Outcomes in Patients With von Willebrand Disease Receiving Recombinant von Willebrand Factor on Demand and in Surgical Settings: Chart Review.

This European observational chart review assessed the efficacy/safety of recombinant von Willebrand factor (rVWF) for on-demand treatment of spontaneous/traumatic bleeds and prevention and/or treatment of surgery-related bleeding in adults with von Willebrand disease (VWD). Patients (n = 91) were enrolled at first rVWF administration (index). Data were collected for the 12 months before index and until death, loss to follow-up, or end of study (3-12 months after index). Fifteen patients reported an rVWF-treated spontaneous/traumatic bleed at index. Bleed resolution was obtained for 14 patients (unknown status, n = 1), and investigators assessed treatment satisfaction for 13 rVWF prescriptions (2 moderate, 5 good, and 6 excellent). rVWF was used to prevent/treat surgery-related bleeds at index in 76 patients. Bleed resolution was achieved in 25/58 rVWF-treated surgeries; bleed resolution was not applicable for 33 surgeries. In both groups, there were no reports of treatment-emergent adverse events after initiating rVWF, including hypersensitivity reactions, thrombotic events, and VWF inhibitor development. rVWF was shown to be effective for the on-demand treatment of spontaneous/traumatic bleeds, and for the prevention and treatment of surgical bleeds in this real-world VWD population.

Immune Tolerance Induction (ITI) with a pdFVIII/VWF Concentrate (octanate) in 100 Patients in the Observational ITI (ObsITI) Study.

Background Immune tolerance induction (ITI) with repeated factor VIII (FVIII) administration is the only strategy proven to eradicate inhibitors. The observational ITI study is evaluating ITI with a range of FVIII products. Methods This subgroup analysis reports prospective interim data for patients treated with a plasma-derived, von Willebrand factor-stabilized FVIII concentrate (pdFVIII/VWF, octanate). Complete success (CS) of ITI required achievement of three criteria: inhibitor titer < 0.6 BU/mL; FVIII recovery ≥ 66%; FVIII half-life ≥6 hours. Partial success (PS) required achievement of two criteria and partial response (PR) one. ITI success was defined as CS or PS. Data were analyzed for patients who achieved CS, had 36 months' observation, or failed ITI. Results One-hundred prospectively enrolled patients were included in the analysis; 91 had poor prognosis factors for ITI success. The mean (standard deviation) daily ITI dose was 116.4 (61.1) IU FVIII/kg in 14 low responders (< 5 BU/mL) and 173.7 (112.0) IU FVIII/kg in 86 high responders (≥ 5 BU/mL). Inhibitor titers < 0.6 BU/mL were achieved in 71% of patients in a median of 4.01 months, accompanied by a 93% reduction in bleeding rate. ITI success was achieved by 70% of patients and 56 of 72 (78%) primary (first-line) ITI patients. PR was achieved by 5 patients; ITI failed in 25 patients. PS and CS were achieved in a median of 5.55 and 11.25 months, respectively. Conclusions ITI with pdFVIII/VWF led to rapid eradication of FVIII inhibitors, normalization of FVIII pharmacokinetics in the majority of patients, and a significant reduction in bleeding rates.