{
  "abstract": "Introduction: The management of pediatric patients with hemophilia is associated with high treatment burden due to the frequency of intravenous administration to prophylactically maintain hemostasis. Fitusiran is a subcutaneous (SC) antithrombin (AT)-lowering therapeutic that increases thrombin generation to restore hemostasis in people with hemophilia A or B (PwHA/B), regardless of inhibitor status. The fitusiran clinical program consists of a global, diverse population of 400+ participants aged ≥12 years (yr) from 24 countries. Objectives: To evaluate efficacy and safety during the fitusiran prophylaxis and standard of care (SoC) periods in fitusiran-naïve male participants aged 1–<12 yr with HA/B, with or without inhibitors. Methods: ATLAS-KIDS (NCT07285460) is an open-label, multinational, phase 3 study of fitusiran prophylaxis, enrolling ∼85 males aged 1–<12 yr with HA/B, with or without inhibitors. Participants will be enrolled in one of two arms: (1) fitusiran-naïve participants (n = ∼60); (2) participants rolling over from the ATLAS-PEDS study (n = ∼25). During the treatment period, fitusiran-naïve participants start fitusiran treatment at a dose of 10 mg SC QM. Participants rolling over from ATLAS-PEDS Study will continue receiving the fitusiran dose they were receiving in that study. AT activity levels (target range 15–35%) will be monitored to guide dose adjustments. The primary analysis, including only fitusiran-naïve participants, will be conducted once all these participants have completed Week 60 of the study. Inclusion criteria: Males (age 1–<12 yr) with severe HA/B (FVIII <1%/ FIX ≤2%) with or without inhibitory antibodies; with inhibitors: using bypassing agents (BPA) for ≥3 months; without inhibitors: using clotting factor therapy for ≥3 months, with no recent BPA use and low inhibitor levels (<0.6 BU/mL). Participants with history of SC injections intolerance, or arterial or venous thromboembolism, AT level <60% at screening, liver disease, and known coexisting bleeding/thrombophilic disorder are excluded. Primary endpoint: ABR in the fitusiran primary efficacy (Day [D] 85–421) and SoC periods. Secondary endpoints include annualized spontaneous bleeding rate (AsBR) and annualized joint bleeding rate (AjBR) (D85–421) and SoC period; ABR during fitusiran treatment period for fitusiran-naïve (160 weeks) and rolled-over (60 weeks) participants; change in physical activity, pain intensity, and HRQoL; incidence, severity, and relatedness of adverse events; change in total and domain scores, target joints resolution at D421 per ISTH criteria. Participants in Brazil will be enrolled in Arm 1 (fitusiran-naïve participants), the studies will be conducted at Hemocentro UNICAMP, the Ribeirão Preto Hemophilia Treatment Center (University of São Paulo), and the Clinical Hospital of the University of São Paulo Medical School (HC-FMUSP). These nationally recognized hemophilia referral centers bring together extensive scientific expertise, well-established clinical research infrastructure, and strong operational capabilities, thereby enhancing evidence generation. Conclusions: Subcutaneous therapies, such as fitusiran, can effectively and safely prevent or reduce the frequency of bleeding episodes, reducing treatment burden, improving clinical outcomes and enhancing quality of life in PwHA/B, including those with inhibitors. ATLAS-KIDS is currently ongoing and aims to provide data for fitusiran in the pediatric population.",
  "abstract_shown": true,
  "affiliations": [
    "Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (HCFMUSP), São Paulo, Brazil",
    "Hemocentro de Ribeirão Preto, Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto (HCFMRP), Universidade de São Paulo (USP), Ribeirão Preto, Brazil",
    "Centro de Hematologia e Hemoterapia (Hemocentro), Universidade Estadual de Campinas (UNICAMP), Campinas, Brazil",
    "Sanofi, Canada",
    "Sanofi, United States",
    "Sanofi, China"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 8,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Paula Ribeiro VILLAÇA"
    },
    {
      "affs": [
        1
      ],
      "name": "Luciana Correa OLIVEIRA"
    },
    {
      "affs": [
        2
      ],
      "name": "Margareth Castro OZELO"
    },
    {
      "affs": [
        3
      ],
      "name": "Fadi SHAMMAS"
    },
    {
      "affs": [
        4
      ],
      "name": "Abhimanyu YARRAMANENI"
    },
    {
      "affs": [
        5
      ],
      "name": "Grace LIN"
    },
    {
      "affs": [
        4
      ],
      "name": "Marek DEMISSIE"
    },
    {
      "affs": [
        4
      ],
      "name": "Shariq ALI"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/5h12vkdh2csda.bib",
  "cited_by": 0,
  "doi": "10.1016/j.htct.2026.108037",
  "fulltext_url": "http://www.sciencedirect.com/science/article/pii/S2531137926017840",
  "id": "5h12vkdh2csda",
  "issns": [
    "2531-1379",
    "2531-1387"
  ],
  "landing_url": "https://doi.org/10.1016/j.htct.2026.108037",
  "language": "en",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "lcc",
      "RC633-647.5"
    ],
    [
      "openalex",
      "2720|Hemophilia Treatment and Research"
    ]
  ],
  "openalex": "W7223144560",
  "pdf_url": null,
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-23",
  "publisher": "Elsevier",
  "ris": "https://research.draconitic.com/paper/5h12vkdh2csda.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:26Z",
      "native_id": "17f1adda954648468e497e85a831497a",
      "source": "doaj",
      "url": "https://doi.org/10.1016/j.htct.2026.108037"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "lcc:RC633-647.5",
      "subfield": "endocrinology-metabolism"
    }
  ],
  "title": "PHASE 3 STUDY INVESTIGATING THE EFFICACY AND SAFETY OF FITUSIRAN PROPHYLAXIS IN MALE PARTICIPANTS AGED 1 TO <12 YEARS WITH HEMOPHILIA A/B, WITH OR WITHOUT INHIBITORS: ATLAS-KIDS, A TRIAL IN PROGRESS IN BRAZIL",
  "title_text": "PHASE 3 STUDY INVESTIGATING THE EFFICACY AND SAFETY OF FITUSIRAN PROPHYLAXIS IN MALE PARTICIPANTS AGED 1 TO <12 YEARS WITH HEMOPHILIA A/B, WITH OR WITHOUT INHIBITORS: ATLAS-KIDS, A TRIAL IN PROGRESS IN BRAZIL",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T13:43:18Z",
  "url": "https://research.draconitic.com/paper/5h12vkdh2csda",
  "venue": "Hematology, Transfusion and Cell Therapy",
  "versions": []
}