# Integrating Ipilimumab Immunotherapy with Approved Treatment Strategies in CRPC

> **NIH NIH P50** · UNIVERSITY OF TX MD ANDERSON CAN CTR · 2020 · $285,493

## Abstract

PROJECT SUMMARY (Project 1) 
The mainstay therapy for castration-resistant prostate cancer (CRPC) consists of agents targeting the 
androgen receptor (AR) signaling pathway and chemotherapies, which induce antitumor responses, and in 
select men a vaccine and a radiopharmaceutical bone-targeting therapy. The responses with all of these 
therapies tend to be short-lived. Conversely, treatment with the cytotoxic T-lymphocyte antigen 4 (CTLA-4)– 
targeting drug, ipilimumab, which promotes enhanced T-cell responses and generates memory immune 
responses, has led to durable regression of metastatic disease and an overall survival benefit. A recent phase 
3 trial of ipilimumab in patients with CRPC demonstrated dramatic responses in a subset of them 
and improved survival in those with favorable clinical characteristics, who also tend to have good responses to 
therapies targeting the AR signaling pathway. Previous studies demonstrated that inhibition of AR signaling 
has positive effects on the immune system. We hypothesize that patients with cancers that regress with 
therapies targeting AR signaling will benefit from the addition of anti-CTLA-4 (ipilimumab) immunotherapy. In 
addition, given the lack of imaging capabilities to differentiate between tumor growth and tumor infiltration by 
immune cells as a result of immunotherapy, we propose to develop radiolabeled antibody imaging to evaluate 
tumor responses to immunotherapy. We aim to rationally integrate anti-CTLA-4 (ipilimumab) immunotherapy 
with agents targeting the AR signaling pathway to provide durable clinical benefit with improved survival in 
patients with prostate cancer, and utilize novel imaging techniques to accurately identify tumor responses. 
In this project, we will identify molecular changes associated with clinical outcomes of anti-CTLA-4 (ipilimumab) 
immunotherapy for prostate cancer by examining matched tumor and peripheral blood specimens obtained in 
recently completed clinical trials. We will perform in-depth examination of the specimens using 
immunohistochemistry, immunofluorescence, flow cytometry, gene expression studies, and serum cytokine 
analyses. We will prospectively evaluate the most promising molecular determinants in our novel clinical trial 
with the aim of linking the interactions between the immune system and the AR signaling pathway. Finally, 
because our group has identified other immunologic molecules that may be targeted with radiolabeled 
antibodies for imaging, we propose to evaluate this possibility in murine models to provide data for future 
clinical trials. Our proposed studies will provide data to enable integration of anti-CTLA-4 (ipilimumab) 
immunotherapy into a treatment strategy for prostate cancer that induces durable responses and improves 
overall survival, with the goal of curing the disease.

## Key facts

- **NIH application ID:** 10005150
- **Project number:** 5P50CA140388-10
- **Recipient organization:** UNIVERSITY OF TX MD ANDERSON CAN CTR
- **Principal Investigator:** JAMES P ALLISON
- **Activity code:** P50 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $285,493
- **Award type:** 5
- **Project period:** 2009-09-02 → 2023-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10005150

## Citation

> US National Institutes of Health, RePORTER application 10005150, Integrating Ipilimumab Immunotherapy with Approved Treatment Strategies in CRPC (5P50CA140388-10). Retrieved via AI Analytics 2026-06-15 from https://api.ai-analytics.org/grant/nih/10005150. Licensed CC0.

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