Characteristics of Clinical Response in Patients With Chronic Myeloid Leukemia With an <i>ABL1</i> In‐Frame Exon 4 Deletion: A Multicenter Retrospective Study
Introduction: splicing variant in chronic myeloid leukemia (CML), the clinical significance of which remains unclear. Methods: We retrospectively analyzed seven chronic-phase CML patients with this variant, identified by Sanger sequencing during routine monitoring of atypically slow molecular responses. Results: All patients achieved hematologic responses; molecular responses, although attained, were often delayed. No patient progressed to advanced phase disease during a median follow-up of 39.0 months. Conclusion: Detection of this kinase-inactive variant should not, in itself, be regarded as a definitive resistance mechanism. Larger collaborative studies using quantitative methodologies are needed. Trial Registration: The authors have confirmed clinical trial registration is not needed for this submission.
Authors
- Nobuhiro Kanemura (ORCID: https://orcid.org/0000-0001-8449-9918)
- Yoshikazu Ikoma (ORCID: https://orcid.org/0009-0008-4780-9137)
- Masahito Shimizu (ORCID: https://orcid.org/0000-0002-1151-2058)
- Nobuhiko Nakamura (ORCID: https://orcid.org/0000-0003-1682-7777)
- Yuto Kaneda (ORCID: https://orcid.org/0009-0005-5910-0609)
- Kenji Fukuno
- Senji Kasahara (ORCID: https://orcid.org/0000-0002-1784-2402)
- Yutaka Tsukune (ORCID: https://orcid.org/0000-0002-2414-387X)
- Tomoiku Takaku (ORCID: https://orcid.org/0000-0002-6493-6225)
- Hiroshi Nakamura (ORCID: https://orcid.org/0000-0001-7699-9840)
- Takuro Matsumoto (ORCID: https://orcid.org/0000-0001-5589-8573)
Institutions
- Juntendo University (JP)
- Gifu Municipal Hospital (JP)
- Gifu University Hospital (JP)
- Takayama Red Cross Hospital (JP)
- Kobe University (JP)
- Saitama Medical University (JP)
Publication Details
- Journal
- eJHaem
- Published
- 2026-07-27
- DOI
- https://doi.org/10.1002/jha2.70361
- Primary Topic
- Chronic Myeloid Leukemia Treatments
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- Forskningsrådet om Hälsa, Arbetsliv och Välfärd