Safety and Efficacy of the Combination of Tirabrutinib and Entospletinib With and Without Obinutuzumab in Adults With Chronic Lymphocytic Leukemia (CLL)

Study Overview
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Brief Summary
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The primary objective of this study is to determine the preliminary efficacy of the combination of tirabrutinib (formerly GS-4059) and entospletinib with obinutuzumab in adults with relapsed or refractory chronic lymphocytic leukemia (CLL).

Official Title
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A Prospective, Open-Label, Multicenter, Phase 2 Trial to Evaluate the Safety and Efficacy of the Combination of Tirabrutinib (GS-4059) and Entospletinib With and Without Obinutuzumab in Subjects With Chronic Lymphocytic Leukemia

Conditions
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Chronic Lymphocytic Leukemia

Intervention / Treatment
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* Drug: Tirabrutinib
* Drug: Entospletinib
* Drug: Obinutuzumab


Participation Criteria
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Eligibility Criteria
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Key Inclusion Criteria: Documentation of relapsed or refractory CLL Requiring treatment per modified International Workshop on CLL (IWCLL) 2008 criteria; adults without radiographically measureable disease (defined as ≥ 1 lesion > 1.5 centimetres (cm) in diameter as assessed by computed tomography (CT) or magnetic resonance imaging (MRI)) must have bone marrow evaluation at screening Adequate hematologic function: platelet count ≥ 50 × 10^9/liter (L), neutrophil count ≥ 1 × 10^9/L, hemoglobin ≥ 8 grams per deciliter (g/dL) unless lower values are directly attributable to documented bone marrow burden of CLL Creatinine clearance (CrCl) ≥ 50 milliliters per minute (mL/min) Total bilirubin ≤ 1.5× institutional upper limit of normal (ULN) unless attributed to Gilbert's syndrome and aspartate transaminase (AST)/alanine transaminase (ALT) ≤ 2.5×ULN Eastern Cooperative Oncology Group (ECOG) Performance Status (PS) ≤ 2 Absence of active human immunodeficiency virus (HIV), hepatitis B virus (HBV) infection, and hepatitis C virus (HCV) infection Satisfies the following criteria: For females of childbearing potential, willingness to abstain from sexual intercourse or use a protocol-specified method of contraception as described in the study protocol Males of reproductive potential who engage in sexual intercourse must agree to use protocol-specified method(s) of contraception as described in the study protocol Able to comply with study procedures and restrictions Key Exclusion Criteria: Known transformation of CLL (ie, Richter's transformation, prolymphocytic leukemia) Known central nervous system (CNS) involvement Progression on treatment with any inhibitor of Bruton's tyrosine kinase (BTK), spleen tyrosine kinase (SYK), phosphatidylinositol 3-kinase (PI3K), B-cell lymphoma 2 (BCL-2), or obinutuzumab. The treatment and disease response history of participants with prior treatment with agents in these classes should be reviewed by the sponsor or the German CLL Study Group office prior to enrollment to clarify sensitivity to these treatments Any treatment for CLL other than corticosteroids for symptomatic management within 28 days of the start of study treatment Participation on a concurrent therapeutic clinical trial unless all treatment is complete with only ongoing surveillance Diagnosis of or concern for progressive multifocal leukoencephalopathy History of myelodysplastic syndrome or another malignancy other than CLL, except for the following: any malignancy that has been in complete remission for 3 years, adequately treated local basal cell or squamous cell carcinoma of the skin, cervical carcinoma in situ, superficial bladder cancer, asymptomatic prostate cancer without known metastatic disease and with no requirement for therapy or requiring only hormonal therapy and with normal prostate-specific antigen for ≥1 year prior to start of study therapy Active infection requiring systemic therapy Pregnant or nursing women (a negative pregnancy test is required for all women of childbearing potential within 7 days before start of treatment and monthly during therapy) Active autoimmune disease or the need for higher than prednisone 10 mg daily unless for management of CLL symptoms History of stroke or intracranial hemorrhage within 12 months of randomization; participants requiring therapeutic anticoagulation for any indication should be discussed with the German CLL Study Group (GCLLSG) cooperating physician and/or medical monitor prior to screening Anticipated chronic use of strong CYP3A4/CYP2C9 inducers, moderate CYP2C9 inducers, or strong P-gp inducers while on study; use within 2 weeks of first dose of study treatment should be avoided Requirement for proton pump inhibitor (PPI) therapy Demonstration of corrected QT (QTc) interval > 450 milliseconds or requirement for ongoing treatment with concomitant medications that prolong the QT interval Note: Other protocol defined Inclusion/Exclusion criteria may apply.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Tirabrutinib + Entospletinib<br>Participants will receive tirabrutinib 80 mg (4 x 20 mg tablets/2 x 40 mg tablets/1 x 80 mg tablet) + entospletinib 400 mg (2 x 200 mg tablets) for up to 104 weeks. | Drug: Tirabrutinib<br>* Administered orally once daily<br>* Other names: ONO-4059;Drug: Entospletinib<br>* Administered orally once daily<br>* Other names: GS-9973;|
