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M. Swaminathan et al.
A
Figure 2. Survival of patients with FLT3-ITD+ acute myeloid leukemia treated frontline with quizartinib in combination with azacitidine or low-dose cytarabine. (A) Overall survival. (B) Relapse-free survival. Quiz: quizar- tinib; AZA: azacitidine; LDAC: low-dose cytara- bine; mo: months.
B
AML, CRc was observed in 64% (n=16 patients: 2 CR, 12 CRi, 2 CRp) of the quizartinib/AZA cohort and 29% (n=4 patients: 1 CR, 2 CRi, 1 CRp) in the quizartinib/LDAC cohort (Table 2). The per-protocol response data are shown in Table 3. The median duration of response was 2.5 months (range, 0.1 - 19.4 months) among the patients treated with quizartinib/AZA and 2.4 months (range, 0.5 - 7.2 months) among those treated with quizartinib/LDAC. Six patients (25%) in the quizartinib/AZA cohort and one (7%) in the quizartinib/LDAC cohort received SCT after achieving CRc. Among the three patients previously exposed to FLT3 inhibitors and treated with quizartinib/AZA, two achieved a CRi and one a CRp (prior sorafenib). Similarly, two of seven (29%) such patients treated with quizartinib/LDAC had responses: one achieved a CRi and one had a PR (prior sorafenib). One of the four patients with prior exposure to AZA for AML achieved a CR with quizartinib/AZA.
Survival
At a median follow-up of 55.1 months (range, 0.2 - 65.2 months), 12 (16%) patients remain alive (8 [20%] in the
quizartinib/AZA cohort and 4 [12%] in the quizartinib/LDAC cohort). The median overall survival for all patients treated frontline was 12.4 months. With the caveat that the study was not powered to determine a survival benefit, the median overall survival was longer in patients treated frontline with quizartinib/AZA than in those treated with quizartinib/LDAC (19.2 vs. 8.5 months, respectively; P=0.036) (Figure 2). The median relapse-free survival for all patients treated frontline in this trial was 8 months: it was longer for patients treated with quizar- tinib/AZA compared to those treated with quizartinib/LDAC (10.5 vs. 6.4 months, respectively; P=0.044) (Figure 2). Patients with R/R AML had a median overall survival of 6.2 months, with a trend to longer over- all survival for those treated with quizartinib/AZA (12.8 vs. 4 months, P=0.053). There was no difference in the median relapse-free survival between the two treatment groups (overall, 5.8 months; 5.8 vs. 6.2 months by treat- ment arm, respectively; P=0.804) (Figure 3). We did not find any specific factors that significantly influenced CRc or survival in either the frontline or R/R treatment settings in the two cohorts (Online Supplementary Figures S1 and S2,
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haematologica | 2021; 106(8)