A Study of Multiple Immunotherapy-Based Treatment Combinations in Hormone Receptor (HR)-Positive Human Epidermal Growth Factor Receptor 2 (HER2)-Negative Breast Cancer (MORPHEUS HR+BC)
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ClinicalTrials.gov Identifier: NCT03280563 |
Recruitment Status :
Active, not recruiting
First Posted : September 12, 2017
Last Update Posted : March 22, 2023
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Condition or disease | Intervention/treatment | Phase |
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Breast Neoplasms | Drug: Atezolizumab (MPDL3280A), an engineered anti-programmed death-ligand 1 (PD-L1) antibody Drug: Bevacizumab Drug: Entinostat Drug: Exemestane Drug: Fulvestrant Drug: Ipatasertib Drug: Tamoxifen Drug: Abemaciclib | Phase 1 Phase 2 |
Study Type : | Interventional (Clinical Trial) |
Actual Enrollment : | 138 participants |
Allocation: | Randomized |
Intervention Model: | Sequential Assignment |
Masking: | None (Open Label) |
Primary Purpose: | Treatment |
Official Title: | A Phase Ib/II, Open-Label, Multicenter, Randomized Umbrella Study Evaluating the Efficacy and Safety of Multiple Immunotherapy-Based Treatment Combinations in Patients With Hormone Receptor-Positive HER2-Negative Breast Cancer (MORPHEUS-HR+ Breast Cancer) |
Actual Study Start Date : | December 26, 2017 |
Estimated Primary Completion Date : | December 31, 2023 |
Estimated Study Completion Date : | December 31, 2023 |

Arm | Intervention/treatment |
---|---|
Active Comparator: Stage 1: Fulvestrant
Participants will receive fulvestrant until unacceptable toxicity or disease progression according to RECIST v1.1.
|
Drug: Fulvestrant
Fulvestrant will be given as 500 mg intramuscularly on Days 1 and 15 of Cycle 1 and thereafter on Day 1 of each 28-day cycle. |
Experimental: Stage 1: Atezolizumab + Entinostat
Participants will receive doublet combination treatment with atezolizumab plus entinostat until unacceptable toxicity or loss of clinical benefit as determined by the investigator.
|
Drug: Atezolizumab (MPDL3280A), an engineered anti-programmed death-ligand 1 (PD-L1) antibody
Atezolizumab will be given as 840 milligrams (mg) via intravenous (IV) infusion on Days 1 and 15 of each 28-day cycle. This regimen will apply to all arms except when given with entinostat in Stage 1, or exemestane or tamoxifen in Stage 2, in which atezolizumab will be given as 1200 mg via IV infusion on Day 1 of each 21-day cycle.
Other Name: Tecentriq Drug: Entinostat Entinostat will be given as 5 mg orally once a week on Days 1, 8 and 15 of each 21-day cycle. |
Experimental: Stage 1: Atezolizumab + Fulvestrant
Participants will receive doublet combination treatment with atezolizumab plus fulvestrant until unacceptable toxicity or loss of clinical benefit as determined by the investigator.
|
Drug: Atezolizumab (MPDL3280A), an engineered anti-programmed death-ligand 1 (PD-L1) antibody
Atezolizumab will be given as 840 milligrams (mg) via intravenous (IV) infusion on Days 1 and 15 of each 28-day cycle. This regimen will apply to all arms except when given with entinostat in Stage 1, or exemestane or tamoxifen in Stage 2, in which atezolizumab will be given as 1200 mg via IV infusion on Day 1 of each 21-day cycle.
Other Name: Tecentriq Drug: Fulvestrant Fulvestrant will be given as 500 mg intramuscularly on Days 1 and 15 of Cycle 1 and thereafter on Day 1 of each 28-day cycle. |
Experimental: Stage 1: Atezolizumab + Ipatasertib
Participants will receive doublet combination treatment with atezolizumab plus ipatasertib until unacceptable toxicity or loss of clinical benefit as determined by the investigator. Prior to enrollment into this arm, the first 6 participants in the study will complete a safety run-in with atezolizumab plus ipatasertib.
|
Drug: Atezolizumab (MPDL3280A), an engineered anti-programmed death-ligand 1 (PD-L1) antibody
Atezolizumab will be given as 840 milligrams (mg) via intravenous (IV) infusion on Days 1 and 15 of each 28-day cycle. This regimen will apply to all arms except when given with entinostat in Stage 1, or exemestane or tamoxifen in Stage 2, in which atezolizumab will be given as 1200 mg via IV infusion on Day 1 of each 21-day cycle.
