Home›Oncology› Low-dose chemotherapy shows no difference in remission but worse outcomes in KIT-mutated AML
Low-dose chemotherapy shows no difference in remission but worse outcomes in KIT-mutated AMLLow-dose chemotherapy shows similar results for some children with leukemia
Cancer medicinePublished October 9, 2026Study authors: Ou Wenxin, Zhu Xiaohua, Lu Jun, Wang Hongsheng, Liao Ning, Liu Yufeng, Jiang Hua, An Qi, Yuan Xiaoju…PubMed ↗DOI ↗Editorial oversight: Dr. Julia Lee, PhD · Oncology, Genomics & Drug Development
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Key Takeaway
Note that while LDC reduces treatment burden, it is associated with significantly worse outcomes in patients with KIT mutations.
This retrospective secondary analysis of a multicenter randomized controlled trial evaluated the impact of low-dose chemotherapy (LDC) compared to standard-dose chemotherapy (SDC) in 221 children with M2 acute myeloid leukemia (AML-M2). The study assessed primary outcomes of complete remission (CR) or CR with incomplete recovery (CRi) and secondary outcomes including 3-year overall survival (OS), relapse-free survival (RFS), and event-free survival (EFS).
In the general study population, LDC showed no significant difference compared to SDC for CR/CRi (67.0% vs 70.5%, p=0.568; 84.4% vs 89.3%, p=0.740). Similarly, 3-year OS (81.2% vs 86.9%, p=0.304), RFS (82.0% vs 88.1%, p=0.205), and EFS (62.1% vs 70.8%, p=0.218) did not differ significantly between the LDC and SDC groups.
However, outcomes differed significantly in patients with KIT mutations. In this subgroup, LDC was associated with worse 3-year OS (67.1% vs 91.5%, p=0.011), RFS (70.6% vs 87.5%, p=0.038), and EFS (49.2% vs 81.0%, p=0.002).
LDC was associated with a lower treatment-related burden, with grade 3-5 events in sepsis occurring in 33.3% of the LDC group compared to 78.8% of the SDC group (p < 0.001). While LDC is a toxicity-sparing strategy, the significantly poorer outcomes in KIT-mutated patients suggest it may not be suitable for this specific subgroup.
How this fits prior evidence
How this fits prior evidence: This finding addresses a gap in identifying specific genetic markers that influence the success of toxicity-sparing strategies in AML. While prior evidence noted that MRG mutations correlate with worse overall survival and lower remission in NPM1-mutated AML, this study identifies KIT mutations as a specific marker where low-dose chemotherapy leads to significantly worse outcomes compared to standard-dose chemotherapy.
Treating childhood leukemia is a delicate balance. Doctors must use strong enough medicine to fight the cancer while protecting the child's body from the harsh side effects of chemotherapy. This study looked at 221 children with a specific type of acute myeloid leukemia to see if a lower-dose chemotherapy approach could reduce the physical toll on young patients.
For most children in the study, the results were very similar regardless of the dose. Both the low-dose and standard-dose groups showed similar rates of complete remission and similar three-year survival rates. The low-dose group also experienced fewer severe complications related to the treatment, such as serious infections, and had a lower overall treatment burden.
However, the researchers found a very important exception. For children whose cancer had a specific genetic marker called a KIT mutation, the lower dose was not as effective. These patients saw significantly lower survival rates and more frequent relapses with the lower dose. This suggests that while low-dose therapy is a helpful way to reduce toxicity for many, doctors must be extra cautious and careful when a KIT mutation is present.
What this means for you:
Low-dose chemotherapy can reduce treatment side effects without hurting outcomes for most children with AML-M2.
Common questions
Is low-dose chemotherapy as effective as standard doses?
For most children with AML-M2, the study found no significant difference in remission rates or three-year survival between low-dose and standard-dose chemotherapy. Both groups showed similar results for primary outcomes like complete remission.
Are there safety benefits to using a lower dose of chemotherapy?
Yes, the low-dose group had a lower treatment-related burden. Specifically, fewer patients in the low-dose group experienced severe grade 3-5 events related to sepsis compared to the standard-dose group.
Are there any risks to the low-dose treatment?
The main risk identified was for patients with a specific genetic marker called a KIT mutation. These patients had significantly worse survival rates and more frequent relapses when treated with the lower dose.
This retrospective secondary analysis of the multicenter randomized CALS III-AML18 trial evaluated the efficacy and safety of low-dose chemotherapy (LDC) compared with standard-dose chemotherapy (SDC) in children with M2 acute myeloid leukemia (AML-M2). A total of 221 children were included, with 109 in the LDC arm and 112 in the SDC arm. The complete remission (CR)/CR with incomplete recovery (CRi) rates after induction I and II were 67.0% versus 70.5% (p = 0.568) and 84.4% versus 89.3% (p = 0.740), respectively. The 3 year overall survival (OS) rates were 81.2% ± 3.9% and 86.9% ± 3.3% in the LDC and SDC arms, respectively (p = 0.304). The corresponding 3 year relapse-free survival (RFS) rates were 82.0% ± 3.8% and 88.1% ± 3.1% (p = 0.205), and the 3 year event-free survival (EFS) rates were 62.1% ± 4.8% and 70.8% ± 4.4% (p = 0.218). Among patients with KIT mutations, outcomes were poorer in the LDC arm than in the SDC arm, including 3 year OS (67.1% ± 8.7% vs. 91.5% ± 4.1%, p = 0.011), RFS (70.6% ± 7.8% vs. 87.5% ± 4.8%, p = 0.038), and EFS (49.2% ± 8.7% vs. 81.0% ± 5.7%, p = 0.002). Among patients who developed sepsis, grade 3-5 events were less frequent in the LDC arm than in the SDC arm (33.3% vs. 78.8%, p < 0.001). LDC was also associated with faster neutrophil and platelet recovery, lower transfusion requirements, and reduced treatment costs during induction. No statistically significant differences in remission or survival outcomes were observed between LDC and SDC, while the LDC regimen showed a lower treatment-related burden. These findings support further evaluation of LDC as a toxicity-sparing induction strategy in selected pediatric patients with AML-M2. The poorer outcomes observed among patients with KIT mutations warrant caution when considering treatment de-intensification in this subgroup.
