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RecruitingNCT06998407AVZO-023-1001Updated Aug 10, 2026

ORION-1: Study of AVZO-023 as a Single Agent and in Combination With AVZO-021, and/or Endocrine Therapy in Advanced Solid Tumors

A Phase 1/2 interventional study of AVZO-021 and Fulvestrant in HR+/HER2- Breast Cancer and HR+, HER2-, Advanced Breast Cancer, sponsored by Avenzo Therapeutics, Inc.. Recruiting at 16 sites in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-08-10.

Sponsored by Avenzo Therapeutics, Inc. · Phase 1/2, Interventional, and Treatment

From the registry’s dates

  • Started Aug 2025; still recruiting 1 year 2 months later.

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Phase
Phase 1/2
Study type
Interventional
Enrollment
380
Allocation
Non-randomized
Ages
18 Years and older
Sex
All
01

Study summary

This study, the first clinical trial of AVZO-023, aims to determine the safety, tolerability, pharmacokinetics (PK), pharmacodynamics, maximum tolerated dose, and anti-tumor effects of AVZO-023 in patients with advanced solid tumors. AVZO-023 is an oral medication that inhibits cyclin-dependent kinase 4 (CDK4).

Read the detailed description

AVZO-023 is an oral, potent, and selective inhibitor of CDK4. AVZO-021 is an oral, potent, and selective inhibitor of CDK2 that is currently being investigated in a global Phase 1/2 study in patients with advanced hormone receptive positive (HR+)/human epidermal growth factor receptor 2 negative (HER2-) breast cancer (NCT05867251).

In Phase 1, the safety and tolerability of AVZO-023 in patients with HR+/HER2- locally advanced or metastatic breast cancer (mBC) will be assessed. The goal of Phase 1 is to determine the MTD/preliminary RP2D of AVZO-023 for use as monotherapy and in combination with AVZO-021 with or without endocrine therapy (ET).

Phase 2 will assess the antitumor activity and confirm the RP2D of AVZO-023 in combination therapy in patients with HR+/HER2- locally advanced or mBC.

02

Conditions studied

  • HR+/HER2- Breast Cancer
  • HR+, HER2-, Advanced Breast Cancer

Browse trials for

03

In context

Breast Neoplasms

14,832 studies on the registry are indexed under Breast Neoplasms; 3,320 are open to participants now.

This study's planned enrollment of 380 is above the median of 72 across 10,903 interventional studies indexed under Breast Neoplasms.

Browse Breast Neoplasms studies →

Lead sponsor

Avenzo Therapeutics, Inc. is the lead sponsor of 4 studies on the registry; 4 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

Eligibility criteria

Key Inclusion Criteria:

  • Male or female aged ≥ 18 years old at screening with (ECOG) 0-1 and > 3 months
  • Patients with or cytologically proven advanced of preferred indications
  • (as assessed by investigator using v1.1) is preferred in Phase 1 dose escalation, unless otherwise specified in the protocol, and in all patients in Phase 2. Bone only disease is allowed in dose escalation.
  • Agree to provide molecular test report results to confirm eligibility and and/or fresh biopsy, as applicable
  • Adequate renal, liver, and bone marrow function

Key Exclusion Criteria:

  • Patients should not have received any prior selective CDK (CDK2, CDK4, CDK2/4, CDK2/4/6) inhibitors
  • Has known active (have either previously untreated intracranial CNS metastasis or previously treated intracranial central nervous system (CNS) with radiologically documented new or progressing CNS lesions) or
  • Other concurrent invasive malignancy or a prior invasive malignancy for which treatment was completed within 3 years before the first dose on study except for adequately treated basal cell or squamous cell skin cancer, carcinoma in situ, or colorectal adenomatous polyps
  • Last anticancer treatment within 2 weeks (4 weeks for biologic, immunotherapy or ADC) or 5 half-lives of the drug, whichever is shorter, prior to first dose on study
  • Major surgery within 4 weeks prior to first dose on study
  • Have received radiotherapy with a limited field of radiation for palliation within 7 days of the first dose of study treatment, except for patients receiving whole brain radiotherapy, which must be completed at least 4 weeks prior to the first dose of study treatment. Patients must have recovered from all radiation-related toxicities, not require , and not have active radiation pneumonitis. Patients who received radiation of >25% of bone marrow are excluded.
  • Strong or moderate inhibitors or inducers within 2 weeks or 5 half-lives of the drug, whichever is shorter, prior to first dose on study
  • History of serious cardiovascular conditions within 6 months prior to first dose on study
  • Unresolved toxicities from prior therapy greater than Grade 1 (per version 5.0) (with exceptions of alopecia, vitiligo, and ≤ Grade 2 peripheral neuropathy) prior to the first dose on study
  • History of drug-induced pneumonitis/interstitial lung disease
  • Confirmed loss of function mutation or deletion of Rb1 gene
  • Previous high-dose chemotherapy requiring stem cell rescue
Terms in these criteria, in plain language(14)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

