A Vaccine (STEMVAC) With Standard Endocrine-Based Therapy or Chemotherapy for the Treatment of Metastatic Hormone Receptor Positive, HER2 Negative Breast Cancer

Summary

This phase II trial studies how well a vaccine, STEMVAC, works in combination with standard endocrine-based therapy (ET) with a CDK4/6 targeted drug therapy, or with the chemotherapy drug capecitabine, in treating patients with hormone receptor (HR)-positive, HER2-negative breast cancer that has spread from where it first started (primary site) to other places in the body (metastatic). STEMVAC is designed to target proteins that cancer cells use when they become more aggressive and start to spread, and it is believed to work by boosting the immune system to recognize and destroy the invader tumor cells that are causing the disease. Standard ET is treatment that adds, blocks, or removes hormones in order to slow or stop the growth of cancer. Standard CDK4/6 inhibitors, including abemaciclib, may stop the growth of tumor cells and may kill them by blocking some of the enzymes needed for cell growth. Capecitabine is in a class of medications called antimetabolites. It is taken up by tumor cells and breaks down into fluorouracil, a substance that kills tumor cells. Giving STEMVAC in combination with standard ET or chemotherapy may be an effective treatment for metastatic HR positive, HER2 negative breast cancer.

Conditions

• Anatomic Stage IV Breast Cancer AJCC v8
• Metastatic HER2-Negative Breast Carcinoma
• Metastatic Hormone Receptor-Positive Breast Carcinoma

Interventions

BIOLOGICAL

CD105/Yb-1/SOX2/CDH3/MDM2-polyepitope Plasmid DNA Vaccine

Given ID

DRUG

Capecitabine

Given SOC capecitabine

PROCEDURE

Computed Tomography

Undergo CT or ultrasound-guided biopsies

DRUG

Cyclin-Dependent Kinase 4 Inhibitor

Given SOC CDK4/6i

DRUG

Cyclin-Dependent Kinase 6 Inhibitor

Given SOC CDK4/6i

DRUG

F-18 16 Alpha-Fluoroestradiol

Undergo FES PET

DRUG

Hormone Therapy

Given SOC ET

PROCEDURE

Positron Emission Tomography

Undergo PET or FES PET

PROCEDURE

Biopsy Procedure

Undergo image-guided biopsies

PROCEDURE

Biospecimen Collection

Undergo collection of blood samples

DRUG

Abemaciclib

Given SOC abemaciclib

Sponsors & Collaborators

• University of Washington

  lead OTHER

Principal Investigators

• Natasha Hunter, MD · Fred Hutch/University of Washington Cancer Consortium

Study Design

Allocation

NON_RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Model

PARALLEL

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2025-11-17

Primary Completion

2028-07-31

Completion

2028-12-31

FDA Drug

Yes

Countries

• United States

Study Locations