An experimental molecule has completely eradicated breast tumors in mice with just one injection — a stunning result that could reshape how we treat breast cancer. While more research is needed to confirm its safety and effectiveness in humans, the discovery marks a major leap forward.
Breast cancer remains the second leading cause of cancer-related deaths among women. Roughly 70% of cases are ERα+ (estrogen receptor alpha–positive), meaning the tumor cells grow in response to estrogen. Current therapies — such as aromatase inhibitors and drugs like tamoxifen, fulvestrant, and elacestrant — slow tumor growth but rarely eliminate it entirely. They also require years of continuous treatment, often accompanied by heavy side effects that make long-term use difficult.
Enter ErSO-TFPy, a new molecule that could change everything. In a recent study published in ACS Central Science, researchers demonstrated that a single injection of ErSO-TFPy eradicated large tumors in mice within days — a result scientists call “remarkable.”
ErSO-TFPy: how it works and why it’s so promising
ErSO-TFPy belongs to a new class of compounds that specifically target ERα+ cancer cells. It works by disrupting ionic balance inside the tumor cells, triggering extreme stress and a rapid, necrotic death. In mouse experiments, one intravenous injection caused the complete regression of large tumors — between 500 and 1,500 mm³.
Unlike traditional treatments that merely slow tumor growth, ErSO-TFPy destroys the cancer cells entirely within a few days. Further research has shown that its effect depends on activating the TRPM4 ion channel, which causes a massive influx of ions into the cancer cell — essentially bursting it. Because this mechanism is specific to ERα+ cells, healthy tissues remain unaffected, suggesting the drug could significantly limit side effects.
The studies were conducted on mice. © MP-AI, Adobe Stock (AI-generated image)
A new hope for patients who’ve run out of options
This potential therapy comes with several game-changing advantages:
- One injection is enough: unlike current treatments requiring years of daily doses.
- Kills, not just slows: where standard anti-estrogen drugs halt growth, ErSO-TFPy rapidly kills cancer cells.
- Lower resistance risk: its powerful and fast action could prevent mutations that lead to treatment resistance.
- Fewer side effects: a one-time therapy means fewer issues with tolerance and adherence.
Preclinical results are highly encouraging, though clinical trials are still necessary to test the molecule’s safety and effectiveness in humans. If those studies confirm the findings, ErSO-TFPy could become a groundbreaking therapy for thousands of women with advanced or treatment-resistant ERα+ breast cancer.
For now, this discovery opens a new frontier in cancer therapy — one where treatments are more targeted, better tolerated, and potentially more effective than anything currently available.
Stéphanie Le Guillou
Health journalist
With a PhD in Pharmacy and Cancer Biology, this expert has worked in hospitals, the pharmaceutical industry, and a healthcare communication agency.
Today, she pursues her passion for writing, creating medical content for the general public. She regularly contributes to Futura’s Health section, striving to make medical information more accessible.