A Phase 3 interventional study of Placebo for Navitoclax and Ruxolitinib in Myelofibrosis (MF), sponsored by AbbVie. Completed at 194 sites in 25 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-03-23.
Sponsored by AbbVie · Phase 3, Interventional, and Treatment
Myelofibrosis is a type of bone marrow cancer that usually develops slowly and disrupts body's normal production of blood cells. It causes bone marrow scarring, leading to severe anemia that can cause weakness and fatigue. It can also cause a low number of blood-clotting cells called platelets, which increases risk of bleeding. Myelofibrosis often causes an enlarged spleen. The purpose of this study is to see if a combination of navitoclax and ruxolitinib is more effective and safe in assessment of change in spleen volume when compared to ruxolitinib in participants with myelofibrosis.
Navitoclax is an investigational drug for the treatment of myelofibrosis. Participants in this study are divided into two groups, called treatment arms. Each group receives a different treatment. Adult participants with a diagnosis of myelofibrosis will be enrolled. Around 230 participants will be enrolled in approximately 190 sites worldwide.
Participants will receive oral navitoclax tablet with oral ruxolitinib tablet or oral ruxolitinib tablet with oral placebo (no active drug) tablet and treatment may continue untill the participant cannot tolerate the study drug, or benefit is not achieved, or other reasons which qualify for discontinuation of the study drug.
There may be a higher treatment burden for participants in this trial compared to their standard of care. Participants will attend regular visits during the course of the study at a hospital or clinic. The effect of the treatment will be checked by medical assessments, blood tests, magnetic resonance imaging (MRI) or computed tomography (CT) scan, bone marrow tests, checking for side effects, and completing questionnaires.
419 studies on the registry are indexed under Primary Myelofibrosis; 117 are open to participants now.
This study's enrollment of 252 is above the median of 44 across 347 interventional studies indexed under Primary Myelofibrosis.
Browse Primary Myelofibrosis studies →AbbVie is the lead sponsor of 953 studies on the registry; 136 are open to participants now.
Of its 350 completed or terminated interventional studies of FDA-regulated products, 210 (60%) have results posted.
Counted across the registry records on this site, refreshed daily.
Must be able to complete the MF Symptom Assessment Form (MFSAF) v4.0 on at least 4 out of 7 days immediately preceding the date of randomization.
-- Must have at least 2 symptoms with a score >=3 or a total score of >=12, as measured by the MFSAF v4.0.
Exclusion Criteria:
Placebo for navitoclax tablets were administered orally once daily (QD) per Baseline platelet count (\>150 × 10\^9/L starting dose of 200 mg; ≤150 × 10\^9/L starting dose of 100 mg, which could be increased to 200 mg QD after 7 days provided platelet count is ≥75 × 10\^9/L). Placebo for navitoclax didn't exceed 200 mg QD for first 24 weeks of treatment. After Week 25, Day 1 visit, placebo for navitoclax dose may be increased to 300 mg QD at Investigator's discretion for those with suboptimal spleen response defined as failure to achieve spleen volume reduction of at least 10% per imaging. Ruxolitinib tablets were administered orally twice daily (BID) per Baseline platelet count (\>200 × 10\^9/L starting dose of 20 mg; 100-200 × 10\^9/L starting dose of 15 mg). Participants will continue their treatment until end of clinical benefit, unacceptable toxicity, or they meet other protocol criteria for discontinuation (whichever occurs first).
Drug: Placebo for Navitoclax · Drug: Ruxolitinib
Navitoclax tablets were administered orally once daily (QD) per Baseline platelet count (\>150 × 10\^9/L starting dose of 200 mg; ≤150 × 10\^9/L starting dose of 100 mg, which could be increased to 200 mg QD after 7 days provided platelet count is ≥75 × 10\^9/L). Navitoclax didn't exceed 200 mg QD for first 24 weeks of treatment. After Week 25, Day 1 visit, navitoclax dose may be increased to 300 mg QD at Investigator's discretion for those with suboptimal spleen response defined as failure to achieve spleen volume reduction of at least 10% per imaging. Ruxolitinib tablets were administered orally twice daily (BID) per Baseline platelet count (\>200 × 10\^9/L starting dose of 20 mg; 100-200 × 10\^9/L starting dose of 15 mg). Participants will continue their treatment until end of clinical benefit, unacceptable toxicity, or they meet other protocol criteria for discontinuation (whichever occurs first).