Other Name: Tecentriq Drug: Ipatasertib Ipatasertib will be given as 400 mg orally QD on Days 1-21 of each 28-day cycle. |
Experimental: Stage 1: Atezolizumab + Ipatasertib + Fulvestrant
Participants will receive triplet combination treatment with atezolizumab plus ipatasertib plus fulvestrant until unacceptable toxicity or loss of clinical benefit as determined by the investigator. Prior to enrollment into this arm, the first 6 participants in the study will complete a safety run-in with atezolizumab plus ipatasertib.
|
Drug: Atezolizumab (MPDL3280A), an engineered anti-programmed death-ligand 1 (PD-L1) antibody
Atezolizumab will be given as 840 milligrams (mg) via intravenous (IV) infusion on Days 1 and 15 of each 28-day cycle. This regimen will apply to all arms except when given with entinostat in Stage 1, or exemestane or tamoxifen in Stage 2, in which atezolizumab will be given as 1200 mg via IV infusion on Day 1 of each 21-day cycle.
Other Name: Tecentriq Drug: Fulvestrant Fulvestrant will be given as 500 mg intramuscularly on Days 1 and 15 of Cycle 1 and thereafter on Day 1 of each 28-day cycle. Drug: Ipatasertib Ipatasertib will be given as 400 mg orally QD on Days 1-21 of each 28-day cycle. |
Experimental: Stage 2: Atezolizumab + Bevacizumab + Endocrine Therapy
Those who progress or experience unacceptable toxicity during treatment in Stage 1 may be eligible to enter Stage 2. Participants will receive triplet combination therapy with atezolizumab plus bevacizumab plus one of three endocrine therapies (fulvestrant, exemestane, or tamoxifen) selected by the physician. Treatment in Stage 2 will continue until unacceptable toxicity or loss of clinical benefit as determined by the investigator.
|
Drug: Atezolizumab (MPDL3280A), an engineered anti-programmed death-ligand 1 (PD-L1) antibody
Atezolizumab will be given as 840 milligrams (mg) via intravenous (IV) infusion on Days 1 and 15 of each 28-day cycle. This regimen will apply to all arms except when given with entinostat in Stage 1, or exemestane or tamoxifen in Stage 2, in which atezolizumab will be given as 1200 mg via IV infusion on Day 1 of each 21-day cycle.
Other Name: Tecentriq Drug: Bevacizumab Bevacizumab will be given as 10 milligrams per kilogram (mg/kg) via IV infusion on Days 1 and 15 of each 28-day cycle in the regimen containing fulvestrant. When given with exemestane or tamoxifen, bevacizumab will be given as 15 mg/kg via IV infusion on Day 1 of each 21-day cycle.
Other Name: Avastin Drug: Exemestane Exemestane will be given as 25 mg orally QD in each 21-day cycle. Drug: Fulvestrant Fulvestrant will be given as 500 mg intramuscularly on Days 1 and 15 of Cycle 1 and thereafter on Day 1 of each 28-day cycle. Drug: Tamoxifen Tamoxifen will be given as 20 mg orally QD in each 21-day cycle. |
Experimental: Stage 1: Mandatory On-Treatment Biopsy
For experimental combination arms that demonstrate clinical activity during the preliminary phase, the Sponsor may open enrollment into a separate mandatory on-treatment biopsy cohort for that combination.
|
Drug: Atezolizumab (MPDL3280A), an engineered anti-programmed death-ligand 1 (PD-L1) antibody
Atezolizumab will be given as 840 milligrams (mg) via intravenous (IV) infusion on Days 1 and 15 of each 28-day cycle. This regimen will apply to all arms except when given with entinostat in Stage 1, or exemestane or tamoxifen in Stage 2, in which atezolizumab will be given as 1200 mg via IV infusion on Day 1 of each 21-day cycle.
Other Name: Tecentriq Drug: Entinostat Entinostat will be given as 5 mg orally once a week on Days 1, 8 and 15 of each 21-day cycle. Drug: Fulvestrant Fulvestrant will be given as 500 mg intramuscularly on Days 1 and 15 of Cycle 1 and thereafter on Day 1 of each 28-day cycle. Drug: Ipatasertib Ipatasertib will be given as 400 mg orally QD on Days 1-21 of each 28-day cycle. Drug: Abemaciclib Abemaciclib will be given as 150mg twice daily during each 28-day cycle. |
Experimental: Stage 1: Atezolizumab + Abemaciclib + Fulvestrant
Participants will receive triplet combination treatment with atezolizumab plus abemaciclib plus fulvestrant until unacceptable toxicity or loss of clinical benefit as determined by the investigator.
|
Drug: Atezolizumab (MPDL3280A), an engineered anti-programmed death-ligand 1 (PD-L1) antibody
Atezolizumab will be given as 840 milligrams (mg) via intravenous (IV) infusion on Days 1 and 15 of each 28-day cycle. This regimen will apply to all arms except when given with entinostat in Stage 1, or exemestane or tamoxifen in Stage 2, in which atezolizumab will be given as 1200 mg via IV infusion on Day 1 of each 21-day cycle.
