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MCLA-128 With Trastuzumab/Chemotherapy in HER2+ and With Endocrine Therapy in ER+ and Low HER2 Breast Cancer.

Phase 2
Completed
Conditions
Breast Cancer Metastatic
Interventions
Registration Number
NCT03321981
Lead Sponsor
Merus N.V.
Brief Summary

A Phase 2, open-label, multicenter international study will be performed to evaluate the efficacy of MCLA-128-based combinations. Three combination treatments will be evaluated, two in Cohort 1 and one in Cohort 2.

MCLA-128 (zenocutuzumab) is given in combinations in two metastatic breast cancer (MBC) populations, Human Epidermal Growth Factor Receptor (HER) 2-positive/amplified (Cohort 1) and Estrogen Receptor-positive/low HER2 expression (Cohort2).

Two combinations treatments will be evaluated in Cohort 1, the doublet and triplet. Initially zenocutuzumab is given in combination with trastuzumab in the doublet. After the safety of the doublet has been assessed in 4-6 patients, MCLA-128 is given in combination with trastuzumab and vinorelbine in the triplet, in parallel to the efficacy expansion of the doublet.

The doublet and triplet combinations are both evaluated in two steps with an initial safety run-in followed by a cohort efficacy expansion. In total up to 40 patients evaluable for efficacy are included in both the doublet and triplet.

In Cohort 2 zenocutuzumab is administered in combination with the same previous endocrine therapy on which progressive disease is radiologically documented. A total of up to 40 patients evaluable for efficacy are included in the Cohort 2.

Detailed Description

Study Design Phase 2, open-label, multicenter international study to evaluate the efficacy of MCLA-128 (zenocutuzumab)-based combinations in 2 metastatic breast cancer populations, Human Epidermal Growth Factor Receptor (HER)2-positive/amplified (Cohort 1) and estrogen receptor-positive/low-HER2 expression (Cohort 2). Three combination treatments were evaluated, 2 in Cohort 1 and 1 in Cohort 2.

Cohort 1: To be eligible, patients had to have HER2-positive/amplified metastatic breast cancer, with confirmed HER2 overexpression by Immunohistochemistry (IHC) with a score of 3+ or of 2+ combined with positive Fluorescence in Situ Hybridization (FISH), have received up to 5 lines of HER2-directed therapy in the metastatic setting, and have progressed on the most recent line per Response Evaluation Criteria In Solid Tumors Guidelines (RECIST) v1.1, and have been previously treated with trastuzumab, pertuzumab and an HER2 Antibody-Drug Conjugates (ADC) in any sequence and any setting.

Initially zenocutuzumab was administered with trastuzumab (doublet combination). Safety was reviewed by an Independent Data Monitoring Committee (IDMC). If the safety of the doublet was approved, the triplet combination of zenocutuzumab plus trastuzumab and vinorelbine was to be evaluated in parallel with the doublet combination.

The doublet and triplet Cohort 1 combinations were each evaluated in 2 steps with an initial safety run-in period in 4 to 6 patients who were reviewed by the IDMC before deciding to expand the cohort. The triplet combination go/no-go decision was made by the IDMC after evaluation of the doublet safety run-in patients (based on Adverse Avents \[AEs\], Serious Adverse Events \[SAEs\], relationship to study drug, and other clinically relevant parameters \[eg, laboratory parameters\], available pharmacokinetics, immunogenicity, and cytokine data). If the triplet combination was considered safe, the expansion of the doublet and triplet combinations was performed in parallel. Patients were included in the triplet or doublet in a 3:1 ratio, taking into account previous exposure to vinorelbine.

After the safety run-in, if Cohort 1 doublet and Cohort 1 triplet combination therapies were considered tolerable by the IDMC, they were each to be expanded to a total of up to 40 patients evaluable for efficacy. If the doublet combination regimen was not well tolerated, Cohort 1 was to be closed. If the triplet combination was not well tolerated but the doublet was acceptable, the doublet expansion was to be continued.

Cohort 2: To be eligible, patients had to have estrogen receptor-positive and low-HER2 expression metastatic breast cancer (IHC 1+, or IHC 2+ combined with negative FISH), and radiologic or photographic evidence of disease progression on the last line of prior endocrine therapy (administered for ≥12 weeks) that included an aromatase inhibitor (AI) or fulvestrant. Patients who had received up to 3 prior endocrine therapies in the metastatic setting and had progressed on a Cyclin-Dependent Kinase (CDK) inhibitor (in any line) were eligible.

Zenocutuzumab was administered in combination with the same previous endocrine therapy on which progressive disease was radiologically/photographically documented. Up to 40 patients evaluable for efficacy were included.

Recruitment & Eligibility

Status
COMPLETED
Sex
Female
Target Recruitment
105
Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Cohort 1 tripletZenocutuzumabzenocutuzumab + trastuzumab + vinorelbine
Cohort 1 tripletVinorelbinezenocutuzumab + trastuzumab + vinorelbine
Cohort 1 doubletZenocutuzumabzenocutuzumab + trastuzumab
Cohort 1 doubletTrastuzumabzenocutuzumab + trastuzumab
Cohort 2Zenocutuzumabzenocutuzumab + endocrine therapy
Cohort 2Endocrine therapyzenocutuzumab + endocrine therapy
Cohort 1 tripletTrastuzumabzenocutuzumab + trastuzumab + vinorelbine
Primary Outcome Measures
NameTimeMethod
Clinical Benefit Rate at 24 Weeks24 weeks

Clinical benefit rate (CBR) at 24 weeks per investigator assessment. CBR is the proportion of patients with confirmed Complete Response (CR) or Partial Response (PR), or Stable Disease (SD) lasting 24 weeks.