Drug: Ruxolitinib · Drug: Navitoclax
Film-coated tablet; Oral
Tablet; Oral
Also known as: Jakafi
Film-coated tablet; Oral
Also known as: ABT-263
Percentage of Participants With ≥ 35% Reduction From Baseline in Spleen Volume at Week 24 (SVR35W24)
Reduction in spleen volume is measured by magnetic resonance imaging (MRI) or computed tomography (CT), per International Working Group (IWG) criteria.
Time frame: Baseline, Week 24
Change From Baseline in Total Symptom Score (TSS) at Week 24 as Measured by Myelofibrosis Symptom Assessment Form (MFSAF) v4.0
TSS is assessed by the Myelofibrosis Symptom Assessment Form (MFSAF) version 4.0. Participants complete a symptom diary and rate the following seven MF symptoms: fatigue, night sweats, abdominal discomfort, pruritus, pain under the ribs on the left side, early satiety, and bone pain daily using a scale from 0 (absent) to 10 (worst imaginable), and the scores are averaged over 7 days, with a minimum of 4 days required to calculate the average score. Participants for whom a valid average score cannot be calculated either at baseline or post-baseline are considered non-responders. The TSS reflects the sum of the scores of these symptoms, for a maximum possible score of 70 (i.e., most severe symptom experience). Negative changes from Baseline indicate improvement.
Time frame: Baseline, Week 24
Percentage of Participants With ≥ 35% Reduction From Baseline in Spleen Volume (SVR35) at Any Time
Reduction in spleen volume is measured by magnetic resonance imaging (MRI) or computed tomography (CT), per International Working Group (IWG) criteria.
Time frame: Up to Week 97
Duration of 35% Spleen Volume Reduction (SVR35)
Duration of SVR35 is defined as the time between the date of first response of spleen volume reduction of 35% achievement to the date of the first assessment where the spleen volume is less than 35% reduction from Baseline and is at least 25% increase from the nadir (the lowest spleen volume), confirmed relapse, or leukemic transformation per International Working Group (IWG) criteria, whichever is earlier.
Time frame: Baseline (Week 0) Up to Month 48
Change From Baseline In Fatigue at Week 24 as Measured by the PROMIS Fatigue Short Form (SF) 7a
The PROMIS Fatigue SF 7a is a 7-item patient-reported outcome measure that assesses the impact and experience of participants with fatigue over the past 7 days. Each item is scored on a 5-point Likert scale (1 = Never, 2 = Rarely, 3 = Sometimes, 4 = Often, and 5 = Always). Raw scores range from 7 to 35 and are subsequently transformed into a standardized T-score using the PROMIS wave 1 calibration (where a score of 50 represents the U.S. general population mean with a standard deviation of 10). Higher T-scores indicate greater fatigue severity. A decrease in T-score from Baseline represents a clinical improvement in fatigue symptoms.
Time frame: Baseline, Week 24
Change From Baseline at Week 24 in Physical Functioning as Measured by the Physical Functioning Domain of the European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLQ)-C30
EORTC QLQ-C30 is a 30-item participant self-report questionnaire composed of both multi-item and single scales, including a physical functioning scale. Participants rate items and a score ranging from 0 to 100 is calculated. A higher score on the physical functioning scale indicates a better level of functioning, and positive changes from Baseline indicate improvement.
Time frame: Baseline, Week 24
Percentage of Participants Achieving Anemia Response
For a participant who is transfusion independent (TI) at Baseline with hemoglobin value \< 10 g/dL, anemia response is achieved if the post-Baseline hemoglobin level increases by ≥2 g/dL without receiving packed red blood cells (PRBC) transfusion (for any reason) within 2 weeks and without any erythropoietin or mimetics within the last 4 weeks prior to the increase in hemoglobin level by ≥2g/dL was observed. Hemoglobin values more than 30 days after the last dose of study treatment or after the start of post-study treatment or disease progression, whichever is earlier, will not be considered in the analysis of anemia response. For a participant who is transfusion dependent (TD) at Baseline, anemia response is defined as a period of at least 12 consecutive weeks without PRBC transfusion at any time after the first dose of study drug and on or prior to 30 days post last dose of study drug, the start of post-study treatment, disease progression or death, whichever occurs earlier.
