Trial Outcomes & Findings for Study of Oral Navitoclax Tablet In Combination With Oral Ruxolitinib Tablet When Compared With Oral Ruxolitinib Tablet To Assess Change In Spleen Volume In Adult Participants With Myelofibrosis (NCT NCT04472598)

Last Updated: 2026-03-23

Results Overview

Reduction in spleen volume is measured by magnetic resonance imaging (MRI) or computed tomography (CT), per International Working Group (IWG) criteria.

Recruitment status

COMPLETED

Study phase

PHASE3

Target enrollment

252 participants

Primary outcome timeframe

Baseline, Week 24

Results posted on

2026-03-23

Participant Flow

This trial was conducted in 24 countries.

Participants were randomized in a 1:1 ratio to one of two treatment arms, with stratification factors of intermediate-2 versus high risk (Dynamic International Prognostic Scoring System Plus \[DIPSS+\]) 1 and platelet count ≤ 200 × 10\^9 /L versus \> 200 × 10\^9 /L: Control group: Placebo for Navitoclax + Ruxolitinib; Experimental group: Navitoclax + Ruxolitinib

Participant milestones

Participant milestones
Measure	Placebo for Navitoclax + Ruxolitinib 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).	Navitoclax + 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).
Overall Study STARTED	127	125
Overall Study COMPLETED	0	0
Overall Study NOT COMPLETED	127	125

Reasons for withdrawal

Reasons for withdrawal
Measure	Placebo for Navitoclax + Ruxolitinib 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).	Navitoclax + 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).
Overall Study Lost to Follow-up	1	2
Overall Study Death	28	35
Overall Study Withdrew consent	15	7
Overall Study Other, not specified	83	81

Baseline Characteristics

Study of Oral Navitoclax Tablet In Combination With Oral Ruxolitinib Tablet When Compared With Oral Ruxolitinib Tablet To Assess Change In Spleen Volume In Adult Participants With Myelofibrosis

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Placebo for Navitoclax + Ruxolitinib n=127 Participants 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).	Navitoclax + Ruxolitinib n=125 Participants 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).	Total n=252 Participants Total of all reporting groups
Age, Continuous	68.5 years STANDARD_DEVIATION 8.49 • n=10 Participants	68.7 years STANDARD_DEVIATION 9.17 • n=8 Participants	68.6 years STANDARD_DEVIATION 8.81 • n=18 Participants
Sex: Female, Male Female	46 Participants n=10 Participants	62 Participants n=8 Participants	108 Participants n=18 Participants
Sex: Female, Male Male	81 Participants n=10 Participants	63 Participants n=8 Participants	144 Participants n=18 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	8 Participants n=10 Participants	7 Participants n=8 Participants	15 Participants n=18 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	119 Participants n=10 Participants	118 Participants n=8 Participants	237 Participants n=18 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	0 Participants n=10 Participants	0 Participants n=8 Participants	0 Participants n=18 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=10 Participants	0 Participants n=8 Participants	0 Participants n=18 Participants
Race (NIH/OMB) Asian	26 Participants n=10 Participants	24 Participants n=8 Participants	50 Participants n=18 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	1 Participants n=10 Participants	0 Participants n=8 Participants	1 Participants n=18 Participants
Race (NIH/OMB) Black or African American	1 Participants n=10 Participants	1 Participants n=8 Participants	2 Participants n=18 Participants
Race (NIH/OMB) White	99 Participants n=10 Participants	100 Participants n=8 Participants	199 Participants n=18 Participants
Race (NIH/OMB) More than one race	0 Participants n=10 Participants	0 Participants n=8 Participants	0 Participants n=18 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=10 Participants	0 Participants n=8 Participants	0 Participants n=18 Participants

PRIMARY outcome

Timeframe: Baseline, Week 24

Population: Intent-to-Treat population: all randomized participants analyzed by the treatment arm assigned at the time of randomization

Reduction in spleen volume is measured by magnetic resonance imaging (MRI) or computed tomography (CT), per International Working Group (IWG) criteria.

Outcome measures

Outcome measures
Measure	Placebo for Navitoclax + Ruxolitinib n=127 Participants 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).	Navitoclax + Ruxolitinib n=125 Participants 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).
Percentage of Participants With ≥ 35% Reduction From Baseline in Spleen Volume at Week 24 (SVR35W24)	31.50 percentage of participants Interval 23.55 to 40.33	63.20 percentage of participants Interval 54.11 to 71.65

SECONDARY outcome

Timeframe: Baseline, Week 24

Population: Intent-to-Treat population: all randomized participants analyzed by the treatment arm assigned at the time of randomization

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.

Outcome measures

Outcome measures
Measure	Placebo for Navitoclax + Ruxolitinib n=127 Participants 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).	Navitoclax + Ruxolitinib n=125 Participants 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).
Change From Baseline in Total Symptom Score (TSS) at Week 24 as Measured by Myelofibrosis Symptom Assessment Form (MFSAF) v4.0	-11.14 units on a scale Interval -13.23 to -9.05	-9.71 units on a scale Interval -11.8 to -7.62

SECONDARY outcome

Timeframe: Up to Week 97

Population: Intent-to-Treat population: all randomized participants analyzed by the treatment arm assigned at the time of randomization

Reduction in spleen volume is measured by magnetic resonance imaging (MRI) or computed tomography (CT), per International Working Group (IWG) criteria.