Other Name: Tecentriq Drug: Fulvestrant Fulvestrant will be given as 500 mg intramuscularly on Days 1 and 15 of Cycle 1 and thereafter on Day 1 of each 28-day cycle. Drug: Abemaciclib Abemaciclib will be given as 150mg twice daily during each 28-day cycle. |
- Percentage of Participants with Objective Response during Stage 1 According to Response Evaluation Criteria in Solid Tumors (RECIST) Version (v) 1.1 [ Time Frame: From baseline until disease progression or loss of clinical benefit (up to 6 years overall) ]
- Progression-Free Survival during Stage 1 According to RECIST v1.1 [ Time Frame: From randomization until disease progression or death from any cause (up to 6 years overall) ]
- Percentage of Participants with Clinical Benefit during Stage 1 According to RECIST v1.1 [ Time Frame: From baseline until disease progression or loss of clinical benefit (up to 6 years overall) ]
- Overall Survival during Stage 1 [ Time Frame: From randomization until death from any cause (up to 6 years overall) ]
- Percentage of Participants Alive at 18 Months during Stage 1 [ Time Frame: 18 months ]
- Duration of Response during Stage 1 According to RECIST v1.1 [ Time Frame: From first objective response until disease progression or death from any cause (up to 6 years overall) ]
- Percentage of Participants with Adverse Events (AEs) during Stage 1 [ Time Frame: From baseline until 30 days after last dose or initiation of new systemic anti-cancer therapy (up to 6 years overall) ]
- Percentage of Participants with AEs during Stage 2 [ Time Frame: From baseline until 30 days after last dose or initiation of new systemic anti-cancer therapy (up to 6 years overall) ]
- Atezolizumab Serum Concentration during Stage 1 [ Time Frame: Predose (0 hours [h]) on Day 1 of Cycles 1, 2, 3, 4, 8, 12, 16 (cycle = 21-28 days); postdose (30 min) (infusion = 30-60 min) on Day 1 of Cycle 1; at treatment discontinuation (up to 6 years); and 120 days after last dose (up to 6 years overall) ]
- Entinostat Serum and Plasma Concentration during Stage 1 [ Time Frame: Serum predose (0 h) and plasma postdose (2-4 h) on Day 1 of Cycle 1; plasma predose (0 h) on Day 1 of Cycle 2 (cycle = 21 days) ]
- Fulvestrant Plasma Concentration during Stage 1 [ Time Frame: Predose (0 h) on Day 1 of Cycles 2-3 (cycle = 28 days) ]
- Ipatasertib Plasma Concentration during Stage 1 [ Time Frame: Predose (0 h) and postdose (1, 2, 4, 6 h) on Day 15 of Cycle 1; postdose (1-3 h) on Day 15 of Cycle 3 ]
- Atezolizumab Serum Concentration during Stage 2 [ Time Frame: Predose (0 h) on Day 1 of Cycles 1, 2, 3, 4, 8, 12, 16 (cycle = 21-28 days); postdose (30 min) (infusion = 30-60 min) on Day 1 of Cycle 1; at treatment discontinuation (up to 6 years); and 120 days after last dose (up to 6 years overall) ]
- Bevacizumab Serum Concentration during Stage 2 [ Time Frame: Predose (0 h) and postdose (30 min) (infusion = 30-90 min) on Day 1 of Cycles 1, 3 (cycle = 21-28 days); at treatment discontinuation (up to 6 years); and 120 days after last dose (up to 6 years overall) ]
- Exemestane Plasma Concentration during Stage 2 [ Time Frame: Predose (0 h) on Day 1 of Cycle 2 (cycle = 21 days) ]
- Fulvestrant Plasma Concentration during Stage 2 [ Time Frame: Predose (0 h) on Day 1 of Cycles 2-3 (cycle = 28 days) ]
- Tamoxifen Plasma Concentration during Stage 2 [ Time Frame: Predose (0 h) on Day 1 of Cycle 2 (cycle = 21 days) ]
- Percentage of Participants with Anti-Drug Antibodies (ADAs) to Atezolizumab during Stage 1 [ Time Frame: Predose (0 h) on Day 1 of Cycles 1, 2, 3, 4, 8, 12, 16 (cycle = 28 days); at treatment discontinuation (up to 6 years); and 120 days after last dose (up to 6 years overall) ]
- Percentage of Participants with ADAs to Atezolizumab during Stage 2 [ Time Frame: Predose (0 h) on Day 1 of Cycles 1, 2, 3, 4, 8, 12, 16 (cycle = 21-28 days); at treatment discontinuation (up to 6 years); and 120 days after last dose (up to 6 years overall) ]
- Percentage of Participants with ADAs to Bevacizumab during Stage 2 [ Time Frame: Predose (0 h) on Day 1 of Cycles 1, 3 (cycle = 21-28 days); at treatment discontinuation (up to 6 years); and 120 days after last dose (up to 6 years overall) ]
