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Alternative Dosing Strategy of Ruxolitinib in Patients With Myelofibrosis

An Open-label Assessment of an Alternative Dosing Strategy of Ruxolitinib in Patients With Primary Myelofibrosis, Post-polycythemia Vera Myelofibrosis, and Post-essential Thrombocythemia Myelofibrosis

Status
Completed
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT01445769
Enrollment
45
Registered
2011-10-04
Start date
2011-09-30
Completion date
2013-04-30
Last updated
2019-03-27

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Post-Essential Thrombocythemia Myelofibrosis, Post-Polycythemia Vera Myelofibrosis, Primary Myelofibrosis

Keywords

Myelofibrosis, Primary Myelofibrosis, PMF, Post-Polycythemia Vera Myelofibrosis, PPV-MF, Post-Essential Thrombocythemia Myelofibrosis, PET-MF, Open label, Ruxolitinib, 18424, Jak inhibitor

Brief summary

The purpose of this study was to evaluate the effect of an alternative dosing strategy of ruxolitinib in subjects with primary myelofibrosis (PMF), post-polycythemia vera-myelofibrosis (PPV-MF) and post essential thrombocythemia-myelofibrosis (PET-MF) in order to minimize the development of anemia and thrombocytopenia.

Detailed description

This pilot study was designed to explore an alternative dosing approach with the purpose of reducing anemia and thrombocytopenia. Subjects began dosing at 10 mg bid and had the opportunity for dose increases based on assessments of efficacy and overall hematologic status in a defined prior dosing interval. Dose increases were restricted to those patients who did not meet criteria for or have a dose hold over the prior 6 weeks, had a platelet count ≥100 x 10\^9/L at week 12 or ≥150 x 10\^9/L at week 18, and had a self-reported Patient's Global Impression of Change (PGIC) score of 3 (minimally improved) to 7 (very much worse) OR the subject's palpable spleen length below the costal margin had been reduced by less than 40% at that visit relative to Baseline. Dose increases were elective and not required. Subjects were permitted a dose increase of 5 mg BID to 15 mg BID at Week 12 and to a maximum of 20 mg BID at Week 18. There were also protocol-required dose decreases for thrombocytopenia (platelets \<100 x 10\^9/L) or protocol-defined anemia (decline in hemoglobin of at least 2 g/dL to a level \< 8 g/dL, development of transfusion dependence, or a 50% increase in transfusion requirements for transfusion dependent subjects).This approach assumed that beginning at a low dose for initial therapy might have a positive impact on the rate of the initial hemoglobin decline and the nadir by decreasing the level of JAK-mediated inhibition of hematopoiesis. Specific dose modifications were described to minimize excursions of hemoglobin levels into the Grade 3 or Grade 4 range.

Interventions

DRUGRuxolitinib

Ruxolitinib was provided as 5 mg tablets. Dose increases were only permitted at wks 12 & 18 for lack of efficacy. Increases were restricted to patients who didn't meet criteria for a dose hold over the prior 6 wks, had a platelet count ≥ 100 x 10\^9/L at wk 12 or ≥ 150 x 10\^9/L at wk 18, and had a self-reported PGIC score of 3 (minimally improved) to 7 (very much worse) OR the subject's palpable spleen length below the costal margin was reduced by less than 40% relative to Baseline. Dose increases were elective and not required. Subjects were permitted a dose increase of 5 mg BID to 15 mg BID at wk 12 and to a maximum of 20 mg BID at wk 18. The protocol required dose decreases for thrombocytopenia (platelets \<100 x 10\^9/L) or protocol-defined anemia (decline in hemoglobin of at least 2 g/dL to a level \< 8 g/dL, development of transfusion dependence, or a 50% increase in transfusion requirements for transfusion dependent subjects).