Outcome measures

Outcome measures
Measure	Placebo for Navitoclax + Ruxolitinib n=127 Participants 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).	Navitoclax + Ruxolitinib n=125 Participants 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).
Percentage of Participants With ≥ 35% Reduction From Baseline in Spleen Volume (SVR35) at Any Time	44.09 percentage of participants Interval 35.3 to 53.17	76.80 percentage of participants Interval 68.41 to 83.88

SECONDARY outcome

Timeframe: Baseline (Week 0) Up to Month 48

Population: Intent-to-Treat population: all randomized participants analyzed by the treatment arm assigned at the time of randomization; only participants who achieve SVR35 are included in the analysis

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.

Outcome measures

Outcome measures
Measure	Placebo for Navitoclax + Ruxolitinib n=56 Participants 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).	Navitoclax + Ruxolitinib n=96 Participants 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).
Duration of 35% Spleen Volume Reduction (SVR35)	NA months Interval 19.38 to Not calculable/estimable due to low number of events	NA months Interval 27.6 to Not calculable/estimable due to low number of events

SECONDARY outcome

Timeframe: Baseline, Week 24

Population: Intent-to-Treat population: all randomized participants analyzed by the treatment arm assigned at the time of randomization; only participants with both Baseline and Week 24 score are included in the analysis

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.

Outcome measures

Outcome measures
Measure	Placebo for Navitoclax + Ruxolitinib n=99 Participants 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).	Navitoclax + Ruxolitinib n=104 Participants 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).
Change From Baseline In Fatigue at Week 24 as Measured by the PROMIS Fatigue Short Form (SF) 7a	-3.63 T-Score Interval -5.38 to -1.88	-3.75 T-Score Interval -5.46 to -2.04

SECONDARY outcome

Timeframe: Baseline, Week 24

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.

Outcome measures

Outcome measures
Measure	Placebo for Navitoclax + Ruxolitinib n=95 Participants 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).	Navitoclax + Ruxolitinib n=99 Participants 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).
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 units on a scale Interval 2.238 to 10.158	7.326 units on a scale Interval 3.458 to 11.195

SECONDARY outcome

Timeframe: Up to Week 97

Population: Intent-to-Treat population: all randomized participants analyzed by the treatment arm assigned at the time of randomization; participants who were Baseline transfusion independent with Baseline hemoglobin of ≥10 g/dL were excluded from the analysis since they were not evaluable for 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.

Outcome measures

Outcome measures
Measure	Placebo for Navitoclax + Ruxolitinib n=72 Participants 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).	Navitoclax + Ruxolitinib n=66 Participants 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).
Percentage of Participants Achieving Anemia Response Overall	30.56 percentage of participants Interval 20.24 to 42.53	28.79 percentage of participants Interval 18.3 to 41.25
Percentage of Participants Achieving Anemia Response Baseline transfusion independent with Baseline Hb <10 g/dL	29.41 percentage of participants Interval 18.98 to 41.71	29.51 percentage of participants Interval 18.52 to 42.57
Percentage of Participants Achieving Anemia Response Baseline transfusion dependent	50.00 percentage of participants Interval 6.76 to 93.24	20.00 percentage of participants Interval 0.51 to 71.64

SECONDARY outcome

Timeframe: Up to 50 months

Population: Intent-to-Treat population: all randomized participants analyzed by the treatment arm assigned at the time of randomization

OS is defined as the time from the date of randomization to the date of death from any cause.

Outcome measures

Outcome measures
Measure	Placebo for Navitoclax + Ruxolitinib n=127 Participants 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).	Navitoclax + Ruxolitinib n=125 Participants 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).
Overall Survival (OS)	48.49 months Interval 48.49 to Not calculable/estimable due to low number of events	NA months Interval 41.36 to Not calculable/estimable due to low number of events

SECONDARY outcome

Timeframe: Up to 50 months

Population: Intent-to-Treat population: all randomized participants analyzed by the treatment arm assigned at the time of randomization

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.

Outcome measures

Outcome measures
Measure	Placebo for Navitoclax + Ruxolitinib n=127 Participants 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).	Navitoclax + Ruxolitinib n=125 Participants 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).
Leukemia-Free Survival	NA months Interval 40.05 to Not calculable/estimable due to low number of events	NA months Interval 37.62 to Not calculable/estimable due to low number of events

SECONDARY outcome

Timeframe: Up to Week 97

Population: Intent-to-Treat population: all randomized participants analyzed by the treatment arm assigned at the time of randomization; participants who have a bone marrow fibrosis grade determined at Baseline and at least one post-Baseline assessment are included in the analysis

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.

Outcome measures

Outcome measures
Measure	Placebo for Navitoclax + Ruxolitinib n=90 Participants 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).	Navitoclax + Ruxolitinib n=92 Participants 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).
Percentage of Participants Who Achieved Reduction in Grade of Bone Marrow Fibrosis From Baseline at Any Time	48.89 percentage of participants Interval 38.2 to 59.65	56.52 percentage of participants Interval 45.78 to 66.83

Adverse Events

Placebo for Navitoclax + Ruxolitinib

Serious events: 56 serious events

Other events: 115 other events

Deaths: 28 deaths

Navitoclax + Ruxolitinib

Serious events: 42 serious events

Other events: 121 other events

Deaths: 35 deaths

Serious adverse events

Other adverse events

Additional Information

Global Medical Services

AbbVie

Phone: 800-633-9110

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee AbbVie requests that any investigator or institution that plans on presenting/publishing results disclosure, provide written notification of their request 60 days prior to their presentation/publication. AbbVie requests that no presentation/publication will be instituted until 12 months after a study is completed, or after the first presentation/publication whichever occurs first. A delay may be proposed of a presentation/publication if AbbVie needs to secure patent or proprietary protection.
Publication restrictions are in place

Restriction type: OTHER