Department of Hematology and Oncology, University Hospital Mannheim, Heidelberg University, Mannheim, Germany.
Munich Leukemia Laboratory, Munich, Germany.
Blood Adv. 2020 Feb 11;4(3):440-443. doi: 10.1182/bloodadvances.2019001111.
FIP1L1-PDGFRA-positive myeloid/lymphoid neoplasms with eosinophilia (MLN-eo) are exquisitely sensitive to imatinib. Almost all patients achieve a complete molecular remission (CMR) by nested reverse transcription polymerase chain reaction, which can be maintained with low-dose imatinib (eg, 3 × 100 mg/wk). Because imatinib can be safely stopped in a substantial proportion of patients with BCR-ABL1-positive CML, we sought to analyze the clinical and molecular follow-up of 12 FIP1L1-PDGFRA-positive patients with MLN-eo in chronic phase who discontinued imatinib after achievement of a CMR. Median time of treatment and median time of CMR before imatinib discontinuation (last dose at 3 × 100 mg/wk, n = 8; or 100 mg/d, n = 4) were 80 (range, 43-175) and 66 (range, 37-174) months, respectively. A molecular relapse was observed in 4 patients after 10, 22 (n = 2), and 24 months. A second CMR was achieved in 3 patients after 3, 4, and 21 months. Eight patients (62%) are in ongoing CMR (median, 17 months; range, 3-71 months). Molecular relapse-free survival was 91% at 12 months and 65% at 24 months. No significant differences (eg, dose and duration of imatinib treatment or duration of CMR before imatinib discontinuation) were identified between patients with and without molecular relapse. Our data demonstrate that imatinib can be safely stopped in FIP1L1-PDGFRA-positive MLN-eo because of a high treatment-free remission at 12 and 24 months and because most patients achieve a rapid second CMR after restart of imatinib.
FIP1L1-PDGFRA 阳性髓系/淋系嗜酸细胞增多性肿瘤（MLN-eo）对伊马替尼高度敏感。几乎所有患者通过巢式逆转录聚合酶链反应（nested reverse transcription polymerase chain reaction）达到完全分子缓解（CMR），并可以用低剂量伊马替尼（例如，3×100mg/周）维持。由于伊马替尼可以安全地用于相当一部分 BCR-ABL1 阳性慢性髓系白血病（CML）患者，因此我们试图分析 12 例 FIP1L1-PDGFRA 阳性 MLN-eo 慢性期患者在达到 CMR 后停止伊马替尼治疗的临床和分子随访结果。中位治疗时间和停止伊马替尼前的 CMR 中位时间（最后一剂伊马替尼剂量为 3×100mg/周，n=8；或 100mg/d，n=4）分别为 80（范围，43-175）和 66（范围，37-174）个月。4 例患者在 10、22（n=2）和 24 个月时出现分子复发。3 例患者在 3、4 和 21 个月后再次达到 CMR。8 例患者（62%）处于持续 CMR（中位时间，17 个月；范围，3-71 个月）。12 个月时无分子复发的存活率为 91%，24 个月时为 65%。无分子复发患者和有分子复发患者之间未发现（例如，伊马替尼治疗的剂量和时间或停止伊马替尼前的 CMR 时间）有显著差异。我们的数据表明，FIP1L1-PDGFRA 阳性 MLN-eo 可以安全地停止使用伊马替尼，因为在 12 个月和 24 个月时有很高的无治疗缓解率，并且大多数患者在重新开始伊马替尼治疗后很快达到第二次 CMR。
