Enhancing Hemophilia A Care Through Home-Based Prophylaxis: Real-World Outcomes of a National Patient Support Program in Mexico

<b>Background/Objectives:</b> Patient Support Programs (PSPs) are increasingly used to support treatment adherence and continuity of care in chronic, high-cost conditions. In hemophilia A, consistent prophylaxis is essential to prevent bleeding episodes and long-term joint damage. In Mexico, disparities in access to treatment have encouraged the development of public-industry collaborative models. The objective of this study was to describe the structure, implementation, and operational characteristics of a PSP delivering home-based prophylactic treatment for individuals with hemophilia A in Mexico, and to compare annual bleeding rates according to factor VIII dosing adequacy. <b>Methods:</b> A cross-sectional, retrospective analysis was conducted using fully anonymized operational data from the PSP registry between January 2023 and March 2024. Variables included infusion location and administrator, prescribed and used doses, weekly infusion frequency, program incorporation and discontinuation, geographic coverage, and bleeding events. Annual bleeding rates were compared across dosing categories using Poisson regression models with patient-years as an offset. <b>Results:</b> A total of 1173 patients contributed 16,331 infusion records. Participants were predominantly male (99.8%), with a median age of 26 years; 71.8% had severe hemophilia. Home infusion accounted for 92.0% of administrations, primarily self-administered or caregiver-delivered. The median prescribed and used monthly doses were 18,000 IU and 16,000 IU, respectively, with dose concordance observed in 66.8% of records. Only 40.7% of patients achieved the recommended prophylactic frequency of three infusions per week. Geographic coverage increased from 62.5% to 71.9% of states. The overall annualized bleeding rate was 2.24 bleeds per patient-year. When stratified by dosing adequacy, patients receiving doses consistent with clinical recommendations showed the lowest bleeding rate (0.18 bleeds per patient-year), compared with those with overdosing (3.84) and underdosing (6.68), with statistically significant differences between groups. Knees, elbows, and ankles were the most frequently affected sites. <b>Conclusions:</b> This PSP achieved broad national reach and high adoption of home-based infusion. The observed dose-dependent differences in bleeding rates underscore the clinical relevance of appropriate prophylactic dosing within structured support programs and support the value of PSPs in strengthening treatment continuity in middle-income settings.