Drug In Development In San Antonio Targets Recurrent Breast Cancer

Sep 5, 2017

Some San Antonio scientists are developing a new drug that could help save the lives of women whose breast cancer comes back. Recurrent tumors are common and often deadly. This new agent is showing great promise.

A noisy centrifuge, a carefully controlled incubator, a bench full of busy scientists working on cancer cell lines -- all can be found in a lab is where basic science and medical need intersect.

Researcher Ratna Vadlamudi, Ph.D., of UT Health San Antonio is fighting a killer. "There are several types of breast cancer. We are specifically looking at estrogen responsive breast cancer," he explained.

These are genetically modified mice that have no immune system. Scientists can take human breast tumors and grow them in the mice for testing of new drug agents.
Credit Wendy Rigby / Texas Public Radio

Treating breast cancer can be tricky. Once the cancer is removed and initial therapies like chemo and radiation are over, women with estrogen receptive positive cancer are often placed on Tamoxifen or aromatase inhibitors. Those are drugs that can cut the rate of the cancer coming back by 50 percent. But that means half of the women who survive this kind of cancer do have a recurrence -- new tumors that often spread and can be deadly.

Dr. Vadlamudi opened the cages of lab animals with small growths on their bodies -- "immune compromised mice that can take human tumors and grow them," he said. These mice that have helped him develop a molecule that blocks the estrogen receptor signaling that occurs in drug-resistant tumors. And that molecule can be delivered in a pill.

"The beauty of this molecule, it is orally available," Vadlamudi stated. "That means you can take a tablet. We tested in the mice giving it to them by mouth and it’s working."

Lorena Aguilar was diagnosed with cancer in her right breast in 2016.
Credit Andrew Brenner, MD / UT Health Cancer Center

As a medical oncologist, Andrew Brenner, MD, has seen a lot of cancer that doctors thought they had beaten, but it came back. "We need alternate forms of therapy so that we can do a better job of preventing the breast cancer from coming back," he added.

Lorena Aguilar, 46, is one of his Dr. Brenner’s patients. "We were able to beat this and I got a second chance," she said.

Aguilar has estrogen receptor-positive breast cancer and fears recurrence. That’s why she takes Tamoxifen. "That is one of my biggest fears. So I make sure I take it every day. You know, trying to do everything I can to prevent this from coming back."

But Aguilar knows she might need a different drug in the future. And she gets emotional when she talks about medical advances with their genesis in San Antonio. "I’m truly blessed that we live in a city that there’s so much research going on here. You know, that they’re trying to find cures for those women that the medications might not be working for to try to save more lives," she emphasized.

Cancer cell lines are kept in incubators in this lab at the South Texas Research Facility.
Credit Wendy Rigby / Texas Public Radio

Meanwhile, in this lab at the South Texas Research Facility, there’s no time to celebrate early success. Next up, animal trials in higher species -- perhaps rats and dogs -- to test toxicity and effectiveness. And then, phase one clinical trials in people that would likely take place in San Antonio.

Having a wife and sister with this kind of cancer has served as an inspiration to Dr. Vadlamudi. "It is an effort of personal and the science. It makes you more motivated," he stressed. "If the tumor is coming back, this drug will play an important role in blocking its growth."

The researchers have applied for a patent on their lab-created molecule and published early results. Still, the road to getting a new drug on the market will be long and expensive.