Sponsors

Incyte Corporation
Lead SponsorINDUSTRY

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* Diagnosis of Primary Myelofibrosis (PMF), Post-Polycythemia Vera Myelofibrosis (PPV-MF), or Post-Essential Thrombocythemia Myelofibrosis (PET-MF) as confirmed by bone marrow biopsy. * Must score at least 2 points on the Dynamic International Prognostic Scoring System (DIPSS) scale for prognostic risk factors. * Peripheral blast count \< 5% at both Screening and Baseline hematology assessments. * Must discontinue all drugs used to treat underlying myelofibrosis (MF) disease no later than Day -1 (the day prior to starting ruxolitinib). * Must have hemoglobin value ≥ 6.5 g/dL and be willing to receive blood transfusions. * Platelet count ≥ 100\*10\^9/L. * Must have a palpable spleen.

Exclusion criteria

* Inadequate liver or bone marrow reserves, end stage renal disease on dialysis, clinically significant concurrent infections requiring therapy, or unstable cardiac function. * Invasive malignancies over the previous 5 years (except treated early stage carcinomas of the skin, completely resected intraepithelial carcinoma of the cervix, and completely resected papillary thyroid and follicular thyroid cancers). * Splenic irradiation within 6 months prior to receiving the first dose of study medication. * Life expectancy less than 6 months.

Design outcomes

Primary

MeasureTime frameDescription
Median Percent Change From Baseline in Spleen Volume at Week 24Baseline to Week 24Spleen volume was measured using magnetic resonance imaging (MRI) or computed tomography (CT) scan. The MRIs were read in the central imaging laboratory. Spleen volume was obtained by outlining the circumference of the organ and determining the volume using the technique of least squares. MRI was the preferred method for obtaining spleen volume data. CT scans were performed if the participant was not a candidate for MRI. The CT scans were processed by the same central laboratory used for MRIs. The same method (MRI or CT) was used for all visits for a given participant unless a new contraindication to the use of MRI (eg, pacemaker insertion) occurred.
Mean Percentage Change From Baseline in Spleen Volume at Week 24Baseline to Week 24Spleen volume was measured using magnetic resonance imaging (MRI) or computed tomography (CT) scan. The MRIs were read in the central imaging laboratory. Spleen volume was obtained by outlining the circumference of the organ and determining the volume using the technique of least squares. MRI was the preferred method for obtaining spleen volume data. CT scans were performed if the participant was not a candidate for MRI. The CT scans were processed by the same central laboratory used for MRIs. The same method (MRI or CT) was used for all visits for a given participant unless a new contraindication to the use of MRI (eg, pacemaker insertion) occurred.

