Updated May 2026 · ClinicalTrials.gov

RECRUITINGPhase 1INTERVENTIONAL

A Study of BTX-A51 in People With Advanced Solid Tumor and Breast Cancer

Q: Who can participate in NCT04872166?

Eligibility for this trial depends on the specific inclusion and exclusion criteria set by the sponsor. The plain-English summary above translates the most important criteria into accessible language; the official clinical text is preserved in the collapsible section underneath. Whether you fit any specific trial is a medical decision your doctor needs to confirm — bring the trial information to your treating physician for a full review against your medical history.

Q: How do I contact the trial site for NCT04872166?

Contact information registered with ClinicalTrials.gov is shown in the sidebar of this page. Before reaching out, confirm with your treating physician that this trial is appropriate for your situation. The trial site will then walk you through the screening process to determine final eligibility.

Q: Is participating in a clinical trial safe?

Clinical trials in the United States are regulated by the FDA and overseen by Institutional Review Boards (IRBs) that review the protocol for safety. Risk varies by trial — Phase 1 studies test new treatments in humans for the first time, while Phase 3 trials use treatments that have already passed earlier safety screening. The informed consent document for any specific trial details the known risks and what to expect. Discuss those risks with your physician before deciding whether to participate.

Q: Where can I verify the data on this page?

Every detail on this page comes directly from the ClinicalTrials.gov API. Click "View on ClinicalTrials.gov" in the sidebar to see the official, unmodified record. The federal record is always authoritative; this page is a structured presentation with a plain-English eligibility translation. For background on how clinical trials are regulated, see the FDA drug approval process documentation.

An Open Label, Escalating Multiple Dose Study to Evaluate the Safety, Toxicity, and Pharmacokinetics of BTX A51 Alone and in Combination With Fulvestrant in Subjects With Advanced Solid Tumors and Estrogen Receptor Positive, Human Epidermal Growth Factor Receptor 2 Negative Metastatic Breast Cancer

A Study of BTX-A51 in People With Advanced Solid Tumor and Breast Cancer (NCT04872166) is a Phase 1 interventional studying Advanced Solid Tumor and Metastatic Breast Cancer, sponsored by Edgewood Oncology Inc.. RECRUITING as of the most recent ClinicalTrials.gov update. Talk to your doctor before contacting the trial site.

About This Trial

This is a multicenter, open label, nonrandomized, sequential dose escalation/dose ranging, multiple dose study designed to evaluate the safety, toxicity, and PK as well as preliminary efficacy of BTX-A51 alone and in combination with fulvestrant in subjects with advanced solid tumors. The study will be done in three phases, described below. Phase 1a (Dose Escalation Phase): The Phase 1a portion is designed to determine the dose limiting toxicities (DLTs), maximum tolerated dose (MTD), and recommended Phase 2 dose (RP2D) of orally administered BTX-A51. BTX-A51 will be administered once daily on a weekly schedule of 5 days on/2 days off. Dose escalation will proceed according to a modified 3+3 design. Each cycle will consist of 28 days (4 weeks), and the DLT observation period will be the first cycle (i.e., 28 days after initiation of dosing). A DLT may be observed in no more than 0 out of 3 or 1 out of 6 subjects who have completed the DLT observation period before the next cohort initiates accrual. Barring DLT, sequential dose escalation of BTX-A51 is planned with up to a total of 6 dose levels; on the basis of these an MTD will be identified. The MTD is defined as the highest dose level with a subject incidence of DLTs of 0 or 1 out of 6 during the first 28 days of study drug dosing. A minimum of 6 subjects needs to be treated at a dose level before this dose level can be deemed as the MTD. Phase 1b (Monotherapy Dose Ranging Phase): Dose expansion may begin when the RP2D has been determined. Up to 40 additional subjects at each of the 2 dose levels will be enrolled to evaluate safety and preliminary efficacy of BTX-A51 in subjects with estrogen receptor positive (ER+), human epidermal growth factor receptor 2 negative (HER2-), GATA3 mutant (mt) and wild-type (wt) metastatic breast cancer (mBC). Dosing in this phase of the study consists of the first cycle of therapy (i.e., 28 days). Phase 1c (Combination Safety Phase): The Phase 1c portion will evaluate the safety and tolerability of orally administered BTX-A51 at two dose levels combined with fulvestrant. The first combo cohort may be initiated after DEC review of the 6 subject lead-in phase of the high dose monotherapy cohort in Phase 1b. Dose escalation will proceed according to a 3+3 design. Each cycle will consist of 28 days (4 weeks), and the DLT observation period will be the first cycle (i.e., 28 days after initiation of dosing).

What Stage of Research Is This?

