Breakthrough in Cancer Treatment: Bulgarian Scientist Stops Tumor Growth and Metastasis

A Bulgarian scientist has developed a drug that halts the growth of cancer and prevents metastases from spreading to other organs. Assoc. Prof. Dr. Zdravka Medarova, a leading figure in modern RNA-based medicine, has been at the forefront of this research. Her drug is designed to specifically target tumor cells and their scattered counterparts throughout the body, offering a new approach to combatting the disease. Preclinical studies in animals have shown promising results, and the treatment has already been administered to 16 patients.

Dr. Medarova, who is the scientific director of TransCode Therapeutics, explained that while the drug does not yet shrink tumors, it successfully stops them from growing. In 44% of treated patients, cancer progression has been halted for seven months or longer. Some patients continue treatment, with one individual maintaining tumor stability for 13 months. The goal of the therapy is to prevent cancer spread, allowing traditional treatments like surgery or radiation to be more effective. “Invisible cancer cells are scattered throughout the body, and we cannot remove them surgically or target them all with radiation, but this drug addresses them,” Medarova said.

Her journey in RNA oncology began years ago during a university lecture on genetics and research with roundworms, which easily absorb double-stranded RNA. This led to the concept of using RNA to silence malfunctioning genes responsible for cancer. Over time, her team developed nanoparticles