Secondary

MeasureTime frameDescription
Median Percent Change From Baseline in the Total Symptom Score at Week 24Baseline to Week 24Symptoms of myelofibrosis were assessed using a symptom diary, the modified MFSAF v2.0. Participants were issued a hand-held device to record answers to queries regarding 7 symptoms of myelofibrosis each night from Baseline through Week 24. Symptoms assessed included night sweats, itching, abdominal discomfort, pain under ribs on left, feeling of fullness (early satiety), muscle/bone pain, and inactivity. The daily TSS was the sum of the first 6 individual symptom scores (each on a scale of 0-10). Inactivity was not included in the total score. The Baseline total symptom score was the mean of daily total symptom scores from the last 7 consecutive days prior to the first study dose and ranged from 0 to 60. The Week 24 total symptom score was the mean of the daily total symptom scores from the last 28 consecutive days prior to the Week 24 visit and ranged from 0 to 60. A higher score indicates worse symptoms. A negative change score indicates improvement.
Percentage of Participants With a ≥ 35% Reduction From Baseline in Spleen Volume at Week 24Baseline to Week 24Spleen volume was measured using magnetic resonance imaging (MRI) or computed tomography (CT) scan. The MRIs were read in the central imaging laboratory. Spleen volume was obtained by outlining the circumference of the organ and determining the volume using the technique of least squares. MRI was the preferred method for obtaining spleen volume data. CT scans were performed if the participant was not a candidate for MRI. The CT scans were processed by the same central laboratory used for MRIs. The same method (MRI or CT) was used for all visits for a given participant unless a new contraindication to the use of MRI (eg, pacemaker insertion) occurred.
Percentage of Participants With a ≥ 10% Reduction From Baseline in Spleen Volume at Week 24Baseline to Week 24Spleen volume was measured using magnetic resonance imaging (MRI) or computed tomography (CT) scan. The MRIs were read in the central imaging laboratory. Spleen volume was obtained by outlining the circumference of the organ and determining the volume using the technique of least squares. MRI was the preferred method for obtaining spleen volume data. CT scans were performed if the participant was not a candidate for MRI. The CT scans were processed by the same central laboratory used for MRIs. The same method (MRI or CT) was used for all visits for a given participant unless a new contraindication to the use of MRI (eg, pacemaker insertion) occurred.
Percentage of Participants With a ≥ 50% Improvement From Baseline in Total Symptom Score at Week 24Baseline to Week 24Symptoms of myelofibrosis were assessed using a symptom diary, the modified MFSAF v2.0. Participants were issued a hand-held device to record answers to queries regarding 7 symptoms of myelofibrosis each night from Baseline through Week 24. Symptoms assessed included night sweats, itching, abdominal discomfort, pain under ribs on left, feeling of fullness (early satiety), muscle/bone pain, and inactivity. The daily total symptom score was the sum of the first 6 individual symptom scores (each on a scale of 0-10). Inactivity was not included in the total score. The Baseline total symptom score was the mean of daily total symptom scores from the last 7 consecutive days prior to the first study dose and ranged from 0 to 60. The Week 24 total symptom score was the mean of the daily total symptom scores from the last 28 consecutive days prior to the Week 24 visit and ranged from 0 to 60. A higher score indicates worse symptoms. A negative change score indicates improvement.
Mean Percentage Change From Baseline in Palpable Spleen Length at Week 24Baseline to Week 24Spleen length was assessed by manual palpation. The edge of the spleen was determined by palpation and measured in centimeters, using a soft ruler, from the costal margin to the point of greatest splenic protrusion.
Percentage of Participants With a ≥ 50% Improvement From Baseline in Their Transfusion Status or With New Transfusion Independence Status for Those Participants Who Were Transfusion Dependent at BaselineBaseline to Week 24Transfusion dependence at Baseline is defined as subjects who received ≥ 2 units of red blood cell product(s) in the 12 consecutive weeks prior to the date of first dose. Transfusion independence On-Study is defined as subjects who received 0 units of red blood cell products over any 12-week period after starting dosing with ruxolitinib. Improvement in transfusion dependence On-Study is defined as a 50% or greater reduction in the frequency of red blood cell transfusions over any 12-week period after starting dosing with ruxolitinib.
Percentage of Participants With Clinically Notable AnemiaBaseline to Weeks 12, 18 and 24Clinically Notable Anemia was a pre-specified safety parameter examined at Weeks 12, 18 and 24 and defined as: 1) New onset Grade 3 or higher anemia in subjects who are transfusion independent at Baseline, 2) New onset transfusion dependence in subjects who are transfusion independent at Baseline, defined as receipt of ≥ 2 units in ≤ a 12-week interval, 3) 50% increase in transfusions compared to Baseline in subjects who are transfusion dependent at Baseline.
Mean Percentage Change in Abdominal Symptom Scores at Week 24.Week 24Symptoms of myelofibrosis were assessed using a symptom diary, the modified MFSAF v2.0. Participants were issued a hand-held device to record answers to queries regarding 7 symptoms of myelofibrosis each night from Baseline through Week 24. The abdominal symptom score was the sum of 3 individual symptom scores (abdominal discomfort, pain under ribs on left side, and feeling of fullness \[early satiety\]), each on a scale of 0 to 10. A higher score indicates worse symptoms. A negative change score indicates improvement. The Baseline abdominal symptom score was the mean of daily abdominal symptom scores from the last 7 consecutive days prior to the first study dose and ranged from 0 to 30. The Week 24 abdominal symptom score was the mean of the daily abdominal symptom scores from the last 28 consecutive days prior to the Week 24 visit and ranged from 0 to 30.
Median Percentage Change in Abdominal Symptom Scores at Week 24.Week 24Symptoms of myelofibrosis were assessed using a symptom diary, the modified MFSAF v2.0. Participants were issued a hand-held device to record answers to queries regarding 7 symptoms of myelofibrosis each night from Baseline through Week 24. The abdominal symptom score was the sum of 3 individual symptom scores (abdominal discomfort, pain under ribs on left side, and feeling of fullness \[early satiety\]).
Number of Participants With Grade 3 or Grade 4 Adverse EventsBaseline to the end of the study
Median Percent Change From Baseline in Palpable Spleen Length at Week 24Baseline to Week 24Spleen length was assessed by manual palpation. The edge of the spleen was determined by palpation and measured in centimeters, using a soft ruler, from the costal margin to the point of greatest splenic protrusion.
Mean Percentage Change From Baseline in the Total Symptom Score at Week 24Baseline to Week 24Symptoms of myelofibrosis were assessed using a symptom diary, the modified Myelofibrosis Symptom Assessment Form (MFSAF v2.0). Participants were issued a hand-held device to record answers to queries regarding 7 symptoms of myelofibrosis each night from Baseline through Week 24. Symptoms assessed included night sweats, itching, abdominal discomfort, pain under ribs on left, feeling of fullness (early satiety), muscle/bone pain, and inactivity. The daily total symptom score (TSS) was the sum of the first 6 individual symptom scores (each on a scale of 0-10). Inactivity was not included in the total score. The Baseline TSS was the mean of daily total symptom scores from the last 7 consecutive days prior to the first study dose and ranged from 0 to 60. The Week 24 TSS was the mean of the daily total symptom scores from the last 28 consecutive days prior to the Week 24 visit and ranged from 0 to 60. A higher score indicates worse symptoms. A negative change score indicates improvement.

