A Phase I Study of RGT-419B in Patients With HR-Positive, HER2-Negative Advanced Breast Cancer or Other Solid Tumors

August 25, 2026 updated by: Regor Pharmaceuticals Inc.

A Phase I Study Evaluating Safety and Tolerability of RGT-419B Monotherapy in Chinese Patients With Hormone Receptor Positive, Human Epidermal Growth Factor Receptor 2 Negative Advanced/Metastatic Breast Cancer or Other Solid Tumors

This is a Phase 1 dose escalation and dose expansion phase I study to evaluate the safety, tolerability, pharmacokinetic profile and preliminary efficacy of RGT-419B as monotherapy in Chinese patients with HR+/HER2- advanced/metastatic breast cancer and other advanced solid tumors.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
40

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • China
    • Shanghai Municipality
      • Shanghai, Shanghai Municipality, China, 200032
        • Fudan University Shanghai Cancer Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Male or female ≥ 18 years of age
  • Eastern Cooperative Oncology Group (ECOG) performance status score of 0 or 1
  • Subjects with pathologically confirmed advanced solid tumors who have failed standard-of-care therapy, or have no standard-of-care therapy available, or are currently not eligible for standard-of-care therapy; Subjects with HR+/ HER2- advanced or metastatic breast cancer are preferred.
  • Estimated life expectancy of at least 12 weeks

Exclusion Criteria:

  • Presence of visceral metastases with severe organ dysfunction
  • Known active hepatitis B or C infection
  • Prior irradiation to >25% of the bone marrow and/or inadequate bone marrow function or evidence of clinicallysignificant end-organ damage
  • History of allergic reactions attributed to compounds of similar chemical or biologic composition to the drugs usedin the study

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: RGT-419B monotherapy
Dose escalation and dose expansion of RGT-419B monotherapy
Drug: RGT-419B
RGT-419B will be administered orally
Other Names:
  • Active drug

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Safety & Tolerability - Number of subjects with Dose-Limiting Toxicities (DLTs) at each cohort dose level
Time Frame: 4 weeks (1 cycle)
Number of subjects who have a confirmed DLT at each cohort dose level during the first 28-day cycle of RGT-419B treatment.
4 weeks (1 cycle)

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Safety & Tolerability - Incidence, Severity, and Causality of all Treatment Emergent Adverse Events (TEAEs)
Time Frame: through study completion, an average of 1 year
Incidence, severity, and causality of all TEAEs will be assessed for all patients participating from Day 1 dosing through end of study.
through study completion, an average of 1 year
Day 1 and steady-state pharmacokinetics(PK) assessment of RGT-419B and major metabolites - Cmax
Time Frame: 4 weeks (1 cycle)
4 weeks (1 cycle)
Day 1 and steady-state PK assessment of RGT-419B and major metabolites - Area Under Concentration-TimeCurve to Infinity (AUC0-inf)
Time Frame: 4 weeks (1 cycle)
4 weeks (1 cycle)
Day 1 and steady-state PK assessment of RGT-419B and major metabolites - Plasma Decay Half-Life (t1/2)
Time Frame: 4 weeks (1 cycle)
4 weeks (1 cycle)
Day 1 and steady-state PK assessment of RGT-419B and major metabolites - Time to Reach Maximum ObservedPlasma Concentration (Tmax)
Time Frame: 4 weeks (1 cycle)
4 weeks (1 cycle)
Day 1 and steady-state PK assessment of RGT-419B and major metabolites - Accumulation rate after multipledoses
Time Frame: 4 weeks (1 cycle)
4 weeks (1 cycle)
Day 1 and steady-state PK assessment of RGT-419B and major metabolites - Cumulative urinary excretion
Time Frame: 4 weeks (1 cycle)
4 weeks (1 cycle)
Tumor Response assessed by Investigator according to RECIST v1.1
Time Frame: through study completion, an average of 1 year
through study completion, an average of 1 year
QTc Interval - Changes in corrected QT interval
Time Frame: through study completion, an average of 1 year
Number of subjects with a clinically significant increase from baseline in corrected QT (QTc) interval onrepeated ECGs
through study completion, an average of 1 year

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Regor Pharmaceuticals Inc.

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Jian Zhang, MD, Fudan University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
April 17, 2023

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 30, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 30, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
March 1, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 1, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
March 7, 2024

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
August 27, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 25, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
August 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • RGT-419B-102

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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