- Abemaciclib Plasma Concentration during Stage 1 [ Time Frame: Predose (0 h), Postdose (30 minutes post infusion), and 4-8 hours after dose on Day 1 Cycle 1; Predose on Day 15 Cycle 1 and Day 1 of Cycles 2 and 3 ]

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Ages Eligible for Study: | 18 Years and older (Adult, Older Adult) |
Sexes Eligible for Study: | Female |
Accepts Healthy Volunteers: | No |
Inclusion Criteria for Both Stages:
- Measurable disease per RECIST v1.1
- Adequate hematologic and end organ function
- Disease progression during or after first- or second-line hormonal therapy with CDK4/6 inhibitor
Inclusion Criteria for Stage 1:
- Eastern Cooperative Oncology Group (ECOG) performance status 0-1
- Metastatic or inoperable, locally advanced, histologically or cytologically confirmed invasive HR-positive HER2-negative breast cancer
- Recommended for endocrine therapy, and cytotoxic chemotherapy not indicated at study entry
- Recurrence or progression following most recent systemic breast cancer therapy
- Disease progression during or after first- or second-line hormonal therapy for locally advanced or metastatic disease
- Postmenopausal according to protocol-defined criteria
- Life expectancy >3 months
- Available tumor specimen for determination of PD-L1 status
Inclusion Criteria for Stage 2:
- ECOG performance status of 0-2
- Ability to initiate treatment within 3 months after disease progression or unacceptable toxicity on a Stage 1 regimen
Exclusion Criteria for Both Stages:
- Significant or uncontrolled comorbid disease as specified in the protocol
- Uncontrolled tumor-related pain
- Autoimmune disease except for stable/controlled hypothyroidism, Type 1 diabetes mellitus, or certain dermatologic conditions
- Positive human immunodeficiency virus test
- Active hepatitis B or C
- Active tuberculosis
- Severe infection within 4 weeks and/or antibiotics within 2 weeks prior to study treatment
- Prior allogeneic stem cell or solid organ transplantation
- History of malignancy other than breast cancer within 2 years prior to screening except those with negligible risk of metastasis/death
- History of or known hypersensitivity to study drug or excipients
- For patients entering Stage 2, recovery from all immunotherapy-related adverse events to Grade 1 or better or to baseline at the time of consent
Exclusion Criteria for Stage 1:
- Prior fulvestrant or cytotoxic chemotherapy for metastatic breast cancer, or certain other agents as specified in the protocol
- Unresolved AEs from prior anti-cancer therapy
- Eligibility only for the control arm
- Prior treatment with inhibitors as specified in the protocol
Exclusion Criteria for Stage 2:
- Unacceptable toxicity with atezolizumab during Stage 1
- Uncontrolled cardiovascular disease or coagulation disorder, including use of anticoagulants as specified in the protocol
- Significant abdominal or intestinal manifestations within 6 months prior to treatment
- Grade 2 or higher proteinuria

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03280563

Study Director: | Clinical Trials | Hoffmann-La Roche |
Responsible Party: | Hoffmann-La Roche |
ClinicalTrials.gov Identifier: | NCT03280563 |
Other Study ID Numbers: |
CO39611 2017-000335-14 ( EudraCT Number ) |
First Posted: | September 12, 2017 Key Record Dates |
Last Update Posted: | March 22, 2023 |
Last Verified: | March 2023 |
Studies a U.S. FDA-regulated Drug Product: | Yes |
Studies a U.S. FDA-regulated Device Product: | No |
Breast Neoplasms Neoplasms by Site Neoplasms Breast Diseases Skin Diseases Tamoxifen Bevacizumab Atezolizumab Fulvestrant Exemestane Entinostat Ipatasertib Antibodies Antineoplastic Agents, Immunological Antineoplastic Agents |
Angiogenesis Inhibitors Angiogenesis Modulating Agents Growth Substances Physiological Effects of Drugs Growth Inhibitors Immunologic Factors Immune Checkpoint Inhibitors Molecular Mechanisms of Pharmacological Action Estrogen Antagonists Hormone Antagonists Hormones, Hormone Substitutes, and Hormone Antagonists Antineoplastic Agents, Hormonal Selective Estrogen Receptor Modulators Estrogen Receptor Modulators Bone Density Conservation Agents |