A Randomised, Open-label, Multicentre Phase III Clinical Study to Evaluate the Efficacy and Safety of JS105 Combined With Dalpiciclib and Fulvestrant Compared With Dalpiciclib and Fulvestrant in Patients With PIK3CA-mutated, HR-positive, HER2-negative Recurrent or Metastatic Breast Cancer.

Not Applicable

Not yet recruiting

• Conditions: Breast Cancer
• Interventions: Drug: JS105; Drug: Dalpiciclib; Drug: Fulvestrant 50 Mg/mL Intramuscular Solution

• Registration Number: NCT07207070
• Lead Sponsor: Risen (Suzhou) Pharma Tech Co., Ltd.

Brief Summary

This study is a randomised, open-label, multicentre phase III clinical study evaluating the efficacy and safety of JS105 combined with Dalpiciclib and Fulvestrant compared with Dalpiciclib and Fulvestrant in patients with PIK3CA-mutated, HR-positive, HER2-negative recurrent or metastatic breast cancer.

Detailed Description

Not available

Study Timeline

• Status Verified: 2025-09
• Study First Submitted: 2025-09-26
• Study First Submitted QC: 2025-09-26
• Last Update Submitted: 2025-09-26
• Study First Posted: 2025-10-03
• Last Update Posted: 2025-10-03
• Study Start: 2025-11-28
• Primary Completion: 2029-05-31
• Study Completion: 2030-05-31

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: All
• Target Recruitment: 312

Inclusion Criteria

1. At the time of signing the consent form, age must be between 18 and 75 years old, males and females;
2. Patients with unresectable PIK3CA-mutated HR-positive HER2-negative recurrent or metastatic breast cancer;
3. Consent to provide tumour tissue or blood samples to determine the PIK3CA mutation status;
4. ECOG 0 or 1;
5. At least one measurable lesion as per RECIST v1.1, or only bone metastases;
6. Expected survival≥12 weeks;
7. Good organ function;
8. Patients voluntarily join the study and sign the informed consent;

Exclusion Criteria

1. Previously treated with fulvestrant or PI3K/AKT/mTOR inhibitors;
2. Presence of untreated or active central nervous system (CNS) metastases;
3. Presence of significant clinical symptoms or uncontrolled pleural effusion, ascites, or pericardial effusion that require repeated drainage (once a month or more frequently);
4. Untreated spinal cord compression, or previously treated spinal cord compression without clinical evidence of disease stability for at least 4 weeks prior to the first study treatment;
5. Have received other anti-tumor treatment within 2-4 weeks before the first dose;
6. Toxicities from prior anti-tumor therapy that have not recovered to ≤ Grade 1;
7. Coexisting uncontrolled accompanying diseases, including but not limited to: history of type I diabetes or uncontrolled type II diabetes, presence of active infection, severe cardiovascular or cerebrovascular diseases, etc;
8. Having another malignant tumour within the last 5 years prior to the first study treatment, except for malignancies that are expected to be cured after treatment;
9. Active hepatitis B or C;
10. Known hypersensitivity to any of the study drugs or their excipients;
11. Pregnant or breastfeeding females;
12. Presence of other serious physical or mental illnesses or laboratory abnormalities that may increase the risk of participation in the study, affect treatment compliance, or interfere with study results, as judged by the investigator;

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
JS105+Dalpiciclib+Fulvestrant	JS105	Patients will receive JS105, Dalpiciclib and Fulvestrant.
JS105+Dalpiciclib+Fulvestrant	Dalpiciclib	Patients will receive JS105, Dalpiciclib and Fulvestrant.
JS105+Dalpiciclib+Fulvestrant	Fulvestrant 50 Mg/mL Intramuscular Solution	Patients will receive JS105, Dalpiciclib and Fulvestrant.
Dalpiciclib+Fulvestrant	Dalpiciclib	Patients will receive Dalpiciclib and Fulvestrant.
Dalpiciclib+Fulvestrant	Fulvestrant 50 Mg/mL Intramuscular Solution	Patients will receive Dalpiciclib and Fulvestrant.

Primary Outcome Measures

Name	Time	Method
Blind Independent Central Review (BICR) assessed PFS based on RECIST v1.1 (BICR-PFS)	Up to 3.5 years	PFS is defined as the time from randomization to the first occurrence of disease progression or death from any cause (whichever occurs first).

Secondary Outcome Measures

Name	Time	Method
Overall Survival (OS)	Up to 5 years	OS is defined as the time from randomization to death from any cause.
Investigator-assessed Progression-Free Survival (PFS)	Up to 3.5 years	PFS is defined as the time from randomization to the first occurrence of disease progression or death from any cause (whichever occurs first).
1-year and 2-year Progression-Free Survival (PFS) rate	Up to 3.5 years	1-year and 2-year Progression-Free Survival (PFS) rate
Objective Response Rate (ORR)	Up to 5 years	Objective Response Rate (ORR) as Assessed by Investigator or BICR according to RECIST v1.1
Duration of Objective Response (DOR)	Up to 5 years	Duration of Objective Response (DOR) as Assessed by Investigator or BICR according to RECIST v1.1
Disease Control Rate(DCR)	Up to 5 years	Disease Control Rate(DCR) as Assessed by Investigator or BICR according to RECIST v1.1
Adverse Event	Up to 5 years	Collect Serious Adverse Events (SAEs) and Adverse Events (AEs) from the time of signing the Informed Consent Form (ICF) until the safety follow-up visit.Evaluate the safety of the investigational drug.
Plasma Concentration of JS105	Up to 3.5 years	Collect JS105 PK sample to evaluate the blood drug concentration after the administration of JS105.

Trial Locations

Locations (2)

Chinese Acadamy of Medical Sciences and Peking Union Medical College; 🇨🇳 Beijing, Beijing Municipality, China

Henan Provincial Cancer Hospital; 🇨🇳 Zhengzhou, Henan, China