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Phase 2 Study of BB-1701 in HER2 positive or HER2-low metastatic breast cancer

An Open-label, Multicenter, Phase 2 Dose Optimization and Expansion Study to Evaluate the Safety and Efficacy of BB-1701, an anti-human epidermal growth factor receptor 2 (anti-HER2) antibody-drug conjugate (ADC), in Previously Treated Subjects with HER2-positive or HER2-low Unresectable or Metastatic Breast Cancer

Status
Active, not recruiting
Phases
Phase 2
Study type
Interventional
Source
JPRN
Registry ID
JPRN-jRCT2031230750
Enrollment
135
Registered
2024-03-28
Start date
2025-04-11
Completion date
Unknown
Last updated
2026-06-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

HER2-positive or HER2-low unresectable or metastatic breast cancer

Interventions

Generic Name:NA Study Treatment in dose optimization part:BB-1701 (1.6mg/kg Q3W, 0.8mg/kg day1,8 Q3W, 1.2mg/kg Q3W) will be administered intravenously. Study Treatment in dose expansion part:One of th

Sponsors

Suzuki Takuya
Lead Sponsor

Eligibility

Sex/Gender
All

Inclusion criteria

Inclusion criteria: (1) Male or female, aged >=18 years at the time of informed consent. (2) Metastatic or unresectable BC that is histologically confirmed to be either HER2-positive (defined as an immunohistochemistry [IHC] status of 3+, or a positive in situ hybridization [ISH] test [fluorescence, chromogenic, or silver-enhanced ISH] if IHC status is 2+) or HER2-low (defined as an IHC status of 1+, or 2+ and negative ISH) per the American Society of Clinical Oncology/College of American Pathology guidelines as documented prior to trastuzumab deruxtecan (T-DXd) treatment. (3) Must have previously received T-DXd. (4) Sufficient tumor tissue is required for HER2 status testing at a central laboratory. (5) Measurable disease per RECIST 1.1 as assessed by the investigator. Participants with bone only disease may be eligible if there is a measurable soft tissue component associated with the bone lesion. (6) Must have previously received at least 1 but no more than 3 prior chemotherapy-based regimes in the unresectable or metastatic setting. If recurrence occurred within 6 months of (neo)adjuvant chemotherapy, this would count as 1 line of chemotherapy. Antibody drug conjugate is also counted as 1 line of chemotherapy. (7) If HR-positive HER2-low BC, must have previously received endocrine therapy unless clinically not indicated and is not expected to benefit from further endocrine therapy. (8) ECOG PS 0 or 1. (9) Life expectancy of at least 3 months. (10) Adequate organ function and laboratory parameters.

Exclusion criteria

Exclusion criteria: (1) Presence of brain or subdural metastases, unless participants has completed local therapy and has discontinued the use of corticosteroids for this indication for at least 2 weeks prior to starting treatment in this study. (2) Diagnosed with meningeal carcinomatosis. (3) Received anticancer therapy (chemotherapy or other systemic anticancer therapies, immunotherapy, radiation therapy, etc) or an investigational drug or device within the past 28 days or 5 half-lives, whichever is shorter. (4) Prior treatment with eribulin. (5) History of Grade >=3 hypersensitivity to monoclonal antibodies or contraindication to the receipt of corticosteroids or any of the excipients (investigators should refer to the prescribing information for the selected corticosteroid). (6) Residual toxic effects of prior therapies or surgical procedures that is Grade >=2 (except alopecia or anemia). (7) Grade >=2 peripheral neuropathy or history of Grade >=3 peripheral neuropathy or discontinued any prior treatment due to peripheral neuropathy. (8) Active pneumonitis/interstitial lung disease (ILD) or any clinically significant lung disease (example, chronic obstructive pulmonary disease), history of Grade >=2 pneumonitis/ILD, or received radiotherapy to lung fields within 12 months of Cycle 1 Day 1 of study treatment. (9) Congestive heart failure greater than New York Heart Association Class II or left ventricular ejection fraction (LVEF) ) 470 millisecond (ms) (for both males and females) based on screening triplicate 12-lead ECG. (11) Concomitant active infection requiring systemic treatment, except: a) If known to be human immunodeficiency virus (HIV)-positive, must be on anti-HIV therapy for at least 4 weeks and have a clusters of differentiation 4+ T-cell (CD4+) count >=350 cells per microliter (cells/mcL) and an HIV viral load less than 400 copies per milliliter (copies/mL). b) If meets the criteria for anti-hepatitis B virus (HBV) therapy, must agree to take anti-HBV therapy, if known to be HBV-positive as defined by positive hepatitis B surface antigen or hepatitis B core antibody. HBV viral load must be undetectable. c) If known to be hepatitis C virus (HCV)-positive must have completed curative therapy for HCV. HCV viral load must be undetectable. (12) Known history of active bacillus tuberculosis (TB). (13) Any medical or other condition which, in the opinion of the investigator would preclude the participant's participation in the clinical study.

Design outcomes

Primary

MeasureTime frame
The primary purpose of the Dose Optimization par is to assess the safety and tolerability of BB-1701 and to determine the recommended dose (RD) of BB-1701 for Dose Expansion. The primary purpose of Dose Expansion is to assess the efficacy of BB-1701 at RD in the selected population(s) of breast cancer.

Secondary

MeasureTime frame
Secondary endpoints in dose optimization part is to evaluate further efficacy of BB-1701 in each dose cohort and pharmacokinetics (PK) of BB-1701, as well as relationship between BB-1701 exposure and specific efficacy and safety evaluation indicators. The secondary endpoint in dose expansion part is to evaluate effectiveness of BB-1701 in RD in specific BC populations, as well as further efficacy, safety and tolerability of BB-1701 in RD in expansion part.

Countries

Canada, France, Japan, Spain, US

Contacts

Public ContactInquiry service

Eisai Co., Ltd.

eisai-chiken_hotline@hhc.eisai.co.jp+81-3-3817-5252

Outcome results

None listed

Source: JPRN (via WHO ICTRP) · Data processed: Jul 3, 2026