{"filing":{"accession_number":"0001501697-26-000072","cik":"0001501697","ticker":"XFOR","company_name":"X4 Pharmaceuticals, Inc","form":"8-K","filing_date":"2026-09-08","report_date":"2026-09-08","primary_document":"xfor-20260908.htm","primary_document_url":"https://www.sec.gov/Archives/edgar/data/1501697/000150169726000072/xfor-20260908.htm"},"events":[{"id":31780,"run_id":29179,"accession_number":"0001501697-26-000072","anchor_item_number":"8.01","event_type":"operational_other","event_domain":"operational","is_material":true,"confidence":0.75,"summary":"X4 Pharmaceuticals announced a positive outcome from an FDA Type C Meeting regarding the 4WARD Phase 3 clinical trial for mavorixafor in chronic neutropenia. The FDA agreed to reduce the trial's sample size from 176 to 126 participants while maintaining statistical power for co-primary endpoints, and approved the proposed safety database for a potential supplemental new drug application. This is a material regulatory milestone affecting the clinical development pathway and timeline (enrollment expected by end-2026, topline data in H1 2028) for a key product candidate, making it a significant operational/strategic event for the company's pipeline, though it does not fit neatly into the specific event categories (not a restatement, impairment, covenant breach, or other defined type).","company_name":"X4 Pharmaceuticals, Inc","ticker":"XFOR","filing_date":"2026-09-08","form":"8-K","submitted_at":null,"items":[{"id":34762,"accession_number":"0001501697-26-000072","item_number":"8.01","item_title":null,"event_type":"operational_other","event_domain":"operational","is_material":true,"confidence":0.75,"reasoning":"X4 Pharmaceuticals announced a positive outcome from an FDA Type C Meeting regarding the 4WARD Phase 3 clinical trial for mavorixafor in chronic neutropenia. The FDA agreed to reduce the trial's sample size from 176 to 126 participants while maintaining statistical power for co-primary endpoints, and approved the proposed safety database for a potential supplemental new drug application. This is a material regulatory milestone affecting the clinical development pathway and timeline (enrollment expected by end-2026, topline data in H1 2028) for a key product candidate, making it a significant operational/strategic event for the company's pipeline, though it does not fit neatly into the specific event categories (not a restatement, impairment, covenant breach, or other defined type).","classifier_version":"claude-haiku-4-5-20251001+prompt-a85dd512","taxonomy_version":"v1.3","classified_at":"2026-09-08T11:16:38.948427+00:00","company_name":"","ticker":null,"filing_date":""}]}],"classifications":[{"id":34762,"accession_number":"0001501697-26-000072","item_number":"8.01","item_title":null,"event_type":"operational_other","event_domain":"operational","is_material":true,"confidence":0.75,"reasoning":"X4 Pharmaceuticals announced a positive outcome from an FDA Type C Meeting regarding the 4WARD Phase 3 clinical trial for mavorixafor in chronic neutropenia. The FDA agreed to reduce the trial's sample size from 176 to 126 participants while maintaining statistical power for co-primary endpoints, and approved the proposed safety database for a potential supplemental new drug application. This is a material regulatory milestone affecting the clinical development pathway and timeline (enrollment expected by end-2026, topline data in H1 2028) for a key product candidate, making it a significant operational/strategic event for the company's pipeline, though it does not fit neatly into the specific event categories (not a restatement, impairment, covenant breach, or other defined type).","classifier_version":"claude-haiku-4-5-20251001+prompt-a85dd512","taxonomy_version":"v1.3","classified_at":"2026-09-08T11:16:38.948427+00:00","company_name":"X4 Pharmaceuticals, Inc","ticker":"XFOR","filing_date":"2026-09-08"}]}