Table 4.

Spleen volume response rates and symptom response rates following 24 weeks of treatment with JAK inhibitors in late-stage clinical development.

	First-line MF treatment					Prior ruxolitinib exposure
	JAKARTA [34] fedratinib 400 mg QD N = 96	COMFORT-I [26] ruxolitinib 15–20 mg BID N = 155	COMFORT-II [25] ruxolitinib 15–20 mg BID N = 146	PERSIST-1 [27] pacritinib 400 mg QD N = 220	SIMPLIFY-1 [78] momelotinib 200 mg QD N = 214	JAKARTA2 [71] fedratinib 400 mg QD N = 97	PERSIST-2 [83] pacritinib 400 mg N = 210	SYMPLIFY-2 [84] momelotinib 200 mg QD N = 104
Primary kinases inhibited	JAK2/FLT3	JAK1/JAK2	JAK1/JAK2	JAK2/FLT3	JAK1/JAK2	JAK2/FLT3	JAK2/FLT3	JAK1/JAK2
Spleen volume response ratea	37%b	42%	32%	19%	27%	31%	10%c	7%
Symptom response rated	40%	46%	N/Ae	25%f	28%	27%	21%c	26%

EORTC QLQ-C30 European Organisation for Research and Treatment of Cancer Quality-of-Life Questionnaire, MF myelofibrosis, MFSAF MF Symptom Assessment Form, MPN-SAF Myeloproliferative Neoplasm Symptom Assessment Form.

^aProportion of patients who achieved a ≥35% decrease in spleen volume from baseline through week 24.

^bResponse rate at 24 weeks, confirmed 4 weeks later [34]. Unconfirmed response rate at 24 weeks was 47% [24].

^cAmong 62 patients in PERSIST-2 who had previously been treated with ruxolitinib.

^dProportion of patients who experienced a ≥50% decrease in total symptom score per the MFSAF or the MPN-SAF, from baseline through week 24.

^eSymptom changes in COMFORT-II were assessed according to the EORTC QLQ-C30 questionnaire [25].

^fComposite symptom response rate using both the MPN-SAF (original version) and MPN-SAF version 2.0 questionnaires [27].