ECOG performance status

A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.

0
Fully active, no restrictions.
1
Limited in strenuous activity, but walking and able to do light work, such as housework or office work.
2
Walking and able to look after yourself, but unable to work; up and about more than half of waking hours.
3
Able to look after yourself only in part; in bed or a chair more than half of waking hours.
4
Unable to look after yourself at all; in bed or a chair all day.

Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.

Life expectancy

The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.

Histologically or cytologically confirmed

The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).

Your pathology report is the document that shows this.

Cancer (malignancy)

Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.

Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.

Measurable disease

The amount of disease can be tracked with a defined measurement, so the study can see whether it shrinks or grows. It might be a tumour measured on a scan or, in some blood cancers such as myeloma, a marker measured in blood or urine.

The criteria or the study team say which measurement counts — having no tumour visible on a scan does not by itself rule you out.

RECIST

The standard rules for measuring tumours on CT or MRI scans, to tell whether a cancer is shrinking, stable or growing during treatment.

“Measurable disease per RECIST 1.1” usually means at least one tumour 10 mm or more at its longest on a CT scan, or a lymph node 15 mm or more across its short axis.

Biopsy and archival tissue

A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.

Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.

Investigational drug or device

A drug or device being studied in a clinical trial.

It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.

Brain metastases

Cancer deposits in the brain from a cancer that started elsewhere in the body (CNS metastases include the spinal cord).

Studies differ: some leave out any brain metastases, some accept ones treated and stable for some weeks. Check what this study allows.

Metastases

Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.

Leptomeningeal disease

Cancer that has spread to the leptomeninges, the thin layers covering the brain and spinal cord, and the fluid between them. It is not the same as brain metastases.

Criteria often treat it separately, and many studies leave it out even where treated brain metastases are allowed.

Corticosteroids (steroids)

Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.

Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.

CYP3A (CYP3A4) inhibitors and inducers

CYP3A is a group of enzymes, mainly CYP3A4, in the liver and gut that break down many medicines. Some medicines, supplements and foods (grapefruit, St John’s wort) slow them down or speed them up, which changes how much of a study drug stays in the body.

Studies list them so they can be avoided or switched; bring a list of everything you take, including supplements.

CTCAE grade

The US National Cancer Institute’s scale of how severe an adverse event is — any unwanted medical event during a study, such as a symptom, an illness or an abnormal test result, whether or not a treatment caused it. Whether it did is judged separately.

1
Mild.
2
Moderate.
3
Severe.
4
Life-threatening.
5
Death due to the event.

“Side effects of earlier treatment resolved to grade 1 or less” means they have settled to mild or gone.

05

Study design

Phase
Phase 1 / Phase 2
Primary purpose
Treatment
Allocation
Non-randomized
Intervention model
Sequential assignment
Masking
None (open label)
Enrollment
380 participants (estimated)

Study arms

  • Experimental
    Phase 1, monotherapy (Part 1A) and food effect

    Escalating doses of twice daily, oral AVZO-023 in 28-day cycles, with addition of fulvestrant

    Drug: Fulvestrant · Drug: AVZO-023

  • Experimental
    Phase 1, combination (Parts 1B)

    Escalating doses of twice daily, oral AVZO-023 in combination with once daily, oral AVZO-021 in 28-day cycles, with addition of fulvestrant

    Drug: AVZO-021 · Drug: Fulvestrant · Drug: AVZO-023

  • Experimental
    Phase 1, combination (Parts 1C)

