Low-dose immune tolerance induction therapy in children of Arab descent with severe haemophilia A, high inhibitor titres and poor prognostic factors for immune tolerance induction treatment success

Cost of immune tolerance induction according to its outcome in people with hemophilia A and inhibitors: results from the Co$tIT study

BACKGROUND

Immune Tolerance Induction (ITI) is indicated for people with hemophilia A (PwHA) with inhibitors. It is not known whether the costs differ among ITI outcomes.

AIM

To assess the costs of clotting factor concentrates (CFC) according to ITI outcomes.

METHODS

This retrospective cohort study included 91 PwHA who completed a first course of ITI. We evaluated the costs with CFC 12 months before (pre-ITI), during and 12 months after ITI (post-ITI), according to ITI outcome. We compared costs in each period, between pre- and post-ITI, and evaluated the determinants of costs during ITI.

RESULTS

A total of 32 %, 38 % and 30 % of PwHA achieved complete (CS), partial success (PS), and failed ITI, respectively. The mean cost per PwHA during ITI was US$1.18 million; US$355,838 in CS, US$724,986 in PS, and US$2,653,217 in the failure group. During ITI, approximately 65 % of the variability of the mean cost/kg was explained by the outcome of ITI (failure or PS), duration of ITI, use of prophylactic bypassing agents, and use of incremental FVIII regimen. In post-ITI, we observed about 50 % and 22 % reduction of mean cost/kg in CS and PS, respectively, while failing ITI resulted in increased costs of over 100 % compared with pre-ITI. Regardless of the outcome, in post-ITI, the annualized bleeding rate reduced when compared with pre-ITI.

CONCLUSIONS

Costs with CFC during ITI were the lowest with CS, followed by PS and failure. In comparison with pre-ITI, successful ITI was associated with reduced costs, already noticed in the first year post-ITI.

Intermediate-dose immune tolerance induction outperforms with faster success, less bleeding, and no added cost in comparison with low dose: a multicenter randomized clinical trial

Background

Low-dose (LD) or intermediate-dose (MD) immune tolerance induction (ITI) is effective in children with severe hemophilia A (SHA) with high-titer inhibitors (HTIs) and is attractive in countries with economic constraints. However, high-quality evidence of their use is lacking.

Objectives

This was a multicenter randomized clinical trial comparing the efficacy, safety, and medication cost between LD-ITI and MD-ITI for SHA-HTI children.

Methods

Children with SHA aged <8 years with historical/pre-ITI inhibitor titer 5 to 200 Bethesda Units/mL in 3 centers were randomized 1:1 to receive LD-ITI (recombinant factor VIII [rFVIII] 50 IU/kg every other day) or MD-ITI (rFVIII 100 IU/kg/d) from January 2022 to June 2024 (ChiCTR2200056603, https://www.chictr.org.cn).

Results

Thirty-one patients (16 in MD-ITI and 15 in LD-ITI) were enrolled and followed for >24 months (median, 26.9; range, 24.0-29.5 months). The 2 groups had similar baseline clinical characteristics and similar success rates (93.8% [MD-ITI] vs 86.7% [LD-ITI]). Compared with LD-ITI, MD-ITI patients took a shorter median time to success (4.2 months vs 10.1 months) and partial success (2.7 months vs 6.6 months) and had lower mean rates for all bleeding (0.38/mo vs 1.40/mo) and joint bleeding (0.11/mo vs 0.83/mo). Between the 2 groups, although the MD-ITI group had higher rFVIII consumption (12,775 vs 7680 IU/kg), their total medication costs to success were similar (3626.49 vs 3240.38 US$/kg).

Conclusion

For SHA-HTI children, the success rate and cost for MD-ITI and LD-ITI regimens were similar. MD-ITI regimen would be a priority for regions with economic constraints, considering the shorter time to success, better bleeding control, and no increase in medication cost.

Evaluating the benefits of emicizumab prophylaxis for haemophilia A with inhibitors: A cost-effectiveness and budget impact analysis in Thailand's upper-middle income setting

BACKGROUND

In Thailand, an upper-middle-income country, managing haemophilia A (HA) with inhibitors poses significant challenges, often necessitating bypassing agents (BPAs) for bleeding control. This study evaluates the cost-effectiveness and budget impact of emicizumab, a novel prophylactic agent, as an alternative to both episodic and prophylactic BPA treatments from a societal perspective.

METHODS

A Markov model was employed to estimate the lifetime societal costs and outcomes of emicizumab prophylaxis for HA patients with inhibitors. Treatment efficacy, cost, and epidemiological data were obtained through a comprehensive literature review and incorporated into the model. A 5-year budget impact analysis complemented the cost-utility analysis, with a 3% annual discount rate applied to future costs and outcomes.

