June 10, 2022
AbbVie Presents Investigational Navitoclax Preliminary Data in JAK Inhibitor Naïve Myelofibrosis Patients
  • Data is supportive of early intervention in myelofibrosis to achieve improved clinical outcomes in spleen volume reduction (SVR), symptom score, bone marrow fibrosis (BMF), and anemia
  • Results are from an exploratory analysis of navitoclax plus ruxolitinib from Cohort 3 of the Phase 2 REFINE study in JAK inhibitor naïve myelofibrosis patients

NORTH CHICAGO, Ill., June 10, 2022 /PRNewswire/ -- AbbVie (NYSE: ABBV) today announced new data from Cohort 3 of its Phase 2 REFINE study of investigational navitoclax in combination with ruxolitinib in JAK inhibitor naïve patients with myelofibrosis (MF), a rare and difficult to treat blood cancer. These preliminary findings show spleen volume and symptomatic improvement in this cohort. These data are consistent with previously observed data from relapsed/refractory patients in Cohort 1a1 and will be shared in an oral presentation at the 2022 European Hematology Association (EHA) Annual Congress (Abstract #S197).2

REFINE is a Phase 2 non-randomized open-label multi-cohort study evaluating the safety and efficacy of navitoclax alone or in combination with ruxolitinib in MF.

"Current treatment options for myelofibrosis are limited and targeted toward controlling disease symptoms," said Mohamed Zaki, M.D., Ph.D., vice president and global head of oncology clinical development, AbbVie. "Together with pre-clinical findings, early results of this study demonstrating anti-fibrosis activity of navitoclax in combination with ruxolitinib are promising. Specifically, the data findings regarding reduction in spleen volume, symptoms and bone marrow fibrosis help support the further exploration of disease modification in myelofibrosis."

The results presented at EHA 2022 were from a preliminary analysis of 32 JAK inhibitor naïve MF patients from Cohort 3 of the Phase 2 REFINE trial (NCT03222609).2 The primary endpoint was spleen volume reduction of ≥35 percent (SVR35) from baseline at week 24.2 Key secondary endpoints include ≥50 percent reduction in total symptom score (TSS50) at week 24, anemia response and BMF reduction.2

In the results, SVR35 was achieved by 63 percent of evaluable patients at week 24 (20/32) and by 78 percent at any time on treatment (25/32).2 At week 24, 41 percent (11/27) of evaluable patients with measurable baseline symptoms reached TSS50; notably, 67 percent of patients (18/27) met this endpoint at any time during the study.2 In this cohort, 35 percent of evaluable patients, with available fibrosis grade at baseline and during the study, (9/26) achieved reduction in BMF by ≥1 grade at any time during the study with three patients experiencing ≥2 grade reductions in BMF.2 Additionally, 40 percent of patients evaluable for anemia response (6/15) experienced improvement in anemia, a common clinical feature of MF.2 

Preliminary safety analysis identified no new safety signals. Thirty-one (97 percent) patients reported one or more adverse event (AE).1 The most common Grade ≥3 AEs were thrombocytopenia (47 percent), anemia (34 percent), and neutropenia (25 percent).1 Seven patients (22 percent) reported experiencing serious AEs.1 Three patients (9 percent) experienced an AE leading to navitoclax discontinuation and three patients (9 percent) reported an AE leading to ruxolitinib discontinuation.2  

"These data reinforce the importance of early intervention in myelofibrosis and the potential to achieve improved clinical outcomes," said Francesco Passamonti, Full Professor of Hematology, University of Insubria and Chief, Hematology, Varee Hospital. "These preliminary results show good responses to combination therapy with navitoclax that may continue to improve over time."

About Navitoclax
Navitoclax is an investigational, oral BCL-XL/BCL-2 inhibitor. The BCL-2 family of proteins are known regulators of the apoptosis pathway.3

Navitoclax is not approved by the U.S. Food and Drug Administration (FDA) or any Health Authority worldwide at this time. Its safety and efficacy are under evaluation as part of ongoing Phase 2 and registrational Phase 3 studies.

AbbVie has an extensive late-stage clinical trial program for investigational navitoclax that is currently enrolling. For more information about enrolling in a clinical trial, please visit us here.   

