CO-01 | BLEEDING EVENTS IN MILD HEMOPHILIA A AND VON WILLEBRAND DISEASE TYPE 1 YEARLY TREATABLE WITH DESMOPRESSIN IN ITALY

A. Gringeri^1|2, P.M. Mannucci³, G.C. Castaman⁴, F. Peyvandi^3|5 | ¹Fondazione Charta, Milano, Italy; ²Centro di Sanità Solidale, Lucca, Italy; ³Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Angelo Bianchi Bonomi Hemophilia and Thrombosis Center and Fondazione Luigi Villa, Milano, Italy; ⁴Centre for Bleeding Disorders and Coagulation, Careggi University Hospital, Firenze, Italy; ⁵Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Italy

Background. Subcutaneous and intranasal desmopressin is safe and effective in type 1 VWD and particularly convenient for pediatric use and home treatment. Thus, it can reduce in-hospital admissions and inherent costs and favor adherence and the prompt control of bleeding. Nevertheless, it is often underused or unavailable. We aimed to establish how many patients with mild hemophilia A and VWD type 1 and how many bleeding episodes can potentially benefit from it in Italy.
Methods. The reference population of Italian patients with mild hemophilia A and type 1 VWD was that reported in the National Registry of congenital bleeding disorders. Report 2023 of Istituto Superiore di Sanità (ISS). We reviewed the literature to estimate the bleeding incidence in patients with mild hemophilia A and type 1 VWD. We adopted the rate of responsiveness to desmopressin in VWD type 1 as reported in the meta-analysis of Laan et al. (Blood 2025; 145:1814): 0.89 (confidence interval, CI, 0.83-0.93). The rate of DDAVP responsiveness was estimated to be about 80%.
Results. The ISS Report 2023 gave details on 2,085 patients with hemophilia A, of whom 938 had mild-severity defects, and on 2,422 patients with VWD, of whom 2,069 had type 1. Based on these figures, data on bleeding rates and desmopressin response, we estimated 188 yearly bleeding events in mild hemophilia A and 6,156 in type 1 VWD; of these, 5,840 events are represented by heavy menstrual bleeding in 608 women in fertile age (15-49 years). Overall, mild hemophilia A and VWD type 1 patients would successfully be treated with desmopressin for at least 150 and 4,925 yearly bleeding events, respectively.
Conclusions. More than 5,000 bleeding episodes can benefit from desmopressin treatment. This number of bleeding events is based on the number of patients with type 1 VWD and mild hemophilia A reported in the National Registry of Congenital Bleeding Disorders, which collected data from 71% of Italian hemophilia centers only. Consequently, it can be expected that the number of bleeding episodes treatable with desmopressin might be higher. With a higher availability of intranasal and subcutaneous desmopressin, a huge number of bleeding events in VWD type 1 can be treated successfully, safely, and economically, thus reducing the use of costly replacement therapies. It has been estimated (Gringeri & Castaman: Italian resource use in mild hemophilia A and type 1 von Willebrand disease). 2026: this abstract book) an overall annual expenditure of 29.6 million € for the procurement of 61 million IU FVIII concentrates. These figures include use of desmopressin for diagnosis, surgery, childbirth, and the preemptive use for trauma or bleeding prophylaxis, in addition to the bleeding episodes that we considered.