E S Mullins1, O Stasyshyn2, M T Alvarez-Román3, D Osman4, R Liesner5, W Engl6, M Sharkhawy6, B E Abbuehl6. 1. Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA. 2. SI Institute of Blood Pathology and Transfusion Medicine of NAMSU, Lviv, Ukraine. 3. Hospital Universitario La Paz, Madrid, Spain. 4. Hospital Tengku Ampuan Rahimah, Klang, Selangor, Malaysia. 5. Great Ormond Street Hospital for Children, London, UK. 6. Baxalta Innovations GmbH, now part of Shire, Vienna, Austria.
Abstract
INTRODUCTION: Primary factor VIII (FVIII) prophylaxis is the optimal treatment in children with severe haemophilia A. They are expected to benefit from extended half-life (T1/2 ) FVIII coverage by reduced infusion frequency while maintaining haemostatic efficacy. AIMS: To determine immunogenicity, pharmacokinetics (PK), efficacy, safety and quality of life of prophylaxis with a polyethylene glycol (peg)-ylated FVIII (BAX 855) based on full-length recombinant FVIII (ADVATE) in paediatric previously treated patients (PTPs) with severe haemophilia A. METHODS: PTPs <12 years without history of FVIII inhibitors received twice-weekly infusions of 50 ± 10 IU kg-1 BAX 855 for ≥50 exposure days. Prophylactic dose increases to ≤80 IU kg-1 were allowed under predefined conditions. PK was evaluated after single infusions of 60 ± 5 IU kg-1 . RESULTS: T1/2 and mean residence time were extended 1.3- to 1.5-fold compared to ADVATE (n = 31), depending on the analysis used. The point estimate for the mean annualized bleeding rate in 66 subjects receiving a median of 1.9 weekly infusions of 51.3 IU kg-1 of BAX 855 each was 3.04 (median 2.0); 1.10 (median 0) for joint and 1.16 (median 0) for spontaneous bleeds. Overall, 38% of subjects had zero bleeds. No bleeds were severe. Haemostatic efficacy was rated excellent or good for 90% of bleeds; 91% were treated with one or two infusions. In 8/14 subjects all target joints resolved. No subject developed FVIII inhibitors or persistent binding antibodies that affected safety or efficacy. No adverse reactions occurred. CONCLUSION: Twice-weekly prophylaxis with BAX 855 was safe and efficacious in paediatric PTPs with severe haemophilia A.
INTRODUCTION: Primary factor VIII (FVIII) prophylaxis is the optimal treatment in children with severe haemophilia A. They are expected to benefit from extended half-life (T1/2 ) FVIII coverage by reduced infusion frequency while maintaining haemostatic efficacy. AIMS: To determine immunogenicity, pharmacokinetics (PK), efficacy, safety and quality of life of prophylaxis with a polyethylene glycol (peg)-ylated FVIII (BAX 855) based on full-length recombinant FVIII (ADVATE) in paediatric previously treated patients (PTPs) with severe haemophilia A. METHODS: PTPs <12 years without history of FVIII inhibitors received twice-weekly infusions of 50 ± 10 IU kg-1 BAX 855 for ≥50 exposure days. Prophylactic dose increases to ≤80 IU kg-1 were allowed under predefined conditions. PK was evaluated after single infusions of 60 ± 5 IU kg-1 . RESULTS: T1/2 and mean residence time were extended 1.3- to 1.5-fold compared to ADVATE (n = 31), depending on the analysis used. The point estimate for the mean annualized bleeding rate in 66 subjects receiving a median of 1.9 weekly infusions of 51.3 IU kg-1 of BAX 855 each was 3.04 (median 2.0); 1.10 (median 0) for joint and 1.16 (median 0) for spontaneous bleeds. Overall, 38% of subjects had zero bleeds. No bleeds were severe. Haemostatic efficacy was rated excellent or good for 90% of bleeds; 91% were treated with one or two infusions. In 8/14 subjects all target joints resolved. No subject developed FVIII inhibitors or persistent binding antibodies that affected safety or efficacy. No adverse reactions occurred. CONCLUSION: Twice-weekly prophylaxis with BAX 855 was safe and efficacious in paediatric PTPs with severe haemophilia A.
Authors: Robert Klamroth; Jerzy Windyga; Vlad Radulescu; Peter W Collins; Oleksandra Stasyshyn; Hishamshah Mohd Ibrahim; Werner Engl; Srilatha D Tangada; William Savage; Bruce Ewenstein Journal: Blood Date: 2021-04-01 Impact factor: 22.113