JSKN016 in Combination With D-0502 for Locally Advanced or Metastatic HR-Positive, HER2-Negative Breast Cancer

NCT07336771 | Not Yet Recruiting Phase 1

• 1 other identifier: JSKN016-204
• Study Type: interventional
• Target: 60
• Locations: 1 country
• Sites: 1

Brief Summary

This is a multicenter, open-label, Phase Ib/II randomized study designed to evaluate the safety, tolerability, dose-limiting toxicities (DLTs), and preliminary antitumor activity of JSKN016 in combination with the oral selective estrogen receptor degrader (SERD) D-0502 in patients with locally advanced or metastatic hormone receptor-positive (HR+), HER2-negative breast cancer who have previously progressed on CDK4/6 inhibitor-based endocrine therapy. Approximately 60 patients will be randomized in a 1:1 ratio to receive JSKN016 administered intravenously every 2 weeks (Q2W) or every 3 weeks (Q3W), in combination with daily oral D-0502. Each dosing cohort will include a safety lead-in phase to assess DLTs prior to cohort expansion. Tumor response will be assessed according to RECIST v1.1.

Conditions

Locally Advanced Breast Cancer (LABC); Metastatic Breast Cancer

Outcome Measures

Primary Outcomes (3)

• Incidence of dose-limiting toxicities (DLTs)

  From first dose through the end of Cycle 1 (approximately 21 days)

• Objective Response Rate (ORR)

  From first dose through treatment discontinuation, assessed up to 12 months

• Safety and tolerability (TEAEs, TRAEs, SAEs)

  From first dose until 30 days after the last dose of study treatment.

Secondary Outcomes (5)

• Disease Control Rate (DCR)

  From first dose through 24 weeks

• Duration of Response (DoR)

  From first documented objective response (CR or PR) until disease progression or death, whichever occurs first, assessed up to 24 months

• Clinical Benefit Rate (CBR)

  From first dose through 24 weeks

• Progression-Free Survival (PFS)

  From first dose until the first documented disease progression or death from any cause, whichever occurs first, assessed up to 24 months

• Overall Survival (OS)

  From first dose until death from any cause, assessed up to 36 months

Study Arms (2)

JSKN016 Q2W + D-0502

EXPERIMENTAL

Drug: JSKN016 Q2W; Drug: D-0502

JSKN016 Q3W + D-0502

EXPERIMENTAL

Drug: JSKN016 Q3W; Drug: D-0502

Interventions

JSKN016 Q3W DRUG

4 mg/kg, intravenous infusion, every 3 weeks

JSKN016 Q3W + D-0502

D-0502 DRUG

200 mg, oral, once daily

JSKN016 Q2W + D-0502; JSKN016 Q3W + D-0502

JSKN016 Q2W DRUG

4 mg/kg, intravenous infusion, every 2 weeks

JSKN016 Q2W + D-0502

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age ≥18 years
• Histologically or cytologically confirmed locally advanced or metastatic HR-positive, HER2-negative breast cancer
• HR-positive defined as ER and/or PR ≥1% by IHC
• HER2-negative per ASCO/CAP guidelines
• At least one measurable extracranial lesion per RECIST v1.1
• ECOG performance status 0-1
• Prior progression on CDK4/6 inhibitor plus endocrine therapy
• Adequate organ and cardiac function
• Postmenopausal women, or premenopausal women receiving ovarian function suppression

You may not qualify if:

• Active or untreated CNS metastases
• Prior treatment with ADCs containing topoisomerase I inhibitor payloads
• Active interstitial lung disease or pneumonitis
• Uncontrolled cardiovascular disease or active infection
• Prior malignancy within 5 years (with specific exceptions)
• Pregnancy or breastfeeding

Sponsors & Collaborators

• Jiangsu Alphamab Biopharmaceuticals Co., Ltd: lead

Study Sites (1)

Fudan University Shanghai Cancer center

Shanghai, China

Location

MeSH Terms

Conditions

Breast Neoplasms

Condition Hierarchy (Ancestors)

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

Central Study Contacts

Xiaowen Tang

CONTACT

+86-512-62850800; xiaowentang@alphamabonc.com

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: December 23, 2025
• First Posted: January 13, 2026
• Study Start: January 1, 2026
• Primary Completion (Estimated): December 1, 2027
• Study Completion (Estimated): June 1, 2028
• Last Updated: January 13, 2026

Record last verified: 2026-01

Data Sharing

• IPD Sharing: Will not share

Locations

CN (1)