What is the mechanism of action of this treatment?

The most common treatments for hormone receptor-positive breast cancer include endocrine therapies and targeted therapies. Endocrine therapies, such as aromatase inhibitors and selective estrogen receptor modulators (SERMs), work by reducing estrogen levels or blocking estrogen receptors, thereby inhibiting the growth of hormone-dependent cancer cells. Targeted therapies, like CDK4/6 inhibitors, work by interfering with specific molecules involved in cancer cell proliferation. These mechanisms are crucial for breast cancer patients as they provide more personalized and effective treatment options, potentially leading to better outcomes and fewer side effects compared to traditional chemotherapy.

What side effects are associated with this type of intervention?

Common treatments for hormone receptor-positive breast cancer include tamoxifen, aromatase inhibitors (such as anastrozole), and other endocrine therapies. Tamoxifen can cause side effects like hot flashes, increased risk of blood clots, and potential ocular toxicity. Aromatase inhibitors are associated with loss of bone density, increased risk of fractures, and cardiovascular issues. Other endocrine therapies, such as fulvestrant, may cause injection site reactions, fatigue, and gastrointestinal symptoms. These treatments aim to reduce the risk of cancer recurrence but come with a range of potential side effects that should be discussed with a healthcare provider.

What prior FDA approvals exist?

For the treatment of hormone receptor-positive (HR+), HER2-negative advanced/metastatic breast cancer, the FDA has approved several drugs. Notable among these are the CDK4/6 inhibitors such as palbociclib, ribociclib, and abemaciclib, which are often used in combination with hormonal therapies like letrozole or fulvestrant. These treatments target pathways involved in cell cycle regulation and hormone receptor signaling, similar to the investigational drug RGT-419B.

What other types of research exist?

Promising alternatives to RGT-419B for hormone receptor-positive breast cancer include tamoxifen, raloxifene, and aromatase inhibitors like anastrozole. Tamoxifen and raloxifene are selective estrogen receptor modulators (SERMs) with proven efficacy in reducing the risk of estrogen receptor-positive breast cancer. Aromatase inhibitors, such as anastrozole, are also effective in reducing recurrence rates in postmenopausal women with hormone receptor-positive breast cancer. These alternatives have established safety profiles and are widely used in clinical practice.

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RGT-419B + Hormonal Therapy for Breast Cancer

Phase 1

Recruiting

Research Sponsored by Regor Pharmaceuticals Inc.

Eligibility Criteria Checklist

Specific guidelines that determine who can or cannot participate in a clinical trial

Must have

HR+, HER2- tumor by most recent biopsy with measurable disease

ECOG Performance Status 0 to 1

Must not have

Presence of visceral metastases with severe organ dysfunction as evidence by signs and symptoms, laboratory studies, lymphangitic spread and/or rapid progression of disease

Major surgery, chemotherapy, targeted therapy, experimental agents, or radiation within 14 days prior to Cycle 1, Day 1

Timeline

Screening 3 weeks

Treatment Varies

Follow Up through study completion, an average of 1 year

Awards & highlights

No Placebo-Only Group

Summary

This trial is testing a new oral drug, RGT-419B, for patients with advanced breast cancer who haven't responded to other treatments. The study aims to see if the drug can safely stop cancer cell growth.

Who is the study for?

This trial is for adults with HR+, HER2- advanced or metastatic breast cancer who've had no more than one prior chemotherapy in this setting and less than three lines of CDK4/6i therapy. Participants must have an ECOG Performance Status of 0 to 1, indicating they are fully active or restricted in physically strenuous activity but ambulatory.

What is being tested?

The study tests RGT-419B, a new oral medication, alone or combined with hormonal therapy. It's a phase I trial focusing on safety, how the body processes the drug (pharmacokinetics), and its initial effectiveness against certain types of breast cancer that progressed after previous treatments.

What are the potential side effects?

While specific side effects aren't listed here, typical ones may include reactions related to immune system activation such as fatigue, nausea, skin issues; hormone-related changes; and potential impacts on liver function. Side effects will be closely monitored due to the early stage of testing.

Eligibility Criteria

Inclusion Criteria

You may be eligible if you check “Yes” for the criteria below

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My tumor is HR positive, HER2 negative, and can be measured.

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I am fully active or can carry out light work.

Exclusion Criteria

You may be eligible for the trial if you check “No” for criteria below:

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My cancer has spread to my organs, causing severe problems.

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I haven't had major surgery or cancer treatment in the last 14 days.

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I have not had radiation to more than a quarter of my bone marrow and my organs are functioning well.

Timeline

Screening ~ 3 weeks3 visits

Treatment ~ Varies

Follow Up ~ through study completion, an average of 1 year

Screening ~ 3 weeks

Treatment ~ Varies

Follow Up ~through study completion, an average of 1 year

This trial's timeline: 3 weeks for screening, Varies for treatment, and through study completion, an average of 1 year for reporting.

Treatment Details

Study Objectives

Study objectives can provide a clearer picture of what you can expect from a treatment.

Primary study objectives

Safety & Tolerability - Number of subjects with Dose-Limiting Toxicities (DLTs) at each cohort dose level in singlet and doublet therapy

Secondary study objectives

Day 1 and steady-state PK assessment of RGT-419B and major metabolites - Accumulation rate after multiple doses

Day 1 and steady-state PK assessment of RGT-419B and major metabolites - Area Under Concentration-Time Curve (AUC0-t)

Brain Diseases, Metabolic

+7 more

Other study objectives

Symptom Burden

Awards & Highlights

No Placebo-Only Group

All patients enrolled in this study will receive some form of active treatment.

Trial Design

2Treatment groups

Experimental Treatment

Group I: Arm BExperimental Treatment1 Intervention

RGT-419B in combination with Hormonal Therapy

Group II: Arm AExperimental Treatment1 Intervention

RGT-419B given alone as monotherapy

0 / 5Eligibility criteria met

Research Highlights

Information in this section is not a recommendation. We encourage patients to speak with their healthcare team when evaluating any treatment decision.

Mechanism Of Action

Side Effect Profile

Prior Approvals

Other Research

The most common treatments for hormone receptor-positive breast cancer include endocrine therapies and targeted therapies. Endocrine therapies, such as aromatase inhibitors and selective estrogen receptor modulators (SERMs), work by reducing estrogen levels or blocking estrogen receptors, thereby inhibiting the growth of hormone-dependent cancer cells. Targeted therapies, like CDK4/6 inhibitors, work by interfering with specific molecules involved in cancer cell proliferation. These mechanisms are crucial for breast cancer patients as they provide more personalized and effective treatment options, potentially leading to better outcomes and fewer side effects compared to traditional chemotherapy.

Extending the clinical benefit of endocrine therapy for women with hormone receptor-positive metastatic breast cancer: differentiating mechanisms of action.Resistance to endocrine therapy in breast cancer: exploiting estrogen receptor/growth factor signaling crosstalk.