# Molecular Imaging of CD46

> **NIH NIH R21** · UNIVERSITY OF CALIFORNIA, SAN FRANCISCO · 2022 · $201,875

## Abstract

PROJECT SUMMARY
CD46 is highly expressed in multiple cancers, including both adenocarcinoma and
neuroendocrine types of metastatic castration resistant prostate cancer (mCRPC). Its expression
on normal tissue is generally low except for placental trophoblasts during pregnancy and to a
lesser degree the prostate epithelium. An anti-CD46 antibody-drug conjugate (ADC) originally
developed in the Liu lab is now in phase I trials at five US centers for mCRPC. UCSF is the leading
test site (led by significant contributor Dr. Rahul Aggarwal) and the first patient has been dosed.
An important challenge for this type of therapy is the appropriate selection of CD46-positive
patients who will likely respond to therapy. One method to assay CD46 positivity would be through
tissue sampling. However, biopsies do not reflect target expression in all lesions but rather the
characteristic of a specific tumor metastatic lesion. In contrast, non-invasive molecular imaging
using anti-CD46 radiotracers will allow for whole body assessment of antigen expression and
consequently identification of patients who are likely to respond to this novel therapy. CD46 has
been very recently discovered as a novel target of advanced prostate cancer; therefore, there is
a gap in fundamental information about whole body expression of CD46, relationship between its
expression and tumor growth and metastasis formation. Moreover, as a recently discovered
target, molecular imaging of CD46 could contribute to understand specific molecular alterations
related to CD46 expression.
The goal of this proposal is the technical development of a platform for molecular imaging of
CD46. We will develop a panel of radiopharmaceuticals capable of non-invasively imaging CD46.
This platform will not only has the potential to identify mCRPC patients that will likely respond to
CD46 ADC and other emerging therapies but also to explore CD46 expression in other tumor
types with special attention to those that currently has very poor prognosis and survival. The
information gather in this project may play an important role in the development on new therapies.

## Key facts

- **NIH application ID:** 10374152
- **Project number:** 5R21EB029695-02
- **Recipient organization:** UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
- **Principal Investigator:** Kondapa Naidu Bobba
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $201,875
- **Award type:** 5
- **Project period:** 2021-04-01 → 2024-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10374152

## Citation

> US National Institutes of Health, RePORTER application 10374152, Molecular Imaging of CD46 (5R21EB029695-02). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10374152. Licensed CC0.

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