Could your own tumor become a vaccine? new trial aims to train the immune system against breast cancer

NCT ID NCT03804944

First seen Jun 25, 2026 · Last updated Jun 27, 2026 · Updated 1 time

Summary

This phase 2 trial is testing a new approach for post-menopausal women with HR+HER2- breast cancer. Participants receive standard hormone therapy plus focal radiation, and some also get the immunotherapy drug pembrolizumab and an immune booster (CDX-301). The goal is to see if this combination can turn the tumor into a personalized vaccine that triggers a stronger immune response. The study will check for safety and measure how well the tumor shrinks or disappears before surgery.

What this could mean

Our plain-language read of the trial. This is informational only — not medical advice or a prediction.

Active substance

Pembrolizumab (immunotherapy drug) and CDX-301 (immune booster), combined with focal radiation therapy

What this could lead to

If successful, this approach could turn a patient's own tumor into a vaccine that helps the immune system fight the cancer more effectively, potentially improving outcomes for HR+ breast cancer.

What could go wrong

This is a small, early-phase trial (100 participants) testing safety and initial effectiveness. The combination may cause side effects, and it's unknown if it will work better than standard treatment.

Disclaimer Read more

This is a summary of the original study . Summaries may miss details or leave out important information. Before applying or accepting participation, make sure you have read and understood the full study. Curemydisease.com takes no responsibility whatsoever for anything missed, misunderstood, or acted upon as a result of our summary — we know it does not capture everything.

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Conditions

The condition(s) this trial relates to.

breast cancer breast neoplasm hormone receptor-positive breast cancer

As listed by the trial registrant

The condition terms exactly as the trial's registrant entered them.

Contacts and locations

Study contacts

  • Contact

    Phone: •••-•••-•••• Email: •••••@•••••

Locations

  • Brooklyn Methodist Hospital - NewYork Presbyterian

    RECRUITING

    New York, New York, 11215, United States

    Contact

    Contact Phone: •••-•••-•••• Email: •••••@•••••

    Contact Phone: •••-•••-•••• Email: •••••@•••••

  • Cedars-Sinai Medical Center

    WITHDRAWN

    Los Angeles, California, 90048, United States

  • Houston Methodist Cancer Center

    RECRUITING

    Houston, Texas, 77030, United States

    Contact Phone: •••-•••-•••• Email: •••••@•••••

    Contact

  • Icahn School of Medicine at Mt Sinai

    WITHDRAWN

    New York, New York, 10027, United States

  • New York Presbyterian Hospital - Queens

    RECRUITING

    New York, New York, 10065, United States

    Contact

    Contact Phone: •••-•••-•••• Email: •••••@•••••

    Contact Phone: •••-•••-•••• Email: •••••@•••••

  • UPMC Hillman Cancer Center

    WITHDRAWN

    Pittsburgh, Pennsylvania, 15232, United States

  • UT Southwestern Medical Center

    RECRUITING

    Dallas, Texas, 75390-9179, United States

    Contact

    Contact Phone: •••-•••-•••• Email: •••••@•••••

  • Weill Cornell Medicine New York Presbyterian Hospital

    RECRUITING

    New York, New York, 10065, United States

    Contact Phone: •••-•••-•••• Email: •••••@•••••

    Contact