In Finland, all children with severe haemophilia are treated according to a single protocol, whether it’s delivered as part of comprehensive care or in a treatment centre. Outcomes can therefore be meaningfully compared for the entire haemophilia population – even if, in the case of a small country like Finland, that’s not many people.
Specialists from five centres have now reported long term outcomes for 62 children with severe haemophilia born between 1994 and 2013 who had at least 75 exposure days (EDs) to factor concentrate or who developed inhibitors (Haemophilia 2018; DOI: 10.1111/hae.13447). Median follow-up was 12.7 years.
Eighty percent of children received primary prophylaxis with a median infusion frequency of three times weekly. The median age for starting home treatment was 1.1 years. About one-fifth of children developed an inhibitor and this was high titre in 16%. Trough levels were used to guide dosage in only one-fifth of patients but this was associated with a 16% reduction in treatment costs.
The annualised bleeding rate was 0.19 overall (0.16 in non-inhibitor patients, 0.49 with inhibitors). The annual rates of joint bleeds were 0.06, 0.06 and 0.15 respectively. Thirty to forty percent of patients had no joint bleeds (no significant difference by inhibitor status) but 26% of patients without inhibitors and 38% with inhibitors had three or more joint bleeds. Target joints were more common in patients with no inhibitors (16% vs 8% without).
Mean annual treatment costs were 2.8 times greater in patients with inhibitors. Immune tolerance induction (ITI) was completely successful in about one-third of patients with inhibitors and partially so in the remainder. The use of bypassing agents increased monthly treatment costs 5-fold, making ITI cost-neutral after only 2 years.
The authors believe their study is ‘the first of its kind using real-world data to examine the long-term clinical and economic outcomes of regular prophylactic treatment of previously untreated patients with severe haemophilia A’, adding that their findings will be invaluable when they come to evaluate the potential costs of extended half-life factor concentrates.