Phase 1 trials test a new treatment for the first time in humans, focusing on safety, dosing, and how the body processes the drug. For Advanced Solid Tumor, a Phase 1 study typically enrolls a small number of participants — often healthy volunteers or patients who have exhausted standard treatment options. Phase 1 results determine whether a treatment moves into larger Phase 2 efficacy studies.

This trial is currently recruiting participants. The sponsor has registered the study with ClinicalTrials.gov as actively enrolling, which means new applicants who meet the eligibility criteria can be considered for screening. Trial status can change between updates — confirm current recruiting status with the study contact before traveling for a screening visit.

Target enrollment of 112 participants puts this in the typical range for a Phase 2-style efficacy study or a moderate Phase 3 trial in a focused Advanced Solid Tumor subpopulation. At this scale, the study has enough statistical power to detect a clear treatment effect but is not the largest cohort in the field.

Who May Be Eligible (Plain English)

Who May Qualify: - Demonstration of understanding and voluntarily signing of an willing to sign a consent form form - Age ≥ 18 years - Histologically or cytologically documented, incurable or metastatic solid tumor that is refractory to or intolerant of all standard therapy or for which no standard therapy is available - Phase 1b and 1c only: diagnosed by tissue sample (biopsy-confirmed) diagnosis of ER+, HER2- mBC not amenable to resection or radiation therapy with curative intent. - Measurable disease per Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST v1.1). - your organs (liver, kidneys, etc.) are working well enough based on blood tests - Females of childbearing age must not be pregnant at time of Screening/beginning of treatment and agree to either abstain from sexual intercourse or use highly effective methods of contraception (for up to 3 months after last dose of study drug) - Males sexually active with a woman of childbearing age must agree to use barrier method of birth control during and after the study (up to 3 months after last dose of study drug) Who Should NOT Join This Trial: - Life expectancy \<3 months, as determined by the Investigator. - Treatment with any local or systemic antineoplastic therapy (including chemotherapy, hormonal therapy, or radiation) within 3 weeks prior to first dose of BTX-A51 - Chronic use of corticosteroids in excess of 10 mg daily of prednisone or equivalent within 4 weeks prior to first dose of BTX-A51 - Major trauma or major surgery within 4 weeks prior to first dose of BTX-A51. - Adverse events from prior anti-cancer therapy that have not resolved to Grade ≤1 except for alopecia or Grade ≤2 immunotherapy-related thyroid toxicity. - History of, or known, central nervous system (CNS) disease involvement, or prior history of NCI CTCAE Grade ≥3 drug-related CNS toxicity. - Clinically significant cardiac disease - Active uncontrolled systemic fungal, bacterial, mycobacterial, or viral infection ...See full criteria on ClinicalTrials.gov Always talk to your doctor about whether this trial is right for you.

These are translations of the protocol\'s inclusion and exclusion criteria, simplified for patients and caregivers. The original clinical text appears below. Eligibility is ultimately confirmed by the trial site\'s screening process — this summary is a starting point for a conversation with your doctor, not a final determination.

Original Eligibility Criteria

View original clinical language

Inclusion Criteria: * Demonstration of understanding and voluntarily signing of an informed consent form * Age ≥ 18 years * Histologically or cytologically documented, incurable or metastatic solid tumor that is refractory to or intolerant of all standard therapy or for which no standard therapy is available * Phase 1b and 1c only: Histologically confirmed diagnosis of ER+, HER2- mBC not amenable to resection or radiation therapy with curative intent. * Measurable disease per Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST v1.1). * Adequate organ function * Females of childbearing age must not be pregnant at time of Screening/beginning of treatment and agree to either abstain from sexual intercourse or use highly effective methods of contraception (for up to 3 months after last dose of study drug) * Males sexually active with a woman of childbearing age must agree to use barrier method of birth control during and after the study (up to 3 months after last dose of study drug) Exclusion Criteria: * Life expectancy \<3 months, as determined by the Investigator. * Treatment with any local or systemic antineoplastic therapy (including chemotherapy, hormonal therapy, or radiation) within 3 weeks prior to first dose of BTX-A51 * Chronic use of corticosteroids in excess of 10 mg daily of prednisone or equivalent within 4 weeks prior to first dose of BTX-A51 * Major trauma or major surgery within 4 weeks prior to first dose of BTX-A51. * Adverse events from prior anti-cancer therapy that have not resolved to Grade ≤1 except for alopecia or Grade ≤2 immunotherapy-related thyroid toxicity. * History of, or known, central nervous system (CNS) disease involvement, or prior history of NCI CTCAE Grade ≥3 drug-related CNS toxicity. * Clinically significant cardiac disease * Active uncontrolled systemic fungal, bacterial, mycobacterial, or viral infection * Known positive test result for human immunodeficiency virus (HIV) or acquired immune deficiency syndrome (AIDS) * Active hepatitis C virus (HCV) or hepatitis B virus (HBV) * Second primary malignancy that has not been in remission for greater than 3 years * Any serious underlying medical (e.g., pulmonary, renal, hepatic, gastrointestinal, or neurological) or psychiatric condition (e.g., alcohol or drug abuse, dementia or altered mental status) or any issue that would limit compliance with study requirements * Pregnant, lactating, or breastfeeding. * Participation or plans to participate in another interventional clinical study.

