News Release

Promising compound kills range of hard-to-treat cancers by targeting a previously undiscovered vulnerability

ERX-41, developed by UT Health San Antonio scientists, exploits a previously unrecognized weakness in breast cancer and other solid tumors

Peer-Reviewed Publication

University of Texas Health Science Center at San Antonio

Radna Vadlamudi, PhD

image: Radna Vadlamudi, PhD, of The University of Texas Health Science Center at San Antonio, is part of a team reporting the promising effects of a compound against a range of difficult-to-treat cancers. The study, published June 2, 2022, in Nature Cancer, points to the compound's targeting of a previously unrecognized vulnerability in several cancers, including triple-negative breast cancer. view more 

Credit: UT Health San Antonio

SAN ANTONIO (June 2, 2022) – A compound, developed by a team including scientists from The University of Texas Health Science Center at San Antonio, kills a range of hard-to-treat cancer types in petri dishes and animal models by targeting a previously unexploited vulnerability, a new study reports. The findings, published in Nature Cancer, could eventually lead to new drugs to fight these cancers, which currently have few effective treatments.

“We identified a critical vulnerability in multiple cancers and have validated our findings in multiple cancer cell types and animal models,” said study leader Ratna Vadlamudi, PhD, professor of obstetrics and gynecology at UT Health San Antonio and a member of the Mays Cancer Center, home to UT Health San Antonio MD Anderson Cancer Center. “The range of cell lines and xenografts in which the compound has been shown to work is compelling and indicates that it is targeting a fundamental vulnerability in cancer cells.” Xenografts are human tumors grown in mouse models for research purposes.

The Vadlamudi lab studies breast and ovarian cancer progression, including in therapy resistance, with a goal to developing small-molecule inhibitors for therapy-resistant cancers. In 2017, he and his colleagues identified a compound called ERX-11 that targets the estrogen receptor (ER), a protein that drives the vast majority of breast cancers. From a screen of chemical analogs of ERX-11, the researchers identified that a compound called ERX-41 not only killed ER-positive cancers in petri dishes, but also readily killed triple-negative breast cancers (TNBCs), including more than 20 distinct TNBC cell lines. TNBC is a cancer subtype lacking receptors for estrogen, progesterone and human epidermal growth factor 2, and for which there is a paucity of targeted treatments.

The researchers expanded these studies to show ERX-41 had activity against a large number of human tumors grown from several of these cell lines in mouse models. In addition, ERX-41 was potent against patient-derived xenografts, as well, causing shrinkage of these human tumors grown in mouse models without affecting normal breast cells or causing any discernible toxicity in these animals. “The safety profile and high therapeutic index of this compound is particularly notable and bodes well for clinical translation,” Dr. Vadlamudi said.

Other experiments showed that in addition to ER-positive breast cancers and TNBC, ERX-41 is also effective against other cancer types with elevated endoplasmic reticulum stress, including pancreatic, glioblastoma and ovarian cancers, which all have few effective treatments. The endoplasmic reticulum is a structure in many cell types that performs assorted functions, including manufacture of proteins.

This work was performed in collaboration with scientists at UT Dallas (led by Dr. JungMo Ahn) and UT Southwestern Medical Center at Dallas (led by Dr. Ganesh Raj). ERX-41 and the related portfolio have been licensed to Dallas-based EtiraRx, which plans to move these drugs into clinical trials in early 2023.

Other researchers from UT Health San Antonio who contributed to this study include Drs. Suryavathi Viswanadhapalli, Mengxing Li, Gangadhara R Sareddy, Uday P Pratap, Zexuan Liu, Hui Yan, Zhenming Xu, Susan E Weintraub and Rajeshwar Rao Tekmal.

This research was funded by grants from the National Institutes of Health (CA223828-01 and NIH-NCI P30 CA054174).

Targeting LIPA independent of its lipase activity is a therapeutic strategy in solid tumors via induction of endoplasmic reticulum stress

Xihui Liu, Suryavathi Viswanadhapalli, Shourya Kumar, Tae-Kyung Lee, Andrew Moore, Shihong Ma, Liping Chen, Michael Hsieh, Mengxing Li, Gangadhara R Sareddy, Karla Parra, Eliot Blatt, Tanner C. Reese, Yuting Zhao1, Annabel Chang, Hui Yan, Zhenming Xu, Uday P Pratap, Zexuan Liu, Carlos M. Roggero, Zhenqiu Tan, Susan T. Weintraub, Yan Peng, Rajeshwar R Tekmal, Carlos L. Arteaga, Jennifer Lippincott-Schwartz, Ratna K. Vadlamudi, Jung-Mo Ahn, Ganesh V. Raj

First published: Nature Cancer, June 2, 2022

The University of Texas Health Science Center at San Antonio (UT Health San Antonio) is a primary driver for San Antonio’s $42.4 billion health care and biosciences sector, the city’s largest economic generator. Driving substantial economic impact with its five professional schools, a diverse workforce of 7,200, an annual operating budget of more than $1 billion and a clinical practice that provides more than 2 million patient visits each year, UT Health San Antonio plans to add more than 1,500 higher-wage jobs over the next five years to serve San Antonio, Bexar County and South Texas. UT Health San Antonio is the largest research university in South Texas with an annual research portfolio of approximately $350 million. To learn about the many ways “We make lives better®,” visit

The Mays Cancer Center, home to UT Health San Antonio MD Anderson Cancer Center, is one of only four National Cancer Institute-designated Cancer Centers in Texas. The Mays Cancer Center provides leading-edge cancer care, propels innovative cancer research and educates the next generation of leaders to end cancer in South Texas. Visit

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