Other

MeasureTime frameDescription
Dose Distribution at Week 24Week 24Average Daily Dose for the last 28 days on study.

Countries

United States

Participant flow

Participants by arm

ArmCount
Ruxolitinib
Participants initially received ruxolitinib 10 mg twice a day (bid). Dose increases of 5 mg bid were permitted at Weeks 12 and 18 for subjects who did not meet criteria for or have a dose hold over the prior 6 weeks, had a platelet count ≥ 100 x 10\^9/L at week 12 or ≥ 150 x 10\^9/L at week 18, and had a self-reported PGIC score of 3 (minimally improved) to 7 (very much worse) OR the subject's palpable spleen length had been reduced by less than 40% at that visit relative to Baseline. The maximum dose was 15 mg BID at Week 12 and 20 mg bid at Week 18. There were also protocol-required dose decreases for protocol-defined anemia and thrombocytopenia.
45
Total45

Withdrawals & dropouts

PeriodReasonFG000
Overall StudyConsent Withdrawn2
Overall StudyDisease Progression1
Overall StudyLost to Follow-up5

Baseline characteristics

CharacteristicRuxolitinib
Age, Continuous70.2 years
STANDARD_DEVIATION 9.1
Sex: Female, Male
Female
21 Participants
Sex: Female, Male
Male
24 Participants

Adverse events

Event typeEG000
affected / at risk
deaths
Total, all-cause mortality
— / —
other
Total, other adverse events
42 / 45
serious
Total, serious adverse events
2 / 45

Outcome results

Primary

Mean Percentage Change From Baseline in Spleen Volume at Week 24

Spleen volume was measured using magnetic resonance imaging (MRI) or computed tomography (CT) scan. The MRIs were read in the central imaging laboratory. Spleen volume was obtained by outlining the circumference of the organ and determining the volume using the technique of least squares. MRI was the preferred method for obtaining spleen volume data. CT scans were performed if the participant was not a candidate for MRI. The CT scans were processed by the same central laboratory used for MRIs. The same method (MRI or CT) was used for all visits for a given participant unless a new contraindication to the use of MRI (eg, pacemaker insertion) occurred.

