Study of IEV407 as Single Agent or in Combination in Patients With Advanced HR+/HER2- Breast Cancer

NCT07604571 | Not Yet Recruiting Phase 1 DMC FDA Drug

• 2 other identifiers: CIEV407A121012025-522707-26
• Study Type: interventional
• Target: 194
• Locations: 0 countries
• Sites: N/A

Brief Summary

The purpose of this study is to evaluate the safety, tolerability and preliminary activity of IEV407 as a single agent and in combination with endocrine therapy (fulvestrant or letrozole) in patients with advanced hormone receptor positive (HR+), human epidermal growth factor receptor 2 negative (HER2-negative) breast cancer.

Conditions

Advanced HR+/HER2- Breast Cancer

Keywords

IEV407; HR+/HER2- advanced breast cancer; letrozole; fulvestrant

Outcome Measures

Primary Outcomes (4)

• Incidence and severity of dose-limiting toxicities (DLTs)

  Number of participants with DLTs. A DLT is defined as an adverse event or abnormal laboratory value of Common Terminology Criteria for Adverse Events (CTCAE) grade 3 or higher, including death, unless clearly and incontrovertibly assessed as due to disease, disease progression, inter-current illness/injury, concomitant medications, or extraneous causes, that occurs within the first 28 days of treatment with IEV407 in the dose escalation parts or in the expansion part of IEV407 in combination with fulvestrant with the exceptions described in the study protocol.

  28 days

• Incidence and severity of Adverse Events (AEs) and Serious Adverse Events (SAEs)

  Number of participants with AEs and SAEs, including changes in laboratory values, vital signs and echocardiograms (ECGs) qualifying and reported as AEs.

  Up to approximately 2 years

• Frequency of dose interruptions, reductions and discontinuations

  Number of participants with dose adjustments (interruptions, reductions, or permanent discontinuation) as a measure of tolerability.

  Up to approximately 2 years

• Dose intensity

  Dose intensity defined as the ratio of actual cumulative dose received and actual duration of exposure.

  Up to approximately 2 years

Secondary Outcomes (8)

• Best Overall Response (BOR)

  Up to approximately 2 years

• Overall Response Rate (ORR)

  Up to approximately 2 years

• Disease Control Rate (DCR)

  Up to approximately 2 years

• Clinical Benefit Rate (CBR)

  Up to approximately 2 years

• Duration of Response (DOR)

  Up to approximately 2 years

Study Arms (5)

Dose escalation: IEV407 single agent

EXPERIMENTAL

IEV407 single agent

Drug: IEV407

Dose escalation: IEV407 + fulvestrant

EXPERIMENTAL

IEV407 in combination with fulvestrant

Drug: IEV407; Drug: Fulvestrant

Dose escalation: IEV407 + letrozole

EXPERIMENTAL

IEV407 in combination with letrozole

Drug: IEV407; Drug: Letrozole

Dose expansion, recommended dose (RD)-1: IEV407 + fulvestrant

EXPERIMENTAL

IEV407 in combination with fulvestrant

Drug: IEV407; Drug: Fulvestrant

Dose expansion, RD-2 (optional dose optimization): IEV407 + fulvestrant

EXPERIMENTAL

IEV407 in combination with fulvestrant

Drug: IEV407; Drug: Fulvestrant

Interventions

IEV407 DRUG

Oral administration

Dose escalation: IEV407 + fulvestrant; Dose escalation: IEV407 + letrozole; Dose escalation: IEV407 single agent; Dose expansion, RD-2 (optional dose optimization): IEV407 + fulvestrant; Dose expansion, recommended dose (RD)-1: IEV407 + fulvestrant

Fulvestrant DRUG

Intramuscular injection. Approved medication.

Also known as: Faslodex

Dose escalation: IEV407 + fulvestrant; Dose expansion, RD-2 (optional dose optimization): IEV407 + fulvestrant; Dose expansion, recommended dose (RD)-1: IEV407 + fulvestrant

Letrozole DRUG

Oral administration. Approved medication.

Also known as: Femara

Dose escalation: IEV407 + letrozole

Eligibility Criteria

• Age: 18 Years - 100 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age ≥ 18 years old
• Patients with one of the following indications:
• Dose escalation (IEV407 single agent and in combination with fulvestrant or letrozole):
• HR+/HER2- aBC with disease progression on or following, or have been intolerant to, at least one line of endocrine-based therapy in combination with a CDK4/6 inhibitor and at least one additional line of systemic therapy in the unresectable/metastatic setting and not be a candidate for any available standard therapy, in the investigator's judgement.
• \- Dose expansion of IEV407 in combination with fulvestrant: HR+/HER2- aBC with disease progression on or following, or have been intolerant to, endocrine-based therapy in combination with a CDK4/6 inhibitor. They must not have received more than two prior lines of endocrine-based therapy in the unresectable/metastatic setting. Prior cytotoxic chemotherapy and/or antibody-drug conjugate therapies in the unresectable/metastatic setting are not allowed.

You may not qualify if:

• Patients with inadequate bone marrow and/or organ functions with out-of-range laboratory values.
• Impaired cardiac function or clinically significant cardiac disease.
• Concurrent use of hormone replacement therapy.
• Women of childbearing potential who are unwilling to use highly effective contraception methods, pregnant or nursing women.
• For the combination treatment of IEV407 with fulvestrant or letrozole: Patients with symptomatic visceral disease or any disease burden that makes the patient ineligible for endocrine-based therapy.

Sponsors & Collaborators

• Novartis Pharmaceuticals: lead

MeSH Terms

Interventions

Fulvestrant; Letrozole

Intervention Hierarchy (Ancestors)

Estradiol; Estrenes; Estranes; Steroids; Fused-Ring Compounds; Polycyclic Compounds; Estradiol Congeners; Gonadal Steroid Hormones; Gonadal Hormones; Hormones; Hormones, Hormone Substitutes, and Hormone Antagonists; Nitriles; Organic Chemicals; Triazoles; Azoles; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds

Central Study Contacts

Novartis Pharmaceuticals

CONTACT

1-888-669-6682; novartis.email@novartis.com

Novartis Pharmaceuticals

CONTACT

+41613241111

Study Design

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

Study Record Dates

• First Submitted: May 18, 2026
• First Posted: May 22, 2026
• Study Start (Estimated): June 12, 2026
• Primary Completion (Estimated): June 8, 2032
• Study Completion (Estimated): June 8, 2032
• Last Updated: May 22, 2026

Record last verified: 2026-05

Data Sharing

• IPD Sharing: Will not share