Maintenance Therapy in HER2-Positive Unresectable Locally Recurrent or Metastatic Breast Cancer: A Phase II Study

Official title

A Multicenter, Open-Label, Phase II Trial of Exploring the Maintenance of Trastuzumab Plus Pyrotinib or Trastuzumab Plus Dalpiciclib and Endocrine Therapy Based on HR Status Following Trastuzumab Rezetecan as Induction Treatment for HER2 Positive Unresectable Locally Recurrent or Metastatic Breast Cancer

Overview

This is a phase II trial exploring the maintenance therapy with trastuzumab combined with pyrotinib or dalpiciclib and endocrine therapy in HER2-positive advanced breast cancer based on different hormone receptor (HR) statuses following trastuzumab rezetecan (T-DXh, SHR-A1811) as induction treatment for HER2-positive unresectable locally recurrent or metastatic breast cancer (MBC) patients.

Interventions

• Drug Trastuzumab rezetecan
  Trastuzumab rezetecan is a lyophilized powder for injection intravenously. Administered according to label.
• Drug Pyrotinib
  320 mg/d, q.d., p.o. A course of treatment need 21 days.
• Drug Dalpiciclib
  125 mg/d, q.d., p.o. day 1-21, every 28 days.
• Drug Trastuzumab
  Administered according to label.
• Drug ET: Letrozole/ Anastrozole/ Exemestane/ Fulvestrant/ Leuprorelin/ Goserelin.
  Administered according to label.

Primary outcome measures

• PFS [Time frame: From the date of treatment initiation until to the first occurrence of disease progression as determined locally by the investigator assessment using RECIST v.1.1 or death from any cause, whichever occurs first，assessed up to 60 months]

Secondary outcome measures (3)

• OS [Time frame: From the date of treatment initiation to the death from any cause, assessed up to 84 months]
• Objective response rate (ORR) [Time frame: At least 4 weeks after first documented response]
• Safety and tolerability [Time frame: From the date of treatment initiation until to the discontinuation of treatment，assessed up to 60 months]

Eligibility criteria

Inclusion criteria

To be eligible to participate in this trial, an individual must meet ALL the following criteria:

• Patient must be capable to understand the purpose of the study and have signed written informed consent form (ICF) prior to beginning specific protocol procedures.
• Female patients ≥ 18 years of age at the time of signing ICF.
• Breast Cancer Requirements:

• Histologically or cytologically confirmed HER2-positive(IHC 3+ or ISH+) unresectable locally advanced or metastatic breast cancer (Note: Patients eligible for curative-intent treatment are excluded).
• Documented hormone receptor (HR) status.
• No prior systemic anti-tumor therapy for recurrent/metastatic disease (≤1 line of endocrine therapy is permitted\*).
• For patients who received (neo)adjuvant therapy: >12 months between the end of systemic treatment (excluding endocrine therapy) and recurrence/metastasis.
• Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 or 1.
• Adequate Organ Function.
• Pregnancy and Contraception: Women of childbearing potential (WOCBP) must agree to use highly effective contraception from screening until7 months after the last dose of study treatment and must refrain from breastfeeding.

Exclusion criteria

An individual who meets ANY of the following criteria will be excluded from participation in this trial:

• Known active CNS metastases not treated with surgery or radiotherapy, except for those who have achieved stable disease for ≥1 month after treatment and have discontinued corticosteroids for >2 weeks.
• Received major cancer-related surgery, radiotherapy, chemotherapy, immunotherapy, molecular targeted therapy, biologic therapy, or investigational drug therapy within 4 weeks prior to the first dose of study treatment.
• Previous treatment with antibody-drug conjugates containing exatecan derivative topoisomerase I inhibitors.
• Presence of clinically significant cardiovascular conditions, including:

• Severe/unstable angina
• Symptomatic congestive heart failure (NYHA class ≥II)
• Clinically significant supraventricular or ventricular arrhythmias requiring treatment or intervention
• Myocardial infarction within 6 months before the first dose
• Has a history of non-infectious interstitial lung disease (ILD)/pneumonitis that required steroids, has current ILD/pneumonitis, or has suspected ILD/pneumonitis that cannot be ruled out by imaging at screening.
• Known substance abuse or any other concurrent severe and/or uncontrolled medical condition that would, in the investigator's judgment, contraindicate patient participation.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

N/A

Model

Single group

Masking

Open label

Primary purpose

Treatment

Study locations

China · 1 center

• Fudan University — Shanghai

Identifiers

NCT: NCT07179939 · MA-BC-II-111

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