Time frame: Baseline to Week 24

Population: Intent-to-treat population: All enrolled participants. Note that 2 subjects did not have the Week 24 MRI; one subject dropped out for disease progression and two withdrew consent prior to the Week 24 MRI. Thus 40 subjects were analyzed.

ArmMeasureValue (MEAN)Dispersion
RuxolitinibMean Percentage Change From Baseline in Spleen Volume at Week 24-14.9 Percentage changeStandard Deviation 21.06
Primary

Median Percent Change From Baseline in Spleen Volume at Week 24

Spleen volume was measured using magnetic resonance imaging (MRI) or computed tomography (CT) scan. The MRIs were read in the central imaging laboratory. Spleen volume was obtained by outlining the circumference of the organ and determining the volume using the technique of least squares. MRI was the preferred method for obtaining spleen volume data. CT scans were performed if the participant was not a candidate for MRI. The CT scans were processed by the same central laboratory used for MRIs. The same method (MRI or CT) was used for all visits for a given participant unless a new contraindication to the use of MRI (eg, pacemaker insertion) occurred.

Time frame: Baseline to Week 24

Population: Intent-to-treat population: All enrolled participants. Note that 2 subjects did not have the Week 24 MRI; one subject dropped out for disease progression and two withdrew consent prior to the Week 24 MRI. Thus 40 subjects were analyzed.

ArmMeasureValue (MEDIAN)
RuxolitinibMedian Percent Change From Baseline in Spleen Volume at Week 24-17.3 : Percentage change
Secondary

Mean Percentage Change From Baseline in Palpable Spleen Length at Week 24

Spleen length was assessed by manual palpation. The edge of the spleen was determined by palpation and measured in centimeters, using a soft ruler, from the costal margin to the point of greatest splenic protrusion.

Time frame: Baseline to Week 24

Population: Intent-to-treat population: All enrolled participants. Note that one subject had a non-palpable spleen at baseline, one subject did not have the Week 24 spleen palpation performed; one subject dropped out for disease progression and two withdrew consent prior to the Week 24 spleen palpation. Thus 40 subjects were analyzed.

ArmMeasureValue (MEAN)Dispersion
RuxolitinibMean Percentage Change From Baseline in Palpable Spleen Length at Week 24-47.6 Percentage changeStandard Deviation 42.05
Secondary

Mean Percentage Change From Baseline in the Total Symptom Score at Week 24

Symptoms of myelofibrosis were assessed using a symptom diary, the modified Myelofibrosis Symptom Assessment Form (MFSAF v2.0). Participants were issued a hand-held device to record answers to queries regarding 7 symptoms of myelofibrosis each night from Baseline through Week 24. Symptoms assessed included night sweats, itching, abdominal discomfort, pain under ribs on left, feeling of fullness (early satiety), muscle/bone pain, and inactivity. The daily total symptom score (TSS) was the sum of the first 6 individual symptom scores (each on a scale of 0-10). Inactivity was not included in the total score. The Baseline TSS was the mean of daily total symptom scores from the last 7 consecutive days prior to the first study dose and ranged from 0 to 60. The Week 24 TSS was the mean of the daily total symptom scores from the last 28 consecutive days prior to the Week 24 visit and ranged from 0 to 60. A higher score indicates worse symptoms. A negative change score indicates improvement.

Time frame: Baseline to Week 24

Population: Intent-to-treat population: All enrolled participants. Note that 3 subjects did not have the Week 24 TSS; one subject dropped out for disease progression and two withdrew consent prior to the Week 24 TSS assessment. Thus 39 subjects were analyzed.

ArmMeasureValue (MEAN)Dispersion
RuxolitinibMean Percentage Change From Baseline in the Total Symptom Score at Week 24-34.3 Percentage changeStandard Deviation 69.05
Secondary

Mean Percentage Change in Abdominal Symptom Scores at Week 24.

