Higher neutrophil counts are associated with successful tyrosine kinase inhibitor discontinuation in patients with chronic myeloid leukemia

Figures & data

Figure 1. Treatment course of the patient (A). Average white blood cell count (B), neutrophil count (C), and lymphocyte count (D) at the first, second, and third discontinuations of tyrosine kinase inhibitors (before 6 months TKI discontinuation). Abbreviation: MMR, major molecular response.

Table 1. Univariate analysis to identify clinical characteristics responsible for molecular relapse.

Variable	n	Estimated treatment-free remission at 12 months	P-value	Hazard ratio (95% CI)	P-value
		(%, 95% CI)
Age (years)
<60	26	60.2 (38.7–76.3)		1
≥60	27	44.4 (25.6–61.7)	0.257	1.561 (0.716–3.403)	0.263
Sex
Female	22	40.9 (20.9–60.1)		1
Male	31	60.4 (40.9–75.3)	0.225	0.625 (0.290–1.350)	0.232
Sokal risk score
High	7	71.4 (25.8–92.0)		1
Intermediate	16	43.8 (19.8–65.8)		2.455 (0.530–11.390)	0.251
Low	27	50.4 (30.3–67.5)	0.701	1.948 (0.439–8.653)	0.381
Missing	3
BCR-ABL1 transcript at TKI discontinuation
MR^4.0	29	44.8 (26.5–61.6)		1
MR^4.5	13	53.8 (24.8–76.0)		0.711 (0.280–1.803)	0.472
UMRD	22	56.4 (32.8–74.5)	0.446	0.610 (0.271–1.370)	0.231
TKI before discontinuation
Imatinib	10	46.3 (31.0–60.3)		1
Dasatinib	44	50.0 (18.4–75.3)		0.872 (0.355–2.145)	0.766
Nilotinib	10	70.0 (32.9–89.2)	0.428	0.448 (0.112–1.792)	0.256
TKI treatment duration before discontinuation
<56.0 months	26	50.0 (29.9–67.2)		1
≥56.0 months	38	51.1 (34.1–65.8)	0.936	0.972 (0.479–1.969)	0.936
DMR duration
<38.4 months	32	45.7 (27.8–61.8)		1
≥38.4 months	32	55.8 (37.0–71.0)	0.375	0.732 (0.365–1.467)	0.379
TKI discontinuation phase
First	53	52.2 (37.9–64.6)		1
Subsequent	11	43.6 (14.7–69.9)	0.791	1.128 (0.462–2.751)	0.792
White blood cell count at TKI discontinuation
<5150/μL	32	37.5 (21.3–53.7)		1
≥5150/μL	32	64.8 (45.5–78.8)	0.025	0.446 (0.215–0.925)	0.030
Neutrophil count at TKI discontinuation
<2439/μL	32	34.4 (18.8–50.6)		1
≥2439/μL	32	67.8 (48.4–81.2)	0.004	0.348 (0.166–0.737)	0.006
Lymphocyte count at TKI discontinuation
<1978/μL	32	46.9 (29.1–62.8)		1
≥1978/μL	32	55.2 (36.3–70.5)	0.55	0.809 (0.402–1.627)	0.552

Abbreviations: CI, confidence interval; TKI, tyrosine kinase inhibitor; UMRD, undetectable minimal residual disease; DMR, deep molecular response.

Table 2. Multinivariate analysis to identify clinical characteristics responsible for molecular relapse.

Variable	n	Hazard ratio (95% CI)	P-value
Age (years)
<60	26	1
≥60	27	1.749 (0.789–3.879)	0.169
Sex
Female	22	1
Male	31	0.689 (0.318–1.493)	0.345
DMR duration
<38.4 months	32	1
≥38.4 months	32	0.560 (0.245–1.280)	0.169
Neutrophil count
<2439/μL	32	1
≥2439/μL	32	0.325 (0.137–0.772)	0.011

Abbreviation: DMR, deep molecular response; CI, confidence interval.

Figure 2. Average neutrophil count during treatment with tyrosine kinase inhibitors (TKIs) (imatinib, dasatinib, and nilotinib).

Note: Kruskal-Wallis test with Bonferroni correction.