Combination Therapy May Help Overcome Barrier in Early-Stage Prostate Cancer Treatment

Pairing Immunotherapy with Hormone Therapy Shows Promise in Overcoming 'Cold' Prostate Tumors

Published on Feb. 26, 2026

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A new study led by Mayo Clinic researchers has revealed a potentially groundbreaking approach to treating early-stage prostate cancer. The study found that combining a next-generation immunotherapy with standard hormone therapy before surgery can help overcome a significant hurdle in prostate cancer treatment - the 'cold' nature of prostate tumors that makes them resistant to immunotherapy.

Why it matters

Historically, immunotherapy has struggled to effectively treat prostate cancer because prostate tumors often lack sufficient immune cell infiltration, making it difficult for the body's own defenses to attack the cancer. This lack of immune response is described as the tumor being 'immunologically cold'. The new combination therapy approach aims to address this challenge by using an immunotherapy that can deplete regulatory T cells (Tregs), which suppress the immune system and hinder its ability to fight cancer.

The details

The study involved 24 men with high-risk, localized prostate cancer. Researchers found that adding the investigational Fc-enhanced anti-CTLA-4 antibody (BMS-986218) immunotherapy to standard androgen deprivation therapy (ADT) significantly reduced Treg levels within the tumors compared to hormone therapy alone. Patients whose tumors experienced the greatest reduction in Tregs were more likely to remain cancer-free during follow-up, suggesting a strong correlation between Treg depletion and positive treatment outcomes.

  • The study was published in Cell Reports Medicine in February 2026.

The players

Mayo Clinic

A nonprofit organization committed to clinical practice, education, and research. It is one of the leading healthcare providers in the United States.

Casey Ager, Ph.D.

A cancer immunology researcher at Mayo Clinic and the first author of the study.

BMS-986218

An investigational Fc-enhanced anti-CTLA-4 antibody used as the immunotherapy in the study.

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What they’re saying

“Selective Treg depletion in tumors has been a long-sought goal of the oncology field. We had the opportunity to test a drug that's been engineered to better deplete Tregs than the drugs we previously had.”

— Casey Ager, Ph.D., Cancer immunology researcher at Mayo Clinic (Cell Reports Medicine)

What’s next

Researchers are exploring combining Treg-depleting immunotherapies with other cancer treatments, such as chemotherapy or radiation therapy, to further enhance anti-tumor responses. The goal is to create synergistic effects that maximize treatment efficacy. Additionally, researchers are investigating the potential of immunotherapy in treating metastatic castration-resistant prostate cancer (mCRPC).

The takeaway

This study represents a significant step forward in prostate cancer treatment, as it demonstrates the potential of a combination therapy approach to overcome the 'cold' nature of prostate tumors and improve patient outcomes. The identification of potential biomarkers is also crucial for developing personalized immunotherapy approaches and tailoring treatment plans for optimal effectiveness.