Table 2.

BM cellularity, differentials, and FLT3 and C/EBPα mutations for patients treated with quizartinib

Patient	Cellularity, Pre	Blasts, Pre	Myelocytes and neutrophils, Pre	Cellularity, D.29	Blasts, D.29	Myelocytes and neutrophils, D.29	FLT3 allelic ratio, Pre	FLT3 allelic ratio, D.29	C/EBPα mutation
1	70%	15%	25%	70%	7%	43%	0.1	0.2	None
2	95%	84%	8%	40%	0%	83%	4.1	1.6	TAD*
3	80%	86%	5%	60%	29%	36%	0.2	0.1	None
4	40%	71%	11%	ND	3%	83%	0.3	0.2	None
5	90%	80%	2%	50%	2%	51%	4.9	3.8	None
6	90%	87%	8%	80%	1%	55%	0.2	0.2	None
7	90%	87%	6%	90%	2%	75%	16.4	12.9	None
8	90%	89%	1%	60%	24%	20%	4	1.5	None
9	50%	95%	ND	85%	2%	40%	7	13	None
10	60%	92%	3%	80%	4%	73%	3	4	None
11	75%	75%	12%	70%	6%	53%	3.7	1.3	None
12	70%	77%	14%	85%	0%	63%	0.8	1.3	None
13	ND	59%	15%	40%	0%	66%	1.3	1	None
Mean	75%	77%	9%	68%	6%	57%	3.5	3.2
14	90%	85%	7%	90%	59%	9%	0.4	0.3	bZIP

BM core biopsy samples (decalcified, slide mounted, and stained with H&E) were examined by light microscopy to visually estimate cellularity within 2 weeks prior (Pre) and after 4 weeks of continuous therapy (D.29) with quizartinib. BM aspirates (obtained from the same procedure as the core biopsies) were stained with Wright-Giemsa stain and examined by light microscopy. For each specimen, 100 cells were counted and scored by morphology as blasts, myelocytes, metamyelocytes, bands, or neutrophils and are expressed as a percentage of the total. FLT3 allelic ratios were derived from the aspirate specimens. C/EBPα mutation status was determined as described in “DNA isolation and sequencing.” Mean values are shown for patients 1-13.

^*The TAD mutation was detectable only at disease progression after 4 months of quizartinib therapy.