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.

NCT07207070 | Recruiting Phase 3

• 1 other identifier: JS105-004-III-BC
• Study Type: interventional
• Target: 312
• Locations: 1 country
• Sites: 2

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.

Conditions

Breast Cancer

Outcome Measures

Primary Outcomes (1)

• Blind Independent Central Review (BICR) assessed PFS based on RECIST v1.1 (BICR-PFS)

  PFS is defined as the time from randomization to the first occurrence of disease progression or death from any cause (whichever occurs first).

  Up to 3.5 years

Secondary Outcomes (8)

• Overall Survival (OS)

  Up to 5 years

• Investigator-assessed Progression-Free Survival (PFS)

  Up to 3.5 years

• 1-year and 2-year Progression-Free Survival (PFS) rate

  Up to 3.5 years

• Objective Response Rate (ORR)

  Up to 5 years

• Duration of Objective Response (DOR)

  Up to 5 years

Study Arms (2)

JS105+Dalpiciclib+Fulvestrant

EXPERIMENTAL

Patients will receive JS105, Dalpiciclib and Fulvestrant.

Drug: JS105; Drug: Dalpiciclib; Drug: Fulvestrant 50 Mg/mL Intramuscular Solution

Dalpiciclib+Fulvestrant

ACTIVE COMPARATOR

Patients will receive Dalpiciclib and Fulvestrant.

Drug: Dalpiciclib; Drug: Fulvestrant 50 Mg/mL Intramuscular Solution

Interventions

Fulvestrant 50 Mg/mL Intramuscular Solution DRUG

Patients will receive intramuscular Fulvestrant on day 1 and day 15 of the first cycle and then on day 1 of each subsequent 4-week cycle.

Dalpiciclib+Fulvestrant; JS105+Dalpiciclib+Fulvestrant

JS105 DRUG

Patients will receive oral JS105 on Days 1-28 of each 4-week cycle.

JS105+Dalpiciclib+Fulvestrant

Dalpiciclib DRUG

Patients will receive oral Dalpiciclib for 3 weeks, followed by 1 week off in each 4-week cycle；

Dalpiciclib+Fulvestrant; JS105+Dalpiciclib+Fulvestrant

Eligibility Criteria

• Age: 18 Years - 75 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

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

You may not qualify if:

• Previously treated with fulvestrant or PI3K/AKT/mTOR inhibitors;
• Presence of untreated or active central nervous system (CNS) metastases;
• Presence of significant clinical symptoms or uncontrolled pleural effusion, ascites, or pericardial effusion that require repeated drainage (once a month or more frequently);
• 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;
• Have received other anti-tumor treatment within 2-4 weeks before the first dose;
• Toxicities from prior anti-tumor therapy that have not recovered to ≤ Grade 1;
• 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;
• 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;
• Active hepatitis B or C;
• Known hypersensitivity to any of the study drugs or their excipients;
• Pregnant or breastfeeding females;
• 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;

Sponsors & Collaborators

• Risen (Suzhou) Pharma Tech Co., Ltd.: lead

Study Sites (2)

Chinese Acadamy of Medical Sciences and Peking Union Medical College

Beijing, Beijing Municipality, 100021, China

RECRUITING

Henan Provincial Cancer Hospital

Zhengzhou, Henan, 450003, China

RECRUITING

MeSH Terms

Conditions

Breast Neoplasms

Interventions

dalpiciclib; Fulvestrant

Condition Hierarchy (Ancestors)

Neoplasms by Site; Neoplasms; Breast Diseases; Skin Diseases; Skin and Connective Tissue Diseases

Intervention Hierarchy (Ancestors)

Estradiol; Estrenes; Estranes; Steroids; Fused-Ring Compounds; Polycyclic Compounds; Estradiol Congeners; Gonadal Steroid Hormones; Gonadal Hormones; Hormones; Hormones, Hormone Substitutes, and Hormone Antagonists

Study Officials

• Xianming Luo, Doctor

  Medical Director

  STUDY DIRECTOR

Central Study Contacts

Qianna Zhan, Master

CONTACT

13526615319; zhan@junshipharma.com

Huiyu Lan, Master

CONTACT

15000239047; huiyu_lan@junshipharma.com

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Model Details: Experimental group：JS105:Dose according to the protocal, orally, once daily (QD), administered continuously. Dalpiciclib :Dose according to the protocal, orally, QD, taken for 3 weeks, followedby 1 week off in each 4-week cycle； Fulvestrant Dose according to the protocal, administered intramuscularly on day 1 and day 15 of the first cycle and then on day 1 of each subsequent 4-week cycle. Control group：Dalpiciclib : Dose according to the protocal, orally, QD, taken for 3 weeks, followed by 1 week off in each 4-week cycle；Fulvestrant: Dose according to the protocal, administered intramuscularly on day 1 and day 15 of the first cycle and then on day 1 of each subsequent 4-week cycle.

Study Record Dates

• First Submitted: September 26, 2025
• First Posted: October 3, 2025
• Study Start: November 12, 2025
• Primary Completion (Estimated): May 31, 2029
• Study Completion (Estimated): May 31, 2030
• Last Updated: December 30, 2025

Record last verified: 2025-12

Locations

CN (2)