    Escalating doses of twice daily, oral AVZO-023 in combination with once daily, oral AVZO-021, with once daily, oral letrozole in 28-day cycles

    Drug: AVZO-021 · Drug: Letrozole · Drug: AVZO-023

  • Experimental
    Phase 2, combination (Cohorts 2A, 2B, 2C, and 2D)

    Oral doses of AVZO-023 in 28-day cycles at the RP2D determined in Part 1B/1C, in combination with: 2A) letrozole 2B) fulvestrant 2C) AVZO-021 plus fulvestrant 2D) AVZO-021 plus letrozole

    Drug: AVZO-021 · Drug: Fulvestrant · Drug: Letrozole · Drug: AVZO-023

Interventions

  • DrugAVZO-021

    AVZO-021 is an oral selective CDK2 inhibitor

  • Antineoplastic agent, estrogen receptor antagonist

    Also known as: Faslodex

  • Antineoplastic agent, aromatase inhibitor

    Also known as: Femara

  • DrugAVZO-023

    AVZO-023 is an oral selective CDK4 inhibitor

06

What researchers measure

Primary outcomes

  1. Occurrence of Dose Limiting Toxicities (DLTs) during the first cycle (Phase 1)

    Number of participants with DLTs assessed for severity using CTCAE v5.0 criteria will be summarized by dose level.

    Time frame: Cycle 1 (28 Days)

  2. Number of Participants with Treatment Emergent Adverse Events (TEAEs) and lab abnormalities (Phase 1)

    Time frame: From baseline until end of study treatment or study completion (approximately 2 years)

  3. Determine the Maximum Tolerated Dose (MTD) and/or Recommended Phase 2 Dose (RP2D) (Phase 1)

    Time frame: Approximately 16 months

  4. Objective Response Rate (ORR) (Phase 2)

    Defined as the proportion of patients with a confirmed Complete Response (CR) or Partial Response (PR), as determined by the investigator by radiographic disease assessment according to RECIST v1.1.

    Time frame: From baseline through disease progression or study completion (approximately 2 years)

Secondary outcomes

  1. Objective Response Rate (ORR) (Phase 1)

    Time frame: From baseline through disease progression or study completion (approximately 2 years)

  2. Duration of response (DOR) (Phase 1 and Phase 2)

    Defined as the time from the first confirmed response to radiologic/objective progression.

    Time frame: From baseline through time to event on study or study completion (approximately 2 years)

  3. Progression Free Survival (PFS) (Phase 1 and Phase 2)

    Defined as the time from study drug treatment to death or disease progression, as determined by the investigator by radiographic disease assessment according to RECIST v1.1.

    Time frame: From baseline through time to event on study or study completion (approximately 2 years)

  4. Overall Survival (OS) (Phase 1 and Phase 2)

    Defined as the time from study drug treatment initiation to death from any cause.

    Time frame: Approximately 76 months

  5. Disease control rate (DCR) (Phase 1 and Phase 2)

    Defined as the proportion of patients who achieve tumor relief (CR or PR) and stable disease (SD) after treatment; calculated as the sum of CR, PR, and SD.

    Time frame: From baseline through disease progression or study completion (approximately 2 years)

  6. Clinical benefit rate (CBR) (Phase 1 and Phase 2)

    Defined as the percentage of advanced cancer patients who achieve CR, PR, or at least six months of SD after treatment.

    Time frame: From baseline through disease progression or study completion (approximately 2 years)

  7. PK Parameters: Maximum plasma concentration (Cmax) (Phase 1)

    Time frame: Day 1 and Day 15 of Cycle 1 (each cycle is 28 days)

  8. PK Parameters: Time to maximum plasma concentration (Tmax) (Phase 1)

    Time frame: Day 1 and Day 15 of Cycle 1 (each cycle is 28 days)

  9. PK Parameters: Elimination half-life (t1/2) (Phase 1)

    Time frame: Day 1 and Day 15 of Cycle 1 (each cycle is 28 days)

  10. PK Parameters: Area under the plasma concentration-time curve from time 0 to last measurable concentration (AUC 0-last) (Phase 1)

    Time frame: Day 1 and Day 15 of Cycle 1 (each cycle is 28 days)