Time frame: Up to Week 97
Overall Survival (OS)
OS is defined as the time from the date of randomization to the date of death from any cause.
Time frame: Up to 50 months
Leukemia-Free Survival
Leukemia-free survival is defined as the number of days from the date of randomization to the onset date of documented leukemia, disease progression due to leukemia, or death due to leukemia, whichever occurs first.
Time frame: Up to 50 months
Percentage of Participants Who Achieved Reduction in Grade of Bone Marrow Fibrosis From Baseline at Any Time
Change in grade of bone marrow fibrosis was measured per the European consensus grading system through bone marrow biopsy. The percentage of participants who achieved reduction of at least 1 grade in bone marrow fibrosis compared to Baseline is reported.
Time frame: Up to Week 97
This trial was conducted in 24 countries.
| Milestone | Placebo for Navitoclax + Ruxolitinib | Navitoclax + Ruxolitinib |
|---|---|---|
| Started | 127 | 125 |
| Completed | 0 | 0 |
| Not completed | 127 | 125 |
| Withdrew: Lost to follow-up | 1 | 2 |
| Withdrew: Death | 28 | 35 |
| Withdrew: Withdrew consent | 15 | 7 |
| Withdrew: Other, not specified | 83 | 81 |
Reduction in spleen volume is measured by magnetic resonance imaging (MRI) or computed tomography (CT), per International Working Group (IWG) criteria.
| percentage of participants | Placebo for Navitoclax + Ruxolitinib | Navitoclax + Ruxolitinib |
|---|---|---|
| Percentage of Participants With ≥ 35% Reduction From Baseline in Spleen Volume at Week 24 (SVR35W24) | 31.50 (23.55 to 40.33) | 63.20 (54.11 to 71.65) |
TSS is assessed by the Myelofibrosis Symptom Assessment Form (MFSAF) version 4.0. Participants complete a symptom diary and rate the following seven MF symptoms: fatigue, night sweats, abdominal discomfort, pruritus, pain under the ribs on the left side, early satiety, and bone pain daily using a scale from 0 (absent) to 10 (worst imaginable), and the scores are averaged over 7 days, with a minimum of 4 days required to calculate the average score. Participants for whom a valid average score cannot be calculated either at baseline or post-baseline are considered non-responders. The TSS reflects the sum of the scores of these symptoms, for a maximum possible score of 70 (i.e., most severe symptom experience). Negative changes from Baseline indicate improvement.
| units on a scale | Placebo for Navitoclax + Ruxolitinib | Navitoclax + Ruxolitinib |
|---|---|---|
| Change From Baseline in Total Symptom Score (TSS) at Week 24 as Measured by Myelofibrosis Symptom Assessment Form (MFSAF) v4.0 | -11.14 (-13.23 to -9.05) | -9.71 (-11.80 to -7.62) |
Reduction in spleen volume is measured by magnetic resonance imaging (MRI) or computed tomography (CT), per International Working Group (IWG) criteria.
| percentage of participants | Placebo for Navitoclax + Ruxolitinib | Navitoclax + Ruxolitinib |
|---|---|---|
| Percentage of Participants With ≥ 35% Reduction From Baseline in Spleen Volume (SVR35) at Any Time | 44.09 (35.30 to 53.17) | 76.80 (68.41 to 83.88) |
Duration of SVR35 is defined as the time between the date of first response of spleen volume reduction of 35% achievement to the date of the first assessment where the spleen volume is less than 35% reduction from Baseline and is at least 25% increase from the nadir (the lowest spleen volume), confirmed relapse, or leukemic transformation per International Working Group (IWG) criteria, whichever is earlier.
| months | Placebo for Navitoclax + Ruxolitinib | Navitoclax + Ruxolitinib |
|---|---|---|
| Duration of 35% Spleen Volume Reduction (SVR35) | NA (19.38 to NA) | NA (27.60 to NA) |
The PROMIS Fatigue SF 7a is a 7-item patient-reported outcome measure that assesses the impact and experience of participants with fatigue over the past 7 days. Each item is scored on a 5-point Likert scale (1 = Never, 2 = Rarely, 3 = Sometimes, 4 = Often, and 5 = Always). Raw scores range from 7 to 35 and are subsequently transformed into a standardized T-score using the PROMIS wave 1 calibration (where a score of 50 represents the U.S. general population mean with a standard deviation of 10). Higher T-scores indicate greater fatigue severity. A decrease in T-score from Baseline represents a clinical improvement in fatigue symptoms.