Symptoms of myelofibrosis were assessed using a symptom diary, the modified MFSAF v2.0. Participants were issued a hand-held device to record answers to queries regarding 7 symptoms of myelofibrosis each night from Baseline through Week 24. The abdominal symptom score was the sum of 3 individual symptom scores (abdominal discomfort, pain under ribs on left side, and feeling of fullness \[early satiety\]), each on a scale of 0 to 10. A higher score indicates worse symptoms. A negative change score indicates improvement. The Baseline abdominal symptom score was the mean of daily abdominal symptom scores from the last 7 consecutive days prior to the first study dose and ranged from 0 to 30. The Week 24 abdominal symptom score was the mean of the daily abdominal symptom scores from the last 28 consecutive days prior to the Week 24 visit and ranged from 0 to 30.

Time frame: Week 24

Population: Intent-to-treat population: All enrolled participants. Note that three subjects did not have the Week 24 TSS; one subject dropped out for disease progression and two withdrew consent prior to the Week 24 TSS assessment. Thus 39 subjects were analyzed.

ArmMeasureValue (MEAN)Dispersion
RuxolitinibMean Percentage Change in Abdominal Symptom Scores at Week 24.-33.2 Percentage changeStandard Deviation 69.83
Secondary

Median Percentage Change in Abdominal Symptom Scores at Week 24.

Symptoms of myelofibrosis were assessed using a symptom diary, the modified MFSAF v2.0. Participants were issued a hand-held device to record answers to queries regarding 7 symptoms of myelofibrosis each night from Baseline through Week 24. The abdominal symptom score was the sum of 3 individual symptom scores (abdominal discomfort, pain under ribs on left side, and feeling of fullness \[early satiety\]).

Time frame: Week 24

Population: Intent-to-treat population: All enrolled participants. Note that three subjects did not have the Week 24 TSS; one subject dropped out for disease progression and two withdrew consent prior to the Week 24 TSS assessment. Thus 39 subjects were analyzed.

ArmMeasureValue (MEDIAN)
RuxolitinibMedian Percentage Change in Abdominal Symptom Scores at Week 24.-50.5 Percentage change
Secondary

Median Percent Change From Baseline in Palpable Spleen Length at Week 24

Spleen length was assessed by manual palpation. The edge of the spleen was determined by palpation and measured in centimeters, using a soft ruler, from the costal margin to the point of greatest splenic protrusion.

Time frame: Baseline to Week 24

Population: Intent-to-treat population: All enrolled participants. Note that one subject had a non-palpable spleen at baseline, one subject did not have the Week 24 spleen palpation performed; one subject dropped out for disease progression and two withdrew consent prior to the Week 24 spleen palpation. Thus 40 subjects were analyzed.

ArmMeasureValue (MEDIAN)
RuxolitinibMedian Percent Change From Baseline in Palpable Spleen Length at Week 24-39.8 Percentage change
Secondary

Median Percent Change From Baseline in the Total Symptom Score at Week 24

Symptoms of myelofibrosis were assessed using a symptom diary, the modified MFSAF v2.0. Participants were issued a hand-held device to record answers to queries regarding 7 symptoms of myelofibrosis each night from Baseline through Week 24. Symptoms assessed included night sweats, itching, abdominal discomfort, pain under ribs on left, feeling of fullness (early satiety), muscle/bone pain, and inactivity. The daily TSS was the sum of the first 6 individual symptom scores (each on a scale of 0-10). Inactivity was not included in the total score. The Baseline total symptom score was the mean of daily total symptom scores from the last 7 consecutive days prior to the first study dose and ranged from 0 to 60. The Week 24 total symptom score was the mean of the daily total symptom scores from the last 28 consecutive days prior to the Week 24 visit and ranged from 0 to 60. A higher score indicates worse symptoms. A negative change score indicates improvement.

Time frame: Baseline to Week 24

Population: Intent-to-treat population: All enrolled participants. Note that 3 subjects did not have the Week 24 TSS; one subject dropped out for disease progression and two withdrew consent prior to the Week 24 TSS assessment. Thus 39 subjects were analyzed.

