A Study Evaluating Tolerability and Efficacy of Navitoclax Alone or in Combination With Ruxolitinib in Participants With Myelofibrosis (REFINE)

AbbVie

Status and phase: Completed; Phase 2

Conditions: Myelofibrosis (MF)

Treatments: Drug: Navitoclax; Drug: Ruxolitinib

Study type: Interventional

Funder types: Industry

Identifiers

NCT03222609

2017-001398-17 (EudraCT Number)

M16-109

Details and patient eligibility

About

This is a Phase 2 open-label, multicenter study evaluating tolerability and efficacy of navitoclax alone or when added to ruxolitinib in participants with myelofibrosis.

Safety and efficacy data through 16 January 2023 are included in the interim analysis.

Enrollment: 191 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Participants with documented diagnosis of intermediate-2 or high-risk primary Myelofibrosis, Post Polycythemia Vera Myelofibrosis or Post-essential Thrombocythemia Myelofibrosis.

• Participant must be ineligible due to age, comorbidities, or unfit for unrelated or unmatched donor transplantation or unwilling to undergo stem cell transplantation at time of study entry.

• Eastern Cooperative Oncology Group (ECOG) of 0, 1, or 2.

• Prior treatment must meet at least one of the following criteria:

  • Prior or current treatment with ruxolitinib and no prior treatment with a Bromodomain and Extra-Terminal motif (BET) proteins inhibitor or another Janus Kinase 2 (JAK-2) inhibitor, and meet all of the following criteria:

    • Ruxolitinib treatment must meet at least one of the following criteria:

      • Ruxolitinib treatment for >=24 weeks with lack of efficacy defined as a lack of spleen response (refractory) or a loss of spleen or symptom response (relapsed)
      • Ruxolitinib treatment for <24 weeks with documented disease progression on spleen measurements while on ruxolitinib as defined in the protocol:
      • Ruxolitinib treatment for >=28 days with intolerance defined as new red blood cell transfusion requirement (at least 2 units/month for 2 months) while receiving a total daily ruxolitinib dose of >=30 mg but unable to reduce dose further due to lack of efficacy.

    • If receiving ruxolitinib at the time of screening, must currently be on a stable dose >=10 mg twice daily of ruxolitinib for >=4 weeks prior to the 1st dose of navitoclax.

    • Participant has at least 2 symptoms each with a score >=3 or a total score of >=12, as measured by the Myelofibrosis Symptom Assessment Form (MFSAF) v4.0 on at least 4 out of 7 days during screening prior to study drug dosing; OR

  • Prior treatment with a JAK-2 inhibitor and meet one of the following criteria:

    • Prior treatment with a JAK-2 inhibitor for at least 12 weeks
    • Prior treatment with a JAK-2 inhibitor for >=28 days complicated by either development of red blood cell transfusion requirement (at least 2 units/month for 2 months) OR Grade >= 3 adverse events of thrombocytopenia, anemia, hematoma and/or hemorrhage while on JAK-2 inhibitor treatment; OR

  • No prior treatment with a JAK-2 or BET inhibitor.

• Participant has splenomegaly as defined in the protocol.

• Participant must meet the laboratory parameters (adequate bone marrow, renal and hepatic function) as defined in the protocol.

Exclusion criteria

• Splenic irradiation within 6 months prior to screening, or prior splenectomy.
• Leukemic transformation (> 10% blasts in peripheral blood or bone marrow aspirate/biopsy).
• Participant is currently on medications that interfere with coagulation (including warfarin) or platelet function within 3 days prior to the first dose of study drug or during the study treatment period with the exception of low dose aspirin (up to 100 mg/day) and low-molecular-weight heparin.
• Prior therapy with a BH3 mimetic compound or stem cell transplantation.
• Participant has received strong CYP3A inhibitors (e.g., ketoconazole, clarithromycin) or moderate CYP3A inhibitors (e.g., fluconazole) within 14 days prior to the administration of the first dose of study drug.

Trial design

Primary purpose: Treatment

Allocation: Non-Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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191 participants in 4 patient groups

Navitoclax + ruxolitinib (Cohort 1a)

Experimental group

Description:

Participants must have received ruxolitinib for at least 12 weeks and on stable dose of ≥10 mg tablets orally twice daily (BID) for ≥8 weeks prior to the 1st dose of navitoclax. Navitoclax tablets are administered once daily (QD) at a starting dose of 50 mg. This was increased after approximately ≥7 days to next dose level if platelet count is ≥75 × 10\^9/L up to a maximum dose of navitoclax 300 mg QD. Participants will continue their treatment until end of clinical benefit, unacceptable toxicity, or they meet other protocol criteria for discontinuation (whichever occurs first).

Treatment:

Drug: Ruxolitinib

Drug: Navitoclax

Navitoclax + ruxolitinib (Cohort 1b)

Experimental group

Description:

Those receiving ruxolitinib at Screening must be on a stable dose ≥10 mg tablets orally twice daily (BID) for ≥ 4 weeks prior to 1st dose of navitoclax. Those not receiving ruxolitinib at Screening received 10 mg ruxolitinib BID starting on Day 1. 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 24 disease assessment, navitoclax dose was increased to 300 mg QD at discretion of the Investigator for those with suboptimal spleen response defined as failure to achieve spleen volume reduction of at least 10% per imaging. Participants will continue their treatment until end of clinical benefit, unacceptable toxicity, or they meet other protocol criteria for discontinuation (whichever occurs first).

Treatment:

Drug: Ruxolitinib

Drug: Navitoclax

Navitoclax (Cohort 2)

Experimental group

Description:

Participants must have received prior treatment with a Janus Kinase 2 (JAK-2) inhibitor. Those with Baseline platelet count \>150 × 10\^9/L initiated navitoclax film-coated tablets orally once daily (QD) at the starting dose of 200 mg. Those with a Baseline platelet count ≤150 × 10\^9/L initiated navitoclax film-coated tablets orally once daily (QD) at the starting dose of 100 mg, which could be increased to 200 mg once daily after 7 days provided the platelet count is ≥75 × 10\^9/L. Navitoclax didn't exceed 200 mg QD for the first 24 weeks of treatment. After Week 24 disease assessment, navitoclax dose may be increased to 300 mg QD at discretion of the Investigator for those with suboptimal spleen response defined as failure to achieve spleen volume reduction of at least 10% per imaging. Participants will continue their treatment until end of clinical benefit, unacceptable toxicity, or they meet other protocol criteria for discontinuation (whichever occurs first).

Treatment:

Drug: Navitoclax

Navitoclax + ruxolitinib (Cohort 3)

Experimental group

Description:

Prior treatment with a Janus Kinase 2 (JAK-2) or Bromodomain and Extra-Terminal motif (BET) proteins inhibitor was prohibited. Ruxolitinib tablets administered orally twice daily (BID) based on Baseline platelet count as per the local approved label. 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 24 disease assessment, navitoclax dose may be increased to 300 mg QD at discretion of Investigator for those with suboptimal spleen response defined as failure to achieve spleen volume reduction of at least 10% per imaging. Participants will continue their treatment until end of clinical benefit, unacceptable toxicity, or they meet other protocol criteria for discontinuation (whichever occurs first).

Treatment:

Drug: Ruxolitinib

Drug: Navitoclax