), 124 patients received Kovaltry 2.5 times a week or less, and 178 more than 2.5 times a week.
Across all treatment centers, most remained on the same regimen by the study’s end. A total of 113 patients (91.1%) continued to receive Kovaltry 2.5 times weekly or less (median dose of 55.6 international units per kilogram of body weight, IU/kg), and 163 (91.6%) continued receiving it more than 2.5 times weekly (median dose, 75.1 IU/kg).
Dosing frequency had to be increased in 14% of patients under age 12, and in 7.3% of those 12 and older.
Patients had a mean of 3.4 annual bleeds in the 12 months before switching to Kovaltry. Data from 268 patients followed for a year showed the total annual bleeding (ABR) rate remained stable, at a mean of 3.6. The ABR rate was higher in those given Kovaltry 2.5 times weekly or less compared with those who received it more than 2.5 times weekly (mean of 4.3 vs 3.3).
Kovaltry has high satisfaction levels
Adult patients and parents or caregivers in both regimen groups reported high levels of satisfaction with Kovaltry, as assessed by a hemophilia-specific treatment satisfaction questionnaire (Hemo-SAT). Composed of six domains, the Hemo-SAT total scores range from zero (highest satisfaction) to 100 (highest dissatisfaction).
The questionnaire, conducted more than 300 days after starting treatment, showed adult patients scored a median of 11.0 and parents/caregivers 9.3.
Treatment adherence was evaluated using the self-/parent-reported Validated Haemophilia Regimen Treatment Adherence Scale-Prophylaxis (VERITAS-Pro). Its scores range from 24 to 120 with lower ones signaling higher adherence.
Two years after starting Kovaltry, data from 288 patients showed the VERITAS-Pro score of the overall population was 33 and remained similar at the last assessment (more than 300 days after starting treatment) with a score of 34.
Kovaltry was generally well tolerated with serious treatment-emergent side effects reported in 31 patients (9.9%). These included gastrointestinal disorders (2.2%), infections (1.9%), and injury, poisoning, and procedural complications (1.9%).
Two fatal adverse events were registered. The first was a 59-year old man with osmotic demyelination syndrome wherein myelin — the protective fatty layer that wraps around nerve cells — is destroyed due to an abnormal sudden rise in sodium levels. The second was a 55-year-old man with metastatic pancreatic cancer. Neither case was related to Kovaltry.
These data “highlight that patients with moderate-to-severe hemophilia A who switched from a previous FVIII treatment to octocog alfa, had a smooth transition, with no safety issues and stable bleeding rates. Patients’ treatment satisfaction and treatment adherence also remained unchanged,” the researchers wrote.