About the REFINE Study
REFINE is a multi-cohort, Phase 2, randomized, open-label, multicenter study evaluating the tolerability and efficacy of navitoclax alone or when added to ruxolitinib in patients with myelofibrosis (MF).4 The primary outcome measure is the percentage of patients who achieve Spleen Volume Reduction of greater than or equal to 35 percent (SVR35) from baseline to Week 24. Secondary outcomes measures include percentage of participants achieving 50 percent reduction in Total Symptom Score from baseline to Week 24 and change in grade of bone marrow fibrosis assessed according to the European Consensus Grading System.

Data presented at EHA 2022 include preliminary safety and efficacy results from Cohort 3 of REFINE (n=32). Patients in Cohort 3 had primary or secondary MF with splenomegaly and had not received JAK-2 therapy or BET inhibitors prior to enrollment. Data presented at EHA 2022 are representative of data from Cohort 3 of the REFINE study as of February 7, 2022.

Data included in the official EHA 2022 Abstract Book are representative of data from Cohort 3 of the REFINE study as of October 4, 2021. 

More information can be found on (NCT03222609).

About Myelofibrosis
Myelofibrosis (MF) is a rare, difficult-to-treat blood cancer that results in excessive scar tissue formation (fibrosis) in the bone marrow. Patients living with MF experience symptoms such as an enlarged spleen, fatigue, weakness, and severe anemia, that are often debilitating and greatly impact quality of life. MF also carries a risk of transformation to more aggressive disease such as acute myeloid leukemia.4

About AbbVie in Oncology
At AbbVie, we are committed to transforming standards of care for multiple blood cancers while advancing a dynamic pipeline of investigational therapies across a range of cancer types. Our dedicated and experienced team joins forces with innovative partners to accelerate the delivery of potentially breakthrough medicines. We are evaluating more than 20 investigational medicines in over 300 clinical trials across some of the world's most widespread and debilitating cancers. As we work to have a remarkable impact on people's lives, we are committed to exploring solutions to help patients obtain access to our cancer medicines. For more information, please visit

About AbbVie
AbbVie's mission is to discover and deliver innovative medicines that solve serious health issues today and address the medical challenges of tomorrow. We strive to have a remarkable impact on people's lives across several key therapeutic areas: immunology, oncology, neuroscience, eye care, virology, women's health and gastroenterology, in addition to products and services across its Allergan Aesthetics portfolio. For more information about AbbVie, please visit us at Follow @abbvie on TwitterFacebook, InstagramYouTube and LinkedIn.

Forward-Looking Statements
Some statements in this news release are, or may be considered, forward-looking statements for purposes of the Private Securities Litigation Reform Act of 1995. The words "believe," "expect," "anticipate," "project" and similar expressions, among others, generally identify forward-looking statements. AbbVie cautions that these forward-looking statements are subject to risks and uncertainties that may cause actual results to differ materially from those indicated in the forward-looking statements. Such risks and uncertainties include, but are not limited to, failure to realize the expected benefits from AbbVie's acquisition of Allergan plc ("Allergan"), failure to promptly and effectively integrate Allergan's businesses, competition from other products, challenges to intellectual property, difficulties inherent in the research and development process, adverse litigation or government action, changes to laws and regulations applicable to our industry and the impact of public health outbreaks, epidemics or pandemics, such as COVID-19. Additional information about the economic, competitive, governmental, technological and other factors that may affect AbbVie's operations is set forth in Item 1A, "Risk Factors," of AbbVie's 2021 Annual Report on Form 10-K, which has been filed with the Securities and Exchange Commission, as updated by its subsequent Quarterly Reports on Form 10-Q. AbbVie undertakes no obligation to release publicly any revisions to forward-looking statements as a result of subsequent events or developments, except as required by law.


  1. Ruxolitinib with Navitoclax Is Efficacious and Safe in Myelofibrosis. Cancer Discovery 1 May 2022; 12 (5): OF4.
  2. Navitoclax plus ruxolitinib in JAK inhibitor-naïve patients with myelofibrosis: Preliminary safety and efficacy in a multicenter, open-label Phase 2 study. [Oral Presentation S197]. Presented at European Hematology Association 2022 Congress (EHA 2022), June 9-12, 2022.
  3. Harrison C, Garcia J, Somervaille T, et al. Addition of Navitoclax to Ongoing Ruxolitinib Therapy for Patients With Myelofibrosis With Progression or Suboptimal Response: Phase II Safety and Efficacy. J Clin Oncol. 2022; JCO2102188.
  4. Tsujimoto Y. (1998). Role of Bcl-2 family proteins in apoptosis: apoptosomes or mitochondria?. Genes to cells: devoted to molecular & cellular mechanisms, 3(11), 697–707. 


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