Study of GVV858 as a Single Agent or in Combination With Endocrine Therapy in Patients With HR+/HER2- Breast Cancer and Other Advanced Solid Tumors

Official record

Identifier

NCT07288359

Recruiting locations

countries

United StatesCzechiaDenmarkFranceGermanyItalyJapanSingaporeSpainTaiwan

Interventions studied

GVV858FulvestrantLetrozole

Lead sponsor

Novartis Pharmaceuticals

Target enrolment

205 participants

Study type

INTERVENTIONAL

Phase

Phase 1/2

Status

Recruiting

First posted

Dec 17, 2025

Last updated on the registry

Jul 30, 2026

Age

18 Years

Sex

ALL

Study contact

The official record lists a study contact. Contact details are published there and are intentionally not copied to this page.

Eligibility criteria

Reproduced verbatim from the official record. Eligibility is decided by the study team, never by this page.

Inclusion Criteria:

* Age ≥ 18 years old.
* Patients with one of the following histologically or cytologically confirmed advanced cancers:

Phase I (patients with one of the following cancers, from whom no standard therapy is available or appropriate in the judgment of the investigator):

* HR+/HER2- advanced breast cancer (aBC) with disease progression on or following at least one line of hormone-based therapy in combination with a CDK4/6i and at least one additional line of systemic therapy for metastatic disease.
* Locally advanced or metastatic cancer with a CCNE1 amplification. For dose expansion only: no more than 3 prior lines of therapy for advanced or metastatic disease.
* Metastatic castration-resistant prostate adenocarcinoma, with no documented neuroendocrine component, castrate level of testosterone, and no more than 3 prior lines of systemic therapy for metastatic disease.

Phase II:

* HR+/HER2- aBC with disease progression on or after an endocrine therapy in combination, with a CDK4/6 inhibitor for advanced disease with no more than 2 lines of endocrine therapy and no prior cytotoxic chemotherapy or antibody-drug-conjugate for advanced disease.

  \- Measurable disease as determined by RECIST v1.1.
* BC only: If no measurable disease is present, then at least one predominantly lytic bone lesion must be present that can be accurately assessed at baseline and is suitable for repeated assessment.
* metastatic Castration-Resistant Prostate Cancer (mCRPC) only: If no measurable disease is present per PCWG3 modified RECIST, then at least 1 metastatic lesion must be present on bone scan imaging.

Exclusion Criteria:

* Patients with inadequate bone marrow and/or organ functions with out-of-range laboratory values.
* Clinically significant, uncontrolled heart disease and/or cardiac repolarization abnormality including myocardial infarction (MI), coronary artery bypass graft (CABG), long QT syndrome, or risk factors for Torsades de Pointes (TdP).
* Presence of symptomatic central nervous system (CNS) metastases or CNS metastases that require local therapy or increasing doses of corticosteroids within 2 weeks prior to study entry.
* Patients with symptomatic visceral disease, including visceral crisis.
* For patients with BC: Patient is concurrently using hormone replacement therapy.
* Women of childbearing potential who are unwilling to use highly effective contraception methods, pregnant or nursing women.

Other protocol-defined inclusion/exclusion criteria may apply.