The percentage of subjects who became transfusion independent for ≥ 12 weeks at any time on study. A subject was considered transfusion independent on study if no RBC transfusion occurred in any 12-week period during the 24-week treatment period.

Assessed in the Safety Analysis Set, which includes all subjects who received ≥ 1 dose of momelotinib. Note that 6 subjects discontinued prior to Week 12 and could not be evaluated over the minimum period required for assessment of the endpoint (12 weeks).

The percentage of subjects who became transfusion independent for ≥ 8 weeks, defined as no RBC transfusions for at least an 8-week period at any time on study.

Assessed in the Safety Analysis Set, which includes all subjects who received ≥ 1 dose of momelotinib. Note that 3 subjects discontinued prior to Week 8 and could not be evaluated over the minimum period required for assessment of the endpoint (8 weeks).

The percentage of subjects who achieved a ≥ 35% reduction in spleen volume from baseline as measured by MRI at Week 24.

Assessed in the Safety Analysis Set, which includes all subjects who received ≥ 1 dose of momelotinib. Note that spleen volume at Week 24 was not available for 15 subjects.

The percentage of subjects achieving a ≥ 50% reduction from baseline in TSS at Week 24, as measured by the modified Myeloproliferative Neoplasm Symptom Assessment Form Total Symptom Score (MPNSAF TSS) diary. Total symptom score was assessed using the modified MPN-SAF TSS Version 2, an 8-item questionnaire developed to assess symptom burden and quality of life in patients with MPN. The modified MPN-SAF TSS contained 8 questions, 7 of which were summed to generate the score (the included questions related to tiredness, early satiety, abdominal discomfort, night sweats, itching, bone pain, and pain under the ribs on the left side). Each question is scored on a scale of 0-10, where higher numbers indicate more severe symptoms. For this study, the TSS scale ranges from 0 to 70. The questionnaire was completed daily on an electronic diary device.

There were 3 subjects with missing TSS at baseline who were excluded from the analysis. Note that of the 38 subjects evaluated, 17 were missing Week 24 TSS assessments.

Hepcidin daily change (in nM) was calculated as the predose value subtracted from the 6 hours postdose value at each study visit. Daily hepcidin change at the baseline visit was the difference between 2 values obtained 6 hours apart. No momelotinib was administered on that day.

Median hepcidin at trough was assessed predose at each study visit.

Percent change from baseline in serum iron, where the baseline value is defined as the last value from the baseline period prior to or on the date of first dose of momelotinib administration (Baseline visit).

Percent change from baseline in hemoglobin, where the baseline value is defined as the last value from the baseline period prior to or on the date of first dose of momelotinib administration (Baseline visit).

Percent change from baseline in total iron binding capacity, where the baseline value is defined as the last value from the baseline period prior to or on the date of first dose of momelotinib administration (Baseline visit).

Percent change from baseline in reticulocytes, where the baseline value is defined as the last value from the baseline period prior to or on the date of first dose of momelotinib administration (Baseline visit).

Percent change from baseline in reticulocytes/erythrocytes%, where the baseline value is defined as the last value from the baseline period prior to or on the date of first dose of momelotinib administration (Baseline visit).

Percent change in erythropoietin at Weeks 8 and 20. The baseline erythropoietin value is defined as the last value from the baseline period prior to or on the date of first dose of momelotinib administration (Baseline visit).

Percent change from baseline in erythrocytes, where the baseline value is defined as the last value from the baseline period prior to or on the date of first dose of momelotinib administration (Baseline visit).

Percent change from baseline in hematocrit, where the baseline value is defined as the last value from the baseline period prior to or on the date of first dose of momelotinib administration (Baseline visit).

Percent change from baseline in ferritin, where the baseline value is defined as the last value from the baseline period prior to or on the date of first dose of momelotinib administration (Baseline visit).

Percent change from baseline in soluble transferrin receptor, where the baseline value is defined as the last value from the baseline period prior to or on the date of first dose of momelotinib administration (Baseline visit).

Percent change from baseline in transferrin saturation, where the baseline value is defined as the last value from the baseline period prior to or on the date of first dose of momelotinib administration (Baseline visit).

Percent change from baseline in unsaturated iron binding capacity, where the baseline value is defined as the last value from the baseline period prior to or on the date of first dose of momelotinib administration (Baseline visit).

Percent change from baseline in platelets, where the baseline value is defined as the last value from the baseline period prior to or on the date of first dose of momelotinib administration (Baseline visit).

Percent change from baseline in leukocytes, where the baseline value is defined as the last value from the baseline period prior to or on the date of first dose of momelotinib administration (Baseline visit).

Change from baseline in % blasts at Weeks 2 and 4. The baseline % blasts value is defined as the last value from the baseline period prior to or on the date of first dose of momelotinib administration (Baseline visit).

Percent change from baseline in liver iron content assessed by MRI. The baseline value is defined as the last value from the baseline period prior to or on the date of first dose of momelotinib administration (Baseline visit).

Percent change in %pSTAT stimulated CD3+/4+ T cell at Day 1 (postdose), Week 4 and Week 24. The baseline value is defined as the last predose value from the baseline period prior to or on the date of first dose of momelotinib administration (Day 1 predose).

Percent change in %pSTAT/%tSTAT Stimulated CD3+/4+ T cell ratio at Day 1 (postdose), Week 4 and Week 24. The baseline value is defined as the last predose value from the baseline period prior to or on the date of first dose of momelotinib administration (Day 1 predose).

Percent change in C-reactive protein at Weeks 2, 12 and 24. The baseline C-reactive protein value is defined as the last value from the baseline period prior to or on the date of first dose of momelotinib administration (Baseline visit).