Table 3.

Results of multivariate Cox proportional hazards model of OS

Covariate	Primary and secondary MF		Overt PMF		Pre-PMF		Post-PV/ET MF
	HR (95% CI)	P	HR (95% CI)	P	HR (95% CI)	P	HR (95% CI)	P
Constitutional symptoms	NS		NS		NS		NS
Leukocytes >25 × 109/L	4.81 (2.79-8.26)	<.0001	4.58 (1.90-11.01)	.0007	18.28 (4.69-71.21)	<.0001
Hemoglobin <10 g/dL	2.27 (1.48-3.48)	.0002	NS		2.61 (1.01-6.81)	.0487	2.75 (1.54-4.91)	.0006
Blood blasts ≥2%	1.80 (1.10-2.96)	.0204	2.52 (1.17-5.46)	.0186	NS		2.90 (1.56-5.42)	.0008
Platelet count <100 × 109/L	4.79 (2.72-8.44)	<.0001	4.80 (2.09-11.00)	.0002	7.98 (2.33-27.36)	.0010	8.25 (3.45-19.74)	<.0001
BM fibrosis grade ≥2	NS		—		—		—
Absence of CALR1-like	NS		NS		NS		NS
HMRMT*	1.86 (1.24-2.80)	.0029	NS		11.16 (3.53-35.28)	<.0001	NS
≥2 HMRMTs†	NS		NS		NS		NS
RAS/CBLMT	1.73 (1.10-2.71)	.0177	2.91 (1.54-5.50)	.0010	NS		NS
Cytogenetics‡
Favorable	Reference		Reference		Reference		Reference
Unfavorable	NS		2.39 (1.08-5.28)	.0314	NS		NS
Very high risk	4.25 (2.27-7.98)	<.0001	10.82 (3.57-32.76)	<.0001	20.33 (4.58-90.31)	<.0001	NS

NS, not significant.

^*The HMR category is defined as the presence of a mutation in any of the following genes: ASXL1, EZH2, SRSF2, and IDH1/2.

^†≥2 HMR^MTs indicate the presence of 2 or more mutations in the ASXL1, EZH2, SRSF2, and IDH1/2 genes (2 or more mutations in the same gene are counted as 1).

^‡According to the revised cytogenetic risk stratification.²⁴