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A young mother who had beaten breast cancer once got some devastating news. The cancer had returned. Her prognosis seemed grim. Available medicines didn't offer much hope. But what if her doctors could enlist her own immune system to fight the cancer in ways never before possible?
That's just what they're trying to do, said Dr. Jessica Treviño Jones, a breast medical oncologist at UT Health San Antonio's Mays Cancer Center. She's also the patient's treating physician.
Mays is the only site in Texas participating in a phase 2 study of an investigational therapy called STAR0602, which is designed to activate and then sustain the immune system's ability to recognize and destroy cancer cells. Treviño Jones's patient is the first clinical trial participant to be enrolled and treated at UT Health San Antonio Multispecialty and Research Hospital.
While oncologists have been harnessing the power of the human immune system for years, STAR0602 is unique because it teaches a more lasting lesson. Other therapies work only while being administered, and then the effects diminish rapidly. STAR0602 builds immune memory, so the body continues attacking cancer cells between infusions.
"It's the same principle behind vaccines," Treviño Jones said. "It is engaging and training parts of a patient's immune system to recognize and kill their cancer."
The trial pairs STAR0602 with sacituzumab govitecan, which is FDA-approved and sold as Trodelvy. It's a drug that delivers chemotherapy directly to cancer cells while sparing healthy tissue. Trodelvy and STAR0602 work well together because when Trodelvy kills cancer, it flags the tumor as a target for the immune system. STAR0602 then trains the activated immune system to remember what the cancer cells look like, so it will keep killing them.
"We are combining them to help the immune system," Treviño Jones explained. "So the power is not just at the time we give them medicine, but in the in-between spaces."
STAR0602 is being offered to patients whose cancers haven't responded to standard therapies, people like Treviño Jones's patient. This is a population that typically has tried all of the available medications, and they haven't worked well or at all. Treviño Jones said the trial therapy is changing the narrative. "We are tearing down the rhetoric where you need to find the right medicine that kills cancer," she said. "We are advancing care by bringing forward what we know we've always needed, which is something stronger. It is letting the body fight cancer in the in-between."
Early results are showing measurable immune response between treatment doses, which is just what researchers like Treviño Jones and their patients want to see. "It is hope," she said. "Not false hope, true hope. It is hope for patients who have never had hope before."
The trial therapy triggers a significant immune response, so patients require up to 72 hours of inpatient monitoring after each infusion. That limits the trial to institutions with both a dedicated cancer center and full hospital capabilities, like Mays Cancer Center and UT Health San Antonio Multispecialty and Research Hospital. About two dozen hospitals across the U.S., Canada, and Europe are participating.
The study is currently in phase 2, focused on evaluating the therapy's effectiveness while assessing for potential toxicity. The next step would be phase 3 trials and ultimately FDA approval. The current trial is focused on breast and colon cancer, but Treviño Jones said it has potential for any solid tumor that the immune system can be trained to recognize.
This research is the future of cancer care, according to Treviño Jones, who is also an associate professor in the Division of Hematology and Medical Oncology at the UT Health San Antonio Long School of Medicine. "As cancer treatments continue to evolve, as technology continues to get better, we will continue to lean into the immune system and help our body find ways to fight cancer."
Patients interested in learning whether they qualify to participate in this clinical trial can inquire at UT Health San Antonio’s Find-a-Study research portal.
