The drug prevented migration and had other effects we're still investigating
A drug long prescribed for a rare lung condition has revealed an unexpected capacity to interrupt one of cancer's most lethal maneuvers — the ability to spread. Researchers at the University of São Paulo found that ambrisentan, already approved for pulmonary hypertension, significantly reduced tumor migration and extended survival across multiple cancer types in laboratory and animal studies. The discovery invites a familiar question in medicine: whether a molecule shaped for one disease might quietly hold answers for another, and whether the path from animal model to human benefit will prove as promising as the early evidence suggests.
- Cancer's deadliest feature — metastasis — remains the primary driver of mortality, and any drug that meaningfully disrupts it commands urgent attention.
- Ambrisentan cut metastasis to the liver and lungs by 47% in aggressive breast cancer mouse models and extended median survival by roughly 30%, results that are difficult to dismiss as marginal.
- The drug attacks on two fronts simultaneously: blocking tumor cells from migrating to distant tissues and cutting off the new blood vessel formation tumors depend on to grow.
- Because ambrisentan is already approved for human use and taken orally, the barrier to clinical testing is lower than for most experimental cancer therapies — trials pairing it with chemotherapy are now being prepared.
- Researchers are moving carefully, warning against unsupervised use and acknowledging that laboratory promise has not yet translated to proven human benefit.
A drug already in clinical use for pulmonary hypertension — a rare lung condition often linked to autoimmune diseases like lupus — has shown striking potential against cancer's most dangerous capability: the ability to spread. In studies published in Scientific Reports, researchers at the University of Biomedical Sciences Institute at the University of São Paulo found that ambrisentan significantly reduced tumor cell migration and blocked the formation of new blood vessels that feed tumor growth, across pancreatic, ovarian, breast, and leukemia cell lines.
The mechanism centers on the drug's blockade of the endothelin type A receptor, a protein present on blood vessel linings and immune cells. Led by Otávio Cabral Marques, the team found this single blockade appeared to disrupt cancer on multiple fronts at once — an effect whose full scope is still being mapped.
The animal results were notable. Mice treated with ambrisentan before and after injection of aggressive breast cancer cells saw metastasis to the liver and lungs fall by 47 percent, with median survival rising by roughly 30 percent over untreated controls. Researchers deliberately began treatment before tumor implantation to reflect real clinical conditions, where preventive therapy often precedes full disease establishment.
The drug's existing approval for human use and its oral administration offer practical advantages rare in experimental oncology. Even so, Marques is proceeding with caution, preparing clinical trials to test ambrisentan alongside chemotherapy rather than assuming animal results will transfer directly to people. The specific cancer type for those trials has yet to be chosen, and direct tumor application is also being explored as a way to enhance efficacy.
Marques was clear that unsupervised use carries real risks, particularly for pregnant women. The convergence of findings — disrupted migration, starved blood supply, extended survival — suggests the drug warrants serious clinical investigation, but the longer road from laboratory to proven human therapy remains ahead.
A drug already prescribed for a rare lung disease has shown unexpected power against cancer's deadliest trick: the ability to spread. In laboratory tests and animal studies, ambrisentan—used clinically to treat pulmonary hypertension, a condition often triggered by autoimmune diseases like lupus—significantly hampered tumor cells' capacity to migrate to distant tissues and establish themselves there. The findings, published in Scientific Reports, emerged from work across four major cancer types: pancreatic, ovarian, breast, and leukemia.
The mechanism is elegant in its simplicity. Ambrisentan blocks the endothelin type A receptor, a protein found on the inner lining of blood vessels and on immune cells. Researchers at the University of São Paulo's Biomedical Sciences Institute, led by Otávio Cabral Marques, discovered that this blockade does more than just slow tumor cell movement—it appears to starve tumors of the new blood vessels they need to grow, a process called neoangiogenesis. "The drug prevented migration of tumor cells to other tissues and had other effects we're still investigating," Marques said. The full scope of the drug's anti-cancer action remains under study, but early evidence suggests it works on multiple fronts simultaneously.
The animal data proved striking. When researchers injected aggressive breast cancer cells into mice and treated them with ambrisentan for two weeks before and two weeks after injection, metastasis to the liver and lungs dropped by 47 percent. Median survival in treated animals increased by roughly 30 percent compared to untreated controls. These are not trivial gains in a disease where metastasis is the primary killer. The researchers chose to begin treatment before tumor implantation specifically to mirror the human clinical scenario, where patients often receive preventive therapy before cancer has fully established itself.
What makes this discovery particularly intriguing is that ambrisentan is already approved for human use and can be taken by mouth—a significant practical advantage over many experimental cancer drugs. Yet the researchers are not rushing to assume the drug will work in people the way it worked in cells and mice. Marques is now preparing clinical trials at his institute to test whether cancer patients receiving ambrisentan alongside chemotherapy recover better than those receiving chemotherapy alone. The specific cancer type to be studied has not yet been selected, and researchers are also exploring whether applying the drug directly to tumors might amplify its effects.
The path from laboratory promise to clinical reality is long and uncertain. The drug's benefits in cancer treatment remain unproven in humans, and Marques emphasized that use without medical supervision could cause harm, particularly in pregnant women. Still, the convergence of findings—reduced cell migration across multiple cancer lines, blocked blood vessel formation, extended survival in animal models—suggests ambrisentan may deserve a place in the oncology toolkit. The next phase will tell whether a drug developed to ease breathing in one disease can help patients with another survive longer.
Citas Notables
The drug prevented migration of tumor cells to other tissues and had other effects we're still investigating.— Otávio Cabral Marques, University of São Paulo's Biomedical Sciences Institute
Metastasis of 4T1 cells is very fast in mice, so we began treatment earlier in order to approximate what happens in humans.— Otávio Cabral Marques
La Conversación del Hearth Otra perspectiva de la historia
Why would a drug for lung disease work against cancer spread?
The drug blocks a receptor called endothelin type A, which exists on blood vessel linings and immune cells. It turns out this same receptor helps tumors migrate and build the blood supply they need. By blocking it, you're hitting two problems at once.
So it's not specifically designed for cancer?
Not at all. It was developed for pulmonary hypertension, which is a completely different disease. This is what researchers call drug repurposing—finding new uses for existing medications. The advantage is we already know it's safe enough for humans to take.
The 47 percent reduction in metastasis sounds impressive. Is that enough to change how we treat cancer?
It's promising, but it's mice, not people. The real question is whether that benefit holds up in actual cancer patients. That's what the clinical trials will answer. And even if it works, it might not work for all cancers equally.
Why test it alongside chemotherapy rather than alone?
Because chemotherapy is already the standard treatment. You want to know if adding this drug makes patients do better than chemotherapy alone. That's how you prove it actually helps.
What about applying it directly to the tumor instead of taking it by mouth?
That's still experimental thinking. Direct application might concentrate the drug where it's needed most, potentially making it more effective. But that adds complexity—you'd need a way to deliver it safely to the tumor site.
How long until we know if this actually works in people?
Clinical trials take years. We're probably looking at several years before there's solid evidence one way or another. The researchers are being appropriately cautious.