Researchers have developed a new treatment that blocks a protective enzyme in cancer cells, showing promise in early clinical trials for patients with mesothelioma.
Key facts
- •Mesothelioma affects approximately 30,000 people worldwide annually and has a five-year survival rate of about 10 percent.
- •The experimental drug RSO-021 is delivered locally into the chest to treat pleural effusions, which occur in about 90 percent of mesothelioma patients.
- •Laboratory studies showed that deleting PRX3 in mice did not produce adverse effects, suggesting the target is safe to inhibit.
- •The phase one clinical trial for RSO-021 was conducted between 2022 and 2023 under the oversight of the UK's MHRA.
- •Researchers are now exploring the use of thiostrepton-based treatments for other cancers, including peritoneal and gastric malignancies.
A research team led by the University of Vermont has developed an experimental drug, RSO-021, that targets the antioxidant defenses of mesothelioma cells. In a phase one clinical trial, the treatment controlled disease progression in 67% of participants. The drug works by disabling the enzyme peroxiredoxin 3 (PRX3), causing oxidative damage that leads to tumor cell death.
By the numbers
Mechanism and Clinical Results
Mesothelioma cells rely on high levels of PRX3 to neutralize reactive oxygen species generated by their active metabolisms. By using a derivative of the antibiotic thiostrepton to block this enzyme, the drug causes hydrogen peroxide to accumulate within the tumor's mitochondria. This approach is designed to be selective, as cancer cells produce more reactive oxygen species than healthy tissue. In the phase one trial conducted in the United Kingdom, 15 patients received the treatment directly into the chest via catheter. The study met its safety goals, and researchers observed that patients lived longer than those typically seen with standard therapies, despite a progression-free survival rate of 4.2 months.
Future Development and Research
The treatment was developed by RS Oncology, a company established to advance discoveries made at the University of Vermont. Beyond its direct ability to kill tumor cells, researchers believe the drug may also modulate the immune system to help it restrain cancer growth. Phase two of the clinical trial has been completed, with results expected to be presented at a global oncology meeting this year. Scientists are currently working on second-generation inhibitors with improved solubility, which could eventually allow for oral administration. Researchers are also investigating the potential application of this mechanism to other cancers, including gastric and gastrointestinal malignancies.
Advertisement
This article was independently rewritten by ManyPress editorial AI from reporting originally published by ScienceDaily.
