Frontline flumatinib versus imatinib in patients with chronic myeloid leukemia in chronic phase: Results from the China randomized phase III study.

Abstract

7004 Background: Flumatinib (FM), a derivative of imatinib (IM), is a novel BCR-ABL1 tyrosine kinase inhibitor (TKI). The aim of this open-label phase III study was to validate the efficacy and safety of FM in comparison with IM as frontline treatment in Chinese patients with newly diagnosed Philadelphia chromosome–positive chronic myeloid leukemia (CML) in chronic phase (CML-CP). Methods: Randomization was stratified by Sokal score with a 1:1 allocation to each arm. Primary endpoints were major molecular response (MMR = BCR-ABL IS≤0.1%) rates at 6 and 12 months. Molecular responses were assessed at a central laboratory blinded to treatment allocations during the study. Efficacy endpoints were analyzed for the intention-to-treat populations. This study is registered with ClinicalTrials.gov, number NCT02204644. Results: 400 eligible patients were randomized and patient characteristics at baseline were similar in each arm. The full analysis set (FAS) consisted of 393 patients who received FM 600 mg (n = 196) or IM 400 mg (n = 197) tablets once daily. Compared with IM, FM resulted significantly higher induction of MMR rate (%; 95%CI) at 6 month (33.7; 27.06-40.29 vs 18.3; 12.88-23.67; P = 0.0005) and 12 month (48.5; 41.47-55.47 vs 33.0; 26.43-39.56; P = 0.0021) and also at 3 month (8.2; 4.33- 12.00 vs 2.0; 0.06-4.00; P = 0.0058). Significantly more patients in the FM than in the IM arm achieved a complete molecular response (BCR-ABL IS≤0.0032%) at 12 months. Early molecular response (BCR-ABL IS ≤ 10%) at 3 months and early CCyR at 6 months were also significantly higher with FM than IM (82.1; 76.78-87.50 vs 53.3; 46.33-60.27; P < 0.0001 and 60.71; 53.88-67.55 vs 49.75, 42.76, 56.73; P = 0.0332). FM has a safety profile similar to IM. The rates of grade 3/4 TEAEs of FM were similar to IM, 56.57% (112 of 198) vs 41.38% (87 of 196). However, the frequencies of some nonhematological and hematological adverse events were significantly lower in the FM than in the IM arm, such as rash (4.59% vs 12.63%, P = 0.0064) and eyelid edema (0.51 vs 14.65, P < 0.0001); leukopenia (30.61 vs 62.63, P < 0.0001) and neutropenia (30.10 vs 59.60, P < 0.0001). No specific TEAE was identified in each arm. Conclusions: This phase III study met its primary endpoints. Our study results suggest that FM is comparable to IM in its safety and superior in its efficacy profile at 3, 6 and 12 month time points. These results support FM as a frontline treatment option for patients with newly diagnosed CML-CP. Clinical trial information: NCT02204644.