ArmMeasureValue (MEDIAN)
RuxolitinibMedian Percent Change From Baseline in the Total Symptom Score at Week 24-45.6 Percentage change
Secondary

Number of Participants With Grade 3 or Grade 4 Adverse Events

Time frame: Baseline to the end of the study

Population: Safety population: All participants who took at least 1 dose of study drug.

ArmMeasureGroupValue (NUMBER)
RuxolitinibNumber of Participants With Grade 3 or Grade 4 Adverse EventsUmbilical hernia (Grade 3)1 participants
RuxolitinibNumber of Participants With Grade 3 or Grade 4 Adverse EventsAnemia (Grade 3)9 participants
RuxolitinibNumber of Participants With Grade 3 or Grade 4 Adverse EventsThrombocytopenia (Grade 3)1 participants
RuxolitinibNumber of Participants With Grade 3 or Grade 4 Adverse EventsCholelithiasis (Grade 3)1 participants
RuxolitinibNumber of Participants With Grade 3 or Grade 4 Adverse EventsBlood creatine phosphokinase increased (Grade 3)1 participants
RuxolitinibNumber of Participants With Grade 3 or Grade 4 Adverse EventsBlood triglycerides increased (Grade 3)1 participants
RuxolitinibNumber of Participants With Grade 3 or Grade 4 Adverse EventsLipase increased (Grade 3)1 participants
RuxolitinibNumber of Participants With Grade 3 or Grade 4 Adverse EventsDehydration (Grade 3)1 participants
RuxolitinibNumber of Participants With Grade 3 or Grade 4 Adverse EventsHyperkalaemia (Grade 3)1 participants
RuxolitinibNumber of Participants With Grade 3 or Grade 4 Adverse EventsHypermagnesaemia (Grade 3)1 participants
RuxolitinibNumber of Participants With Grade 3 or Grade 4 Adverse EventsDizziness (Grade 3)1 participants
RuxolitinibNumber of Participants With Grade 3 or Grade 4 Adverse EventsMyelodysplastic syndrome (Grade 4)1 participants
Secondary

Percentage of Participants With a ≥ 10% Reduction From Baseline in Spleen Volume at Week 24

Spleen volume was measured using magnetic resonance imaging (MRI) or computed tomography (CT) scan. The MRIs were read in the central imaging laboratory. Spleen volume was obtained by outlining the circumference of the organ and determining the volume using the technique of least squares. MRI was the preferred method for obtaining spleen volume data. CT scans were performed if the participant was not a candidate for MRI. The CT scans were processed by the same central laboratory used for MRIs. The same method (MRI or CT) was used for all visits for a given participant unless a new contraindication to the use of MRI (eg, pacemaker insertion) occurred.

Time frame: Baseline to Week 24

Population: Intent-to-treat population: All enrolled participants.

ArmMeasureValue (NUMBER)
RuxolitinibPercentage of Participants With a ≥ 10% Reduction From Baseline in Spleen Volume at Week 2457.8 Percentage of participants
Secondary

Percentage of Participants With a ≥ 35% Reduction From Baseline in Spleen Volume at Week 24

Spleen volume was measured using magnetic resonance imaging (MRI) or computed tomography (CT) scan. The MRIs were read in the central imaging laboratory. Spleen volume was obtained by outlining the circumference of the organ and determining the volume using the technique of least squares. MRI was the preferred method for obtaining spleen volume data. CT scans were performed if the participant was not a candidate for MRI. The CT scans were processed by the same central laboratory used for MRIs. The same method (MRI or CT) was used for all visits for a given participant unless a new contraindication to the use of MRI (eg, pacemaker insertion) occurred.

Time frame: Baseline to Week 24

Population: Intent-to-treat population: All enrolled participants.