RESULTS

In the base-case scenario, emicizumab prophylaxis in HA patients aged 2 years and above demonstrated superior cost-effectiveness, yielding 18.1 quality-adjusted life years (QALYs) per patient over a lifetime and resulting in cost savings of 138 million Thai Baht (THB) compared to BPA prophylaxis. Compared to episodic BPA treatment, emicizumab yielded 30.5 QALYs and saved 25 million THB per patient. The 5-year budget impact was projected at 1775 million THB.

CONCLUSIONS

Emicizumab offers a cost-saving approach for HA treatment with inhibitors in Thailand, promising significant health benefits and budgetary savings. This supports its potential inclusion in Thailand's National List of Essential Medicines to enhance haemophilia care access.

HIGHLIGHTS

Managing haemophilia A (HA) with inhibitors in Thailand, an upper-middle-income country, faces challenges due to limited access to effective treatments or newer drugs for bleeding management. Emicizumab prophylaxis found to as a cost-effective and viable alternative to traditional treatments, effectively preventing bleeding in Thai HA patients over 2 years old with inhibitors. Demonstrating improved clinical outcomes and reduced costs, emicizumab prophylaxis outperforms episodic BPA treatments, positioning it as a superior treatment option for HA patients with inhibitors in Thailand.

Determinants of successful immune tolerance induction in hemophilia A: systematic review and meta-analysis

Background

Immune tolerance induction (ITI) aims to eradicate anti-factor VIII (FVIII) antibodies (inhibitors) in persons with hemophilia A. However, this burdensome treatment fails in 10% to 40%. To estimate the chance of ITI success in clinical decision making, it is important to identify the predictors of ITI success.

Objectives

We performed a systematic review and meta-analysis to summarize the current evidence on determinants of ITI outcome in persons with hemophilia A.

Methods

A literature search was conducted to identify randomized controlled trials, cohort, or case-control studies reporting on the predictors for ITI outcome in persons with hemophilia A. The main outcome was ITI success. Methodological quality was assessed using an adapted Joanna Briggs Institute checklist, rating as high if ≥11 of 13 criteria were met. Pooled odds ratios (ORs) for ITI success were calculated for each determinant. ITI success was defined as negative inhibitor titer (<0.6 BU/mL), FVIII recovery ≥66% of expected, and FVIII half-life ≥6 hours in 16 (59.3%) studies.

Results

We included 27 studies, involving 1,734 participants. Methodological quality of 6 (22.2%) studies (418 participants) was rated as high. Twenty different determinants were assessed. Historical peak titer ≤100 BU/mL (compared with >100 BU/mL, OR, 1.7; 95% CI, 1.4-2.1), pre-ITI titer ≤10 BU/mL (compared with >10 BU/mL, OR, 1.8; 95% CI, 1.4-2.3), and peak titer during ITI ≤100 BU/mL (compared with >100 BU/mL, OR, 2.7; 95% CI, 1.9-3.8) were associated with a higher chance of ITI success.

Conclusion

Our results suggest that determinants related to the inhibitor titer are associated with ITI success.

Correlation Analysis of DNA Methylation in the von Willebrand Factor Promoter Region and the Risk of Unexplained Recurrent Hemophilia: Systematic Review and Meta-Analysis

This study systematically reviewed the effect of DNA methylation in the promoter region of the coagulation factor vWF gene on the risk of unexplained recurrent hemophilia. PubMed, Medline, Web of Science, and other computers were used to search the database, and the statistical randomized controlled trials of coagulation factor vWF in the risk analysis of unknown recurrent hemophilia were collected. The Cochrane systematic evaluation method was used to evaluate the quality of the included kinds of literature, and Revman5 software was used to sort out and analyze the kinds of literature. Meta-analysis showed that there was a statistical difference between the experimental group and the control group in case fatality rate (OR = 1.76, 95% CI (1.29, 2.39), P=0.0003, I² = 0%, Z = 3.58), adverse events (OR = 2.38, 95% CI (1.65, 3.45), P < 0.00001, I² = 0%, Z = 4.60), incidence of joint hemorrhage (OR = 2.52, 95% CI (1.62, 3.91), P < 0.00001, I² = 0%, Z = 4.12), incidence of subcutaneous stasis (OR = 1.76, 95% CI (1.26, 2.45), P=0.0009, I² = 5%, Z = 3.33), and hematoma volume (OR = 1.78, 95% CI (1.32, 2.40), P=0.0001, I² = 23%, Z = 3.80). DNA methylation in the promoter region of the coagulation factor vWF gene was significantly associated with the risk of unexplained recurrent hemophilia. Whether demethylation can improve the bleeding index of patients with recurrent hemophilia remains to be further explored.