| T-Score | Placebo for Navitoclax + Ruxolitinib | Navitoclax + Ruxolitinib |
|---|---|---|
| Change From Baseline In Fatigue at Week 24 as Measured by the PROMIS Fatigue Short Form (SF) 7a | -3.63 (-5.38 to -1.88) | -3.75 (-5.46 to -2.04) |
EORTC QLQ-C30 is a 30-item participant self-report questionnaire composed of both multi-item and single scales, including a physical functioning scale. Participants rate items and a score ranging from 0 to 100 is calculated. A higher score on the physical functioning scale indicates a better level of functioning, and positive changes from Baseline indicate improvement.
| units on a scale | Placebo for Navitoclax + Ruxolitinib | Navitoclax + Ruxolitinib |
|---|---|---|
| Change From Baseline at Week 24 in Physical Functioning as Measured by the Physical Functioning Domain of the European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLQ)-C30 | 6.198 (2.238 to 10.158) | 7.326 (3.458 to 11.195) |
For a participant who is transfusion independent (TI) at Baseline with hemoglobin value \< 10 g/dL, anemia response is achieved if the post-Baseline hemoglobin level increases by ≥2 g/dL without receiving packed red blood cells (PRBC) transfusion (for any reason) within 2 weeks and without any erythropoietin or mimetics within the last 4 weeks prior to the increase in hemoglobin level by ≥2g/dL was observed. Hemoglobin values more than 30 days after the last dose of study treatment or after the start of post-study treatment or disease progression, whichever is earlier, will not be considered in the analysis of anemia response. For a participant who is transfusion dependent (TD) at Baseline, anemia response is defined as a period of at least 12 consecutive weeks without PRBC transfusion at any time after the first dose of study drug and on or prior to 30 days post last dose of study drug, the start of post-study treatment, disease progression or death, whichever occurs earlier.
| percentage of participants | Placebo for Navitoclax + Ruxolitinib | Navitoclax + Ruxolitinib |
|---|---|---|
| Overall | 30.56 (20.24 to 42.53) | 28.79 (18.30 to 41.25) |
| Baseline transfusion independent with Baseline Hb <10 g/dL | 29.41 (18.98 to 41.71) | 29.51 (18.52 to 42.57) |
| Baseline transfusion dependent | 50.00 (6.76 to 93.24) | 20.00 (0.51 to 71.64) |
OS is defined as the time from the date of randomization to the date of death from any cause.
| months | Placebo for Navitoclax + Ruxolitinib | Navitoclax + Ruxolitinib |
|---|---|---|
| Overall Survival (OS) | 48.49 (48.49 to NA) | NA (41.36 to NA) |
Leukemia-free survival is defined as the number of days from the date of randomization to the onset date of documented leukemia, disease progression due to leukemia, or death due to leukemia, whichever occurs first.
| months | Placebo for Navitoclax + Ruxolitinib | Navitoclax + Ruxolitinib |
|---|---|---|
| Leukemia-Free Survival | NA (40.05 to NA) | NA (37.62 to NA) |
Change in grade of bone marrow fibrosis was measured per the European consensus grading system through bone marrow biopsy. The percentage of participants who achieved reduction of at least 1 grade in bone marrow fibrosis compared to Baseline is reported.