Treatments Being Tested

DRUG

BTX-A51

One 28 day cycle of treatment will consist of 4 weeks of treatment with a weekly dosing schedule of up to 5 days per weekf.

Locations (6)

Trial sites listed on ClinicalTrials.gov for this study. Site activation status can vary — confirm with the specific site before traveling for a screening visit.

Florida Cancer Specialists

Lake Mary, Florida, United States

Florida Cancer Specialists

Sarasota, Florida, United States

The Linder Research Center at The Christ Hospital

Cincinnati, Ohio, United States

SCRI Oncology Partners

Nashville, Tennessee, United States

Tennessee Oncology, PLLC

Nashville, Tennessee, United States

The University of Texas MD Anderson Cancer Center

Houston, Texas, United States

How to Talk to Your Doctor About This Trial

Bring the printable summary of this trial — including the NCT ID (NCT04872166), the sponsor (Edgewood Oncology Inc.), and the key eligibility criteria — to your next appointment. Your doctor can review the inclusion and exclusion criteria against your medical history, lab values, and current treatments to assess whether you are likely to qualify. They can also help you weigh whether trial participation makes sense alongside your existing care plan.

Useful questions to walk through together: What does the trial protocol require beyond standard care? How long is the active treatment phase, and how long is follow-up? Are there study visits at sites I can reach? Who pays for the trial-specific procedures, and who pays for standard-of-care portions? See our 25 questions to ask about clinical trials guide for a more complete checklist.

Authoritative Sources

The official record for this trial lives on ClinicalTrials.gov — the federal registry maintained by the National Library of Medicine at NIH. For background on how this trial fits into the FDA approval pathway, see the FDA drug approval process. For oncology-specific guidance for patients considering trials, the National Cancer Institute publishes patient-oriented overviews. International trial registries are aggregated by the WHO ICTRP.

Frequently Asked Questions

What is the NCT04872166 clinical trial studying?

Who can participate in NCT04872166?

Eligibility for this trial depends on the specific inclusion and exclusion criteria set by the sponsor. The plain-English summary above translates the most important criteria into accessible language; the official clinical text is preserved in the collapsible section underneath. Whether you fit any specific trial is a medical decision your doctor needs to confirm — bring the trial information to your treating physician for a full review against your medical history.

How do I contact the trial site for NCT04872166?

Contact information registered with ClinicalTrials.gov is shown in the sidebar of this page. Before reaching out, confirm with your treating physician that this trial is appropriate for your situation. The trial site will then walk you through the screening process to determine final eligibility.

Is participating in a clinical trial safe?

Clinical trials in the United States are regulated by the FDA and overseen by Institutional Review Boards (IRBs) that review the protocol for safety. Risk varies by trial — Phase 1 studies test new treatments in humans for the first time, while Phase 3 trials use treatments that have already passed earlier safety screening. The informed consent document for any specific trial details the known risks and what to expect. Discuss those risks with your physician before deciding whether to participate.

Where can I verify the data on this page?

Every detail on this page comes directly from the ClinicalTrials.gov API. Click "View on ClinicalTrials.gov" in the sidebar to see the official, unmodified record. The federal record is always authoritative; this page is a structured presentation with a plain-English eligibility translation. For background on how clinical trials are regulated, see the FDA drug approval process documentation.

How This Page Is Built

Every field on this page is pulled directly from the ClinicalTrials.gov API v2 — no estimates, no proxies. The plain-English eligibility translation is generated from the original protocol text and reviewed for fidelity to the underlying clinical criteria. The original clinical text remains visible in the collapsible section above so users and clinicians can verify the translation. Read the full methodology for the data pipeline and known limitations.

Source: ClinicalTrials.gov API v2 record for NCT04872166. Maintained by the National Library of Medicine at NIH. Public domain. Cite as: "TrialFinderData. NCT04872166. Data: ClinicalTrials.gov."

Medical disclaimer: This page is informational, not medical advice. Talk to your doctor about whether a clinical trial is right for you.

Last updated 2026-05-08 · Data from ClinicalTrials.gov.