Secondary Outcome Measures
NameTimeMethod
Progression Free Survival (PFS) Per Central ReviewBaseline, every 6 weeks until end of treatment, every 3 months thereafter up to 1 year after treatment (if not progressed at end of treatment)

For assessment per RECIST v1.1, PFS is the time from the date of treatment start to the date of event defined as the first documented progression or death due to any cause.

Overall Response Rate (ORR) Per Investigator AssessmentBaseline, every 6 weeks until end of treatment, every 3 months thereafter up to 1 year after treatment (if not progressed at end of treatment)

The proportion of patients with overall response of Complete Response or Partial Response based upon RECIST 1.1 (confirmed response).

Overall Response Rate (ORR) Per Central ReviewBaseline, every 6 weeks until end of treatment, every 3 months thereafter up to 1 year after treatment (if not progressed at end of treatment)

The proportion of patients with overall response of Complete Response or Partial Response based upon RECIST 1.1 (confirmed response).

Duration of Response (DoR) Per Investigator AssessmentBaseline, every 6 weeks until end of treatment, every 3 months thereafter up to 1 year after treatment (if not progressed at end of treatment)

DoR applies only to patients with a Best Overall Response (BOR) of confirmed CR or PR (RECIST v1.1). For RECIST v1.1, DoR is defined as the time from the date of the first documented response (CR or PR) to the date of first documented progression, or death due to any cause.

Duration of Response (DoR) Per Central ReviewBaseline, every 6 weeks until end of treatment, every 3 months thereafter up to 1 year after treatment (if not progressed at end of treatment)

DoR applies only to patients with a BOR of confirmed CR or PR (RECIST v1.1). For RECIST v1.1, DOR is defined as the time from the date of the first documented response (CR or PR) to the date of first documented progression, or death due to any cause.

Overall Survival (OS)Baseline, every 6 weeks until end of treatment, every 3 months thereafter up to 1 year after treatment (if not progressed at end of treatment)

The time from treatment start until death due to any cause.

Number of Patients With Adverse Events (AE's) Leading to Discontinuation of Study DrugDuring study treatment and up to 30 days after last administration of study drug (median duration of zenocutuzumab exposure was 6.0 weeks for Cohort 1 doublet, 19.3 weeks for Cohort 1 triplet and 11.8 weeks for Cohort 2).

Evaluation of number of participants with Adverse Events leading to leading to discontinuation of study drug

Number of Patients With AE's of Special Interest (AESI)During study treatment and up to 30 days after last administration of study drug (median duration of zenocutuzumab exposure was 6.0 weeks for Cohort 1 doublet, 19.3 weeks for Cohort 1 triplet and 11.8 weeks for Cohort 2).

AESIs for MCLA-128 combinations include:

Infusion-related reactions (for any antibodies, known AESI for MCLA-128) Cardiotoxicity (anti-Human Epidermal Growth Factor Receptor (HER)2 therapy) Diarrhea (anti-HER2 therapy) Myelosuppression (vinorelbine)

Anti-drug Antibodies Serum TitersPre-dose for each of cycles 1, 3 and 5, and every 4 cycles thereafter, and at the End of Treatment visit.

Number of patients with anti-drug antibodies at baseline and on treatment

Progression Free Survival (PFS) Per Investigator AssessmentBaseline, every 6 weeks until end of treatment, every 3 months thereafter up to 1 year after treatment (if not progressed at end of treatment)

For assessment per Response Evaluation Criteria In Solid Tumors Guidelines (RECIST) v1.1, PFS is the time from the date of treatment start to the date of event defined as the first documented progression or death due to any cause.

Trial Locations

Locations (25)

Champalimaud Clinical Centre

🇵🇹

Lisbon, Portugal

Hopistal San Antonio

🇵🇹

Porto, Portugal

Instituto Valenciano de Oncologia

🇪🇸

Valencia, Spain

Instituto Português Oncologia

🇵🇹

Porto, Portugal

Hospital Clinic. C/Villaroel

🇪🇸

Barcelona, Spain

Institute Gustave Roussy

🇫🇷

Villejuif, France

Centre Léon Bérard

🇫🇷

Lyon, France

UZ Leuven

🇧🇪

Leuven, Belgium

Centre Claudius Régaud

🇫🇷

Toulouse, France

Ramon Y Cajal Universitary Hospital

🇪🇸

Madrid, Spain

Hospital Universitario 12de Octubre

🇪🇸

Madrid, Spain

Centre Jean Perrin

🇫🇷

Clermont-Ferrand, France

Centre Georges-Francois Leclerc

🇫🇷

Dijon, France

Centre René Huguenin

🇫🇷

Saint-Cloud, France

Cedars-Sinai Medical Center

🇺🇸

Los Angeles, California, United States

Sarah Cannon Research Institute

🇺🇸

Nashville, Tennessee, United States

HCA Midwest Health

🇺🇸

Kansas City, Kansas, United States

Grand Hôpital de Charleroi (GHdC)

🇧🇪

Charleroi, Belgium

Institut Jules Bordet

🇧🇪

Brussel, Belgium

Hôpital Jean Minjoz

🇫🇷

Besançon, France

Institut Paoli Calmette

🇫🇷

Marseille, France

Netherlands Cancer Institute NKI

🇳🇱

Amsterdam, Noord Holland, Netherlands

Centre Paul Strauss

🇫🇷

Strasbourg, France

Vall D'Hebron Institute of Oncology (VHIO)

🇪🇸

Barcelona, Spain

Sarah Cannon Research Institute UK

🇬🇧

London, United Kingdom

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