XDH xanthine dehydrogenase

For topiroxostat, febuxostat, allopurinol, oxypurinol: what EMA and FDA publish about paediatric plans, orphan status and pediatric approvals, and how many registered studies take children. Each line is a yes, no or not published fact from the record linked under it; none of it is a forecast.

• FDA pediatric target list: no · XDH is not on the list

  Rule: Target is on FDA's Pediatric Molecular Target List (relevant targets). Source: FDA Pediatric Molecular Target List (Listed as February 2026 on the FDA Pediatric Oncology page; the file served is 9.7.22_the_relevant_molecular_target_list.xlsx, whose Summary of Changes sheet is headed 'SEPTEMBER 2022 UPDATE' (footnote date 2022-09-01)), 2026-11-11
• EU paediatric investigation plan: yes · EMEA-002754-PIP01-19 (allopurinol;verinurad, Treatment of chronic kidney disease): P: decision agreeing on a investigation plan, with or without partial waiver(s) and or deferral(s), 29 Jan 2021; EMEA-001417-PIP01-12-M04 (febuxostat, Prevention of hyperuricaemia): W: decision granting a waiver in all age groups for all conditions or indications, 20 Jul 2018; EMEA-001952-PIP01-16 (lesinurad;allopurinol, Treatment of hyperuricaemia): W: decision granting a waiver in all age groups for all conditions or indications, 9 Sept 2016

  Rule: An EMA PIP decision (agreement, modification or waiver) lists the drug as its active substance, exact name. Source: EMA data download (dated snapshot), 2026-11-11
• EU orphan designation: yes · EU/3/25/3041 positive 25 Mar 2025: Treatment of Marfan syndrome; EU/3/12/1076 positive 6 Dec 2012: Treatment of perinatal asphyxia; EU/3/15/1493 positive 21 May 2015: Treatment of perinatal asphyxia

  Rule: An EU orphan designation lists the drug as its active substance (exact name) or belongs to a medicine that does; withdrawn and expired designations are listed with their status. Source: EMA data download (dated snapshot), 2026-11-11
• Authorised in the EU: yes · Febuxostat Viatris (previously Febuxostat Mylan): authorised since 15 Jun 2017; Adenuric: authorised since 21 Apr 2008; Febuxostat Krka: authorised since 28 Mar 2019; Duzallo: withdrawn since 23 Aug 2018

  Rule: An EMA medicine record lists the drug as its active substance or INN, exact name; national-only authorisations are not in this file. Source: EMA data download (dated snapshot), 2026-11-11
• FDA orphan designation: not published · FDA's orphan designation database turns away automated requests, so this app does not read it; search it by hand at the link

  Rule: Would be: an FDA orphan designation names the drug. Source: FDA orphan designations search
• FDA pediatric oncology approval: no · FDA's table lists no pediatric approval of topiroxostat, febuxostat, allopurinol, oxypurinol

  Rule: FDA's Pediatric Oncology Drug Approvals table names the drug. Source: FDA Pediatric Oncology Drug Approvals (content current as of 2026-03-03), 2026-11-12
• Registered studies open to children: yes · 32 interventional studies of topiroxostat, febuxostat, allopurinol, oxypurinol include patients under 18; 3 are recruiting, not yet recruiting or active

  Rule: The registry's age group includes Child (birth to 17 years), which also counts studies that set no minimum age. Source: ClinicalTrials.gov search, 2026-11-12

Rare pediatric disease voucher. FDA, content current as of 29 Apr 2026: “As of February 3, 2026, enactment of the Consolidated Appropriations Act, 2026, the rare pediatric disease PRV program will sunset after September 30, 2029. FDA may not award any PRVs under this program after September 30, 2029.” Voucher sale prices are not shown here; they appear only as company-reported news. FDA: Rare Pediatric Disease Designation and Priority Review Voucher Programs

Each drug, stage and indication links to its Open Targets record, where the trials and approvals behind it are listed. Salt forms (for example a mesylate) are listed as Open Targets records them, as separate entries.