QLS1304 with endocrine therapy for advanced ER+/HER2- breast cancer

A Phase Ib/II Clinical Study to Evaluate Safety, Preliminary Efficacy and PK Characteristic of QLS1304 Combined With Endocrine Therapy in ER+/HER2- Breast Cancer Patients

This trial tests whether adding QLS1304 to standard endocrine therapy is safe and shows early signs of benefit for adults with advanced ER+/HER2- breast cancer who have progressed after prior hormone treatment.

Quick facts

• Phase: PHASE1; PHASE2
• Study type: Interventional
• Enrollment: 300 (estimated)
• Ages: 18 Years and up
• Sex: All
• Sponsor: Qilu Pharmaceutical Co., Ltd. (industry)
• Drugs / interventions: radiation
• Locations: 1 site (Shanghai)
• Trial ID: NCT07235176 on ClinicalTrials.gov

What this trial studies

This open-label phase Ib/II trial uses a two-stage design with a combination dose-escalation phase followed by a dose-expansion phase to define a recommended dose and further characterize safety and preliminary activity. Participants receive QLS1304 combined with endocrine agents such as fulvestrant or an aromatase inhibitor, and some cohorts may include QLC1401 with a CDK4/6 inhibitor. Key outcomes include safety, pharmacokinetics, and early efficacy signals measured by RECIST v1.1. The study is conducted at multiple centers with detailed monitoring during treatment and follow-up.

Who should consider this trial

Good fit: Adults (≥18) with histologically confirmed locally recurrent or metastatic ER+/HER2- breast cancer, ECOG 0–1, measurable disease per RECIST v1.1, adequate organ function, and prior failure of at least one endocrine therapy are the intended participants.

Not a fit: Patients with HER2-positive or triple-negative breast cancer, poor performance status, expected survival under 12 weeks, or contraindications to endocrine therapy or the study drugs are unlikely to benefit from this trial.

Why it matters

Potential benefit: If successful, the combination could provide a new treatment option that improves disease control for patients with endocrine-resistant ER+/HER2- breast cancer.

How similar studies have performed: Combining targeted agents with endocrine therapy and CDK4/6 inhibitors has improved outcomes in ER+/HER2- breast cancer, but QLS1304 and QLC1401 are novel agents with limited published clinical data.

Eligibility criteria

Inclusion Criteria:

1. Volunteer to participate in this study, sign an informed consent form and have good compliance;
2. Age ≥ 18 years old, Male or female
3. ECOG score: 0-1
4. Expected survival ≥ 12 weeks
5. Local recurrent or metastatic advanced ER+/HER2- breast cancer confirmed by histopathology or cytopathology;
6. Failed to at least one therapy line of endocrine therapy ;
7. Baseline presence of at least one measurable lesion according to the RECIST v1.1;
8. The functional level of important organs is basically normal, meeting the requirements of the scheme;
9. Female subjects with fertility and male subjects must agree to use highly effective contraception during the study treatment period and within 180 days after the last medication;
10. Female subjects with fertility must have a negative serum HCG test within 7 days before the first medication in the study, and must be in non lactation.
11. Volunteer to participate in this clinical trial, willing and able to follow the procedures related to clinical visits and research, understand the research procedures, and have signed informed consent.

Exclusion Criteria:

1. Subjects have received live or attenuated live vaccines within 4 weeks before the first use of the investigational drug.
2. Subjects have undergone major organ surgery within 4 weeks before the first use of the investigational drug.
3. Subjects require long-term or high-dose use of non-steroidal drugs.
4. Subjects have not recovered from adverse events (AEs) caused by previous anti-tumor treatment to ≤ grade 1.
5. Subjects have a known or suspected severe allergy to the investigational drug or any of its components.
6. Subjects have other active malignant tumors within 5 years before the first use of the investigational drug.
7. Subjects have brain metastases and/or carcinomatous meningitis or leptomeningeal disease.
8. Subjects have active tuberculosis, radiation pneumonitis, drug-induced pneumonitis, pulmonary fibrosis, or other diseases, symptoms, or signs of severe lung function impairment.
9. Subjects are unable to swallow tablets or had gastrointestinal abnormalities that the investigator assessed as potentially affecting drug absorption.
10. Subjects have a history of severe cardiovascular or cerebrovascular disease within 6 months before the first use of the investigational drug.
11. Subjects have a hypertension medial history that blood is not well controlled despite treatment with multiple antihypertension drugs.

Where this trial is running

Shanghai

• Fudan University Cancer Hospital — Shanghai, China (RECRUITING)

Conditions: Advanced ER+/HER2- Breast Cancer