Efficacy and Safety of rVIII-SingleChain in Surgical Prophylaxis

RVIII-SingleChain is a B-domain-truncated factor VIII construct with a covalent bond between the factor VIII heavy and light chains.

We report on the efficacy and safety of rVIII-SingleChain in subjects with severe haemophilia A undergoing surgery.

Surgery, elective or emergent, was defined as all procedures requiring general, spinal, or regional anaesthesia. rVIII-SingleChain was administered as a bolus or continuous infusion during the perioperative period, dosed individually at the discretion of the investigator based upon the type of surgery and clinical status of the patient. The investigator rated haemostatic efficacy on a 4-point scale (excellent, good, moderate or poor/no response), where treatment success was defined as excellent or good.

Overall, 36 subjects underwent 48 surgeries: 41 surgeries in 30 adult/adolescent (mean age 34 [range 12-64] years) and 7 in 6 paediatric subjects (mean age 8 [5-11] years). rVIII-SingleChain was administered during 24 orthopaedic and 17 non-orthopaedic surgeries in adults/adolescents and 7 non-orthopaedic surgeries in paediatrics. Haemostatic efficacy was rated as excellent (n = 36, 88%) or good (n = 5, 12%) in adult/adolescent surgeries and as excellent (n = 7, 100%) in paediatric surgeries. In adults/adolescents, mean (standard deviation [SD]) blood loss was lower than predicted (68.6 [99.9] mL vs. 196.7 [292.8] mL); values were comparable in paediatric subjects (2.1 [2.7] mL vs. 2.9 [2.7] mL). No serious or related adverse events (AEs) were reported during the perioperative period.

Perioperative administration of rVIII-SingleChain effectively achieves and maintains haemostatic control in adult/adolescent and paediatric subjects with haemophilia A undergoing surgery.