ArmMeasureValue (NUMBER)
RuxolitinibPercentage of Participants With a ≥ 35% Reduction From Baseline in Spleen Volume at Week 2415.6 Percentage of participants
Secondary

Percentage of Participants With a ≥ 50% Improvement From Baseline in Their Transfusion Status or With New Transfusion Independence Status for Those Participants Who Were Transfusion Dependent at Baseline

Transfusion dependence at Baseline is defined as subjects who received ≥ 2 units of red blood cell product(s) in the 12 consecutive weeks prior to the date of first dose. Transfusion independence On-Study is defined as subjects who received 0 units of red blood cell products over any 12-week period after starting dosing with ruxolitinib. Improvement in transfusion dependence On-Study is defined as a 50% or greater reduction in the frequency of red blood cell transfusions over any 12-week period after starting dosing with ruxolitinib.

Time frame: Baseline to Week 24

Population: Intent-to-treat population: All enrolled participants who were transfusion dependent at baseline (n=15).

ArmMeasureValue (NUMBER)
RuxolitinibPercentage of Participants With a ≥ 50% Improvement From Baseline in Their Transfusion Status or With New Transfusion Independence Status for Those Participants Who Were Transfusion Dependent at Baseline20.0 Percentage of participants
Secondary

Percentage of Participants With a ≥ 50% Improvement From Baseline in Total Symptom Score at Week 24

Symptoms of myelofibrosis were assessed using a symptom diary, the modified MFSAF v2.0. Participants were issued a hand-held device to record answers to queries regarding 7 symptoms of myelofibrosis each night from Baseline through Week 24. Symptoms assessed included night sweats, itching, abdominal discomfort, pain under ribs on left, feeling of fullness (early satiety), muscle/bone pain, and inactivity. The daily total symptom score was the sum of the first 6 individual symptom scores (each on a scale of 0-10). Inactivity was not included in the total score. The Baseline total symptom score was the mean of daily total symptom scores from the last 7 consecutive days prior to the first study dose and ranged from 0 to 60. The Week 24 total symptom score was the mean of the daily total symptom scores from the last 28 consecutive days prior to the Week 24 visit and ranged from 0 to 60. A higher score indicates worse symptoms. A negative change score indicates improvement.

Time frame: Baseline to Week 24

Population: Intent-to-treat population: All enrolled participants.

ArmMeasureValue (NUMBER)
RuxolitinibPercentage of Participants With a ≥ 50% Improvement From Baseline in Total Symptom Score at Week 2440.0 Percentage of participants
Secondary

Percentage of Participants With Clinically Notable Anemia

Clinically Notable Anemia was a pre-specified safety parameter examined at Weeks 12, 18 and 24 and defined as: 1) New onset Grade 3 or higher anemia in subjects who are transfusion independent at Baseline, 2) New onset transfusion dependence in subjects who are transfusion independent at Baseline, defined as receipt of ≥ 2 units in ≤ a 12-week interval, 3) 50% increase in transfusions compared to Baseline in subjects who are transfusion dependent at Baseline.

Time frame: Baseline to Weeks 12, 18 and 24

Population: Safety population: All participants who took at least 1 dose of study drug.

ArmMeasureGroupValue (NUMBER)
RuxolitinibPercentage of Participants With Clinically Notable AnemiaWeek 1233.3 Percentage of participants
RuxolitinibPercentage of Participants With Clinically Notable AnemiaWeek 1827.3 Percentage of participants
RuxolitinibPercentage of Participants With Clinically Notable AnemiaWeek 2427.9 Percentage of participants
Other Pre-specified

Dose Distribution at Week 24

Average Daily Dose for the last 28 days on study.

Time frame: Week 24

Population: Intent-to-treat population: All enrolled participants.

ArmMeasureGroupValue (NUMBER)
RuxolitinibDose Distribution at Week 240-5 mg2 participants
RuxolitinibDose Distribution at Week 24> 5-10 mg14 participants
RuxolitinibDose Distribution at Week 24> 10-20 mg12 participants
RuxolitinibDose Distribution at Week 24> 20-30 mg12 participants
RuxolitinibDose Distribution at Week 24> 30-40 mg5 participants

Source: ClinicalTrials.gov · Data processed: Mar 5, 2026