A long term outcomes analysis of severe haemophilia A boys receiving 4 years prophylaxis on the Chinese Haemophilia Individualized escalating low dose Prophylaxis (CHIPS)

Abstract

Background

The Chinese Haemophilia Individualized Prophylaxis Study (CHIPS), which was launched in 2016, reported a significant reduction in haemarthrosis over a one-year study. However, its long-term efficacy requires verification. This paper summarizes the clinical outcomes of 18 severe haemophilia A (SHA) patients who completed one year on the CHIPS and 3 more years of follow-up.

Methods

Clinical follow-up was based on the CHIPS protocol (from July 2018 to July 2021). Escalation was based on index joint bleeding, and serial ultrasound (greyscale and colour Doppler) examinations of the index joints (both sides of the ankles, knees and elbows) were conducted every 6 months via a scoring system.

Results

A total of 18 SHA patients completed the 3-year study. Fifteen patients dropped out due to the financial crisis during the COVID-19 pandemic in China. The median age was 5.4 (range 4.3–6.9) years. A significant reduction in haemarthrosis was achieved, with mean annual bleeding rates reduced from 18.9 ± 2.8 to 1.7 ± 0.4 (p < 0.001), annual joint bleeding rates from 3.1 ± 0.7 to1.2 ± 0.3 (p < 0.028). 5 out of 8 target joint resolved. Sixteen doses were escalated. At study exit, the heterogeneous treatment outcomes of the SHA boys were 5 at step 4 (20–25 lU/kg, every other day), 10 at step 3 (15–20 IU/kg, 3×/week), 2 at step 2 (10–15 lU/kg, 3×/week) and 1 at step 1 (10–15 lU/kg, 2×/week). The mean FVIII consumption was 2964 IU/kg/year, with savings. The quality of life improved, with Canadian Haemophilia Outcomes-Kids Life Assessment Tool (CHO-KLAT, Chinese Version 2.0) scores ranging from 68.8 to 78.8. There was no change in the ultrasound score.

Conclusion

Our follow-up data on the 18 SHA boys after completing one year on the CHIPS verify the long-term efficacy of the CHIPS for haemarthrosis reduction, joint health preservation, improvement in the quality of life of the boys and cost savings.