  11. Determination of RP2D (Phase 2)

    Time frame: Approximately 16 months

  12. Number of Participants with Treatment Emergent Adverse Events (TEAEs) and lab abnormalities (Phase 2)

    Time frame: From baseline until end of study treatment or study completion (approximately 2 years)

07

Study locations

16 of 16 sites recruiting
  • Avenzo Therapeutics Recruiting Site
    Los Angeles, California 90025, United States
    Recruiting
    • Avenzo Therapeutics · Contact
  • Avenzo Therapeutics Recruiting Site
    Los Angeles, California 90095, United States
    Recruiting
    • Avenzo Therapeutics · Contact
  • Avenzo Therapeutics Recruiting Site
    New Haven, Connecticut 06519, United States
    Recruiting
    • Avenzo Therapeutics · Contact
  • Avenzo Therapeutics Recruiting Site
    Orlando, Florida 32827, United States
    Recruiting
    • Avenzo Therapeutics · Contact
  • Avenzo Therapeutics Recruiting Site
    Sarasota, Florida 34232, United States
    Recruiting
    • Avenzo Therapeutics · Contact
  • Avenzo Therapeutics Recruiting Site
    Tampa, Florida 33612, United States
    Recruiting
    • Avenzo Therapeutics · Contact
  • Avenzo Therapeutics Recruiting Site
    Boston, Massachusetts 02215, United States
    Recruiting
    • Avenzo Therapeutics · Contact
  • Avenzo Therapeutics Recruiting Site
    New York, New York 10016, United States
    Recruiting
    • Avenzo Therapeutics · Contact
  • Avenzo Therapeutics Recruiting Site
    Cleveland, Ohio 44106, United States
    Recruiting
    • Avenzo Therapeutics · Contact
  • Avenzo Therapeutics Recruiting Site
    Columbus, Ohio 43221, United States
    Recruiting
    • Avenzo Therapeutics · Contact
  • Avenzo Therapeutics Recruiting Site
    Nashville, Tennessee 37203, United States
    Recruiting
    • Avenzo Therapeutics · Contact
  • Avenzo Therapeutics Recruiting Site
    Fort Worth, Texas 76104, United States
    Recruiting
    • Avenzo Therapeutics · Contact
  • Avenzo Therapeutics Recruiting Site
    Houston, Texas 77030, United States
    Recruiting
    • Avenzo Therapeutics · Contact
  • Avenzo Therapeutics Recruiting Site
    San Antonio, Texas 78229, United States
    Recruiting
    • Avenzo Therapeutics · Contact
  • Avenzo Therapeutics Recruiting Site
    Fairfax, Virginia 22031, United States
    Recruiting
    • Avenzo Therapeutics · Contact
  • Avenzo Therapeutics Recruiting Site
    Seattle, Washington 98109, United States
    Recruiting
    • Avenzo Therapeutics · Contact
08

Timeline

Tracking since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reachedSimilar studies: half by the dot; the band is the middle halfHalf of similar studies reached it by the dot; the band is the middle half, from a quarter to three quarters

Started Aug 2025 (actual). Primary completion is estimated for Aug 2028, 36 months after the start.

Of 161 industry-sponsored phase 1/2 interventional studies under Breast Neoplasms, half reached primary completion within 59 months of starting (the median), counting those still running; a quarter within 44 and three quarters within 75. This study's planned 36 months is below that.

Counting every sponsor, half of 327 studies reached it within 61 months; a quarter within 45 and three quarters within 88.

How these figures are worked out, and which studies are left out of them.

Registered
May 22, 2025
First posted
May 31, 2025
StartActual
Aug 20, 2025
Primary completionEst.
Aug 2028
CompletionEst.
Aug 2030
Last update
Aug 10, 2026
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
No changes since tracking began. The registry record was last updated on Aug 10, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
09

Registry details

Key details

Study ID
NCT06998407
Lead sponsor
Avenzo Therapeutics, Inc.
Responsible party
Sponsor
First posted
May 31, 2025
Start date
Aug 20, 2025
Primary completion
Aug 2028 (estimated)
Completion
Aug 2030 (estimated)
Last update
Aug 10, 2026

Study contacts

Medical Information
Contact
ClinicalTrials@avenzotx.com
(858) 239-2944

Oversight

Data monitoring committee
No
FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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