| percentage of participants | Placebo for Navitoclax + Ruxolitinib | Navitoclax + Ruxolitinib |
|---|---|---|
| Percentage of Participants Who Achieved Reduction in Grade of Bone Marrow Fibrosis From Baseline at Any Time | 48.89 (38.20 to 59.65) | 56.52 (45.78 to 66.83) |
Collected over All-cause mortality and adverse events tables include events reported from the time of informed consent to the end of the study. Median time on follow-up was 35.5 months for the Placebo for Navitoclax + Ruxolitinib group and 35.8 months for the Navitoclax + Ruxolitinib group.. Non-serious events are listed at a 5% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Placebo for Navitoclax + Ruxolitinib | 28/127 (22%) | 56/127 (44.1%) | 115/127 (90.6%) |
| Navitoclax + Ruxolitinib | 35/125 (28%) | 42/125 (33.6%) | 121/125 (96.8%) |
| Event | Placebo for Navitoclax + Ruxolitinib | Navitoclax + Ruxolitinib |
|---|---|---|
| PNEUMONIAInfections and infestations | 5/127 | 6/125 |
| COVID-19Infections and infestations | 6/127 | 1/125 |
| ANAEMIABlood and lymphatic system disorders | 3/127 | 3/125 |
| MULTIPLE ORGAN DYSFUNCTION SYNDROMEGeneral disorders | 0/127 | 3/125 |
| COVID-19 PNEUMONIAInfections and infestations | 3/127 | 3/125 |
| ACUTE KIDNEY INJURYRenal and urinary disorders | 3/127 | 1/125 |
| ATRIAL FIBRILLATIONCardiac disorders | 0/127 | 2/125 |
| DIARRHOEAGastrointestinal disorders | 0/127 | 2/125 |
| URINARY TRACT INFECTIONInfections and infestations | 1/127 | 2/125 |
| SQUAMOUS CELL CARCINOMA OF SKINNeoplasms benign, malignant and unspecified (incl cysts and polyps) | 0/127 | 2/125 |
| Event | Placebo for Navitoclax + Ruxolitinib | Navitoclax + Ruxolitinib |
|---|---|---|
| THROMBOCYTOPENIABlood and lymphatic system disorders | 47/127 | 83/125 |
| ANAEMIABlood and lymphatic system disorders | 64/127 | 81/125 |
| DIARRHOEAGastrointestinal disorders | 21/127 | 50/125 |
| NEUTROPENIABlood and lymphatic system disorders | 10/127 | 38/125 |
| PLATELET COUNT DECREASEDInvestigations | 22/127 | 33/125 |
| COVID-19Infections and infestations | 23/127 | 31/125 |
| ALANINE AMINOTRANSFERASE INCREASEDInvestigations | 12/127 | 26/125 |
| ASPARTATE AMINOTRANSFERASE INCREASEDInvestigations | 16/127 | 24/125 |
| NAUSEAGastrointestinal disorders | 9/127 | 22/125 |
| FATIGUEGeneral disorders | 18/127 | 21/125 |
Intent-to-Treat population: all randomized participants analyzed by the treatment arm assigned at the time of randomization
| Age, Continuous(years) | Placebo for Navitoclax + Ruxolitinib | Navitoclax + Ruxolitinib | Total |
|---|---|---|---|
| Mean | 68.5 ± 8.49 | 68.7 ± 9.17 | 68.6 ± 8.81 |
| Sex: Female, Male(Participants) | Placebo for Navitoclax + Ruxolitinib | Navitoclax + Ruxolitinib | Total |
|---|---|---|---|
| Female | 46 | 62 | 108 |
| Male | 81 | 63 | 144 |
| Ethnicity (NIH/OMB)(Participants) | Placebo for Navitoclax + Ruxolitinib | Navitoclax + Ruxolitinib | Total |
|---|---|---|---|
| Hispanic or Latino | 8 | 7 | 15 |
| Not Hispanic or Latino | 119 | 118 | 237 |
| Unknown or Not Reported | 0 | 0 | 0 |
| Race (NIH/OMB)(Participants) | Placebo for Navitoclax + Ruxolitinib | Navitoclax + Ruxolitinib | Total |
|---|---|---|---|
| American Indian or Alaska Native | 0 | 0 | 0 |
| Asian | 26 | 24 | 50 |
| Native Hawaiian or Other Pacific Islander | 1 | 0 | 1 |
| Black or African American | 1 | 1 | 2 |
| White | 99 | 100 | 199 |
| More than one race | 0 | 0 | 0 |
| Unknown or Not Reported | 0 | 0 | 0 |
Showing the first 100 of 194 sites across 25 countries.
Documents are hosted by the registry — open the source record to download them.
Plan to share: Yes — AbbVie is committed to responsible clinical trial data sharing. This includes access to anonymized, individual and trial-level data (analysis data sets), as well as other information.
Supporting information: Study protocol, Sap, Csr
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