A groundbreaking study has shown that a drug currently being tested for ovarian and bile duct cancer, called NXP800, could also help treat advanced prostate cancer that no longer responds to hormone therapy.
Published in Clinical Cancer Research, the study highlights how NXP800 slows the growth of prostate cancer cells, even in cases resistant to standard hormone treatments like enzalutamide.
Prostate cancer is one of the most common cancers in men, and advanced cases are often treated with hormone therapies such as enzalutamide and abiraterone.
These drugs work by blocking androgen hormones that fuel the growth of prostate cancer cells.
While effective for many patients, these treatments eventually stop working as the cancer becomes resistant, leaving patients with few options.
To address this, researchers at The Institute of Cancer Research (ICR) in London turned their attention to a new approach. They focused on a pathway in cells known as Heat Shock Factor 1 (HSF1), often described as a “master switch.”
This pathway helps cancer cells survive under stress by producing heat shock proteins, which protect them from damage. Unfortunately, higher levels of these proteins have been linked to faster-growing, harder-to-treat prostate cancers and worse outcomes for patients.
NXP800, discovered at the ICR, targets the HSF1 pathway. By disrupting this “master switch,” the drug reduces the production of heat shock proteins, making cancer cells more vulnerable.
Laboratory tests showed that NXP800 was effective at slowing the growth of prostate cancer cells, even when hormone therapy no longer worked. In models using advanced prostate cancer cells grown as mini-tumors, the drug had a much stronger effect than enzalutamide at stopping tumor growth.
In experiments with mice, NXP800 showed even more striking results. In untreated mice, all tumors doubled in size within 38 days.
But when treated with NXP800, only about 37% of tumors reached that size in the same timeframe. These findings demonstrate the drug’s potential to significantly slow the progression of hormone-resistant prostate cancer.
The study also uncovered how NXP800 works on a molecular level. By blocking HSF1 activity, the drug interferes with the unfolded protein response, a system that helps cells cope with stress.
This disruption affects other key proteins that control gene activity in prostate cancer cells, making the disease more vulnerable to treatment. Understanding these mechanisms is crucial for identifying which patients are most likely to benefit from the drug in future clinical trials.
NXP800 is already being tested for ovarian and bile duct cancers, with the U.S. Food and Drug Administration (FDA) granting it special designations to speed up its development.
Until now, its potential for treating prostate cancer had not been explored. The new findings could pave the way for clinical trials to test the drug’s effectiveness in men with advanced prostate cancer.
Dr. Adam Sharp, who co-led the study, emphasized the need for new approaches to tackle drug resistance. “Targeting the heat shock response pathway offers a fresh angle for treating advanced prostate cancer,” he said.
His colleague, Professor Johann de Bono, noted that patients with higher levels of heat shock proteins face worse outcomes, making this pathway an important target for new treatments.
The researchers hope these findings will lead to clinical trials that could offer new hope to men whose cancer no longer responds to hormone therapy. If successful, the drug could extend survival and improve quality of life for patients with few remaining options.
Simon Grieveson of Prostate Cancer UK called the study a “fantastic example” of innovative research addressing treatment resistance. He highlighted the importance of finding solutions for men with advanced prostate cancer to give them more time with their families.
This breakthrough represents a significant step toward overcoming one of the biggest challenges in cancer treatment: drug resistance. While more research is needed, the potential of NXP800 offers hope for improving outcomes and quality of life for patients with advanced prostate cancer.
If you care about prostate cancer, please read studies about 5 types of bacteria linked to aggressive prostate cancer, and new strategy to treat advanced prostate cancer.
For more information about prostate cancer, please see recent studies about new way to lower risk of prostate cancer spread, and results showing three-drug combo boosts survival in metastatic prostate cancer.
The research findings can be found in Clinical Cancer Research.
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