| Experimental: Tirabrutinib + Entospletinib + Obinutuzumab<br>Participants will receive tirabrutinib 80 mg (4 x 20 mg tablets/ 2 x 40 mg tablets/ 1 x 80 mg tablet) + entospletinib 400 mg (2 x 200 mg tablets) for up to 104 weeks + obinutuzumab 100 mg on Day 1, 900 mg on Day 1 or 2, and 1000 mg subsequently for up to 8 doses on Day 1 of Weeks 2, 3, 5, 9, 13, 17 and 21. | Drug: Tirabrutinib<br>* Administered orally once daily<br>* Other names: ONO-4059;Drug: Entospletinib<br>* Administered orally once daily<br>* Other names: GS-9973;Drug: Obinutuzumab<br>* Administered intravenously<br>* Other names: GA101;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Rate of Complete Remission/Complete Remission With Incomplete Recovery of the Bone Marrow (CR/CRi), as Assessed by Investigator Using Modified International Workshop on Chronic Lymphocytic Leukemia (IWCLL) 2008 Criteria at Week 25 | Rate of CR per modified IWCLL 2008 criteria at Week 25 was defined as the percentage of participants who achieved CR/complete remission with incomplete recovery of the bone marrow (CRi) at Week 25. CR: meeting following criteria and no disease related symptoms: no lymphadenopathy > 1.5 cm/hepatomegaly/splenomegaly; lymphocytes < 4000/μL; bone marrow sample must be normocellular with 30% lymphocytes and no B-lymphoid nodules; platelets > 100,000/µL; hemoglobin > 11 g/dL; and neutrophils > 1500/µL. CRi: CR criteria (no lymphadenopathy > 1.5 cm/hepatomegaly/splenomegaly; lymphocytes < 4000/μL; bone marrow [hypocellular] with 30% lymphocytes and no B-lymphoid nodules), persistent anemia/thrombocytopenia/neutropenia unrelated to CLL but related to drug toxicity. | Week 25 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Rate of CR With Bone Marrow Minimal Residual Disease (CR/BM MRD) Negativity, as Assessed by the Investigator Using the Modified IWCLL 2008 Criteria at Week 25 | Rate of CR/BM MRD at Week 25 was defined as percentage of participants who achieved CR/CRi per modified IWCLL 2008 criteria and also achieved BM MRD negativity at Week 25. CR: meeting following criteria and no disease related symptoms: no lymphadenopathy > 1.5 cm/hepatomegaly/splenomegaly; lymphocytes < 4000/μL; bone marrow sample must be normocellular with 30% lymphocytes and no B-lymphoid nodules; platelets > 100,000/µL; hemoglobin > 11 g/dL; and neutrophils > 1500/µL. CRi: CR criteria (no lymphadenopathy > 1.5 cm/hepatomegaly/splenomegaly; lymphocytes < 4000/μL; bone marrow [hypocellular] with 30% lymphocytes and no B-lymphoid nodules), persistent anemia/thrombocytopenia/neutropenia unrelated to CLL but related to drug toxicity. MRD response was assessed with four-color-flow cytometry (FACS) and MRD negativity was defined as one CLL cell per 10,000 leukocytes [0.01%], ie,<10^-4 and participants were defined as MRD negative if their disease burden was below this threshold. | Week 25 | 
| Rate of CR With Peripheral Minimal Residual Disease (CR/PB MRD) Negativity, as Assessed by the Investigator Using the Modified IWCLL 2008 Criteria at Week 25 | Rate of CR/PB MRD at Week 25 was defined as the percentage of participants who achieved CR/CRi per modified IWCLL 2008 criteria and also achieved PB MRD negativity at Week 25. CR: meeting following criteria and no disease related symptoms: no lymphadenopathy > 1.5 cm/hepatomegaly/splenomegaly; lymphocytes < 4000/μL; bone marrow sample must be normocellular with 30% lymphocytes and no B-lymphoid nodules; platelets > 100,000/µL; hemoglobin > 11 g/dL; and neutrophils > 1500/µL. CRi: CR criteria (no lymphadenopathy > 1.5 cm/hepatomegaly/splenomegaly; lymphocytes < 4000/μL; bone marrow [hypocellular] with 30% lymphocytes and no B-lymphoid nodules), persistent anemia/thrombocytopenia/neutropenia unrelated to CLL but related to drug toxicity. MRD response was assessed with FACS and MRD negativity was defined as one CLL cell per 10,000 leukocytes [0.01%], ie,<10^-4 and participants were defined as MRD negative if their disease burden was below this threshold. | Week 25 | 
| Overall Response Rate (ORR), as Assessed by the Investigator Using the Modified IWCLL 2008 Criteria at Week 25 | ORR was assessed based on modified IWCLL 2008 criteria and was defined as percentage of participants achieving a CR, CRi, partial remission (PR; including nodular partial response [nPR]), and PR with lymphocytosis (PR-L). CR and CRi: meeting all the criteria that have been defined in Outcome measures 1, 2 and 3. PR: ≥ 2 of these: ≥ 50% decrease in lymphocytes, lymphadenopathy, size of liver, size of spleen, and 50% decrease in bone marrow infiltrates; and ≥ 1 of these: neutrophils > 1500/μL or ≥ 50% increase from Baseline, platelets ≥ 100,000/µL or ≥ 50% increase from Baseline, hemoglobin >11 g/dL or ≥ 50% increase from Baseline. PR-L: meeting PR criteria; however, a lymphocytosis related to treatment may be present. nPR: All criteria for a CR/CRi were fulfilled, but the bone marrow showed lymphoid nodules. | Week 25 | 
| Percentage of Participants Experiencing Any Treatment-Emergent Adverse Events (AEs) and Treatment-Emergent Serious Adverse Events (SAEs) | A treatment emergent AE is defined as an AE that occurs or worsens in severity on or after the date of the first dose of study drug but no later than 30 days after the permanent discontinuation of study drug or an AE leading to discontinuation of study drug. A SAE is defined as an event that, at any dose, resulted in any of the following: death, life-threatening, in-patient hospitalization or prolongation of existing hospitalization, persistent or significant disability/incapacity, a congenital anomaly/birth defect, or a medically important event or reaction. | First dose date up to the last dose date (maximum: 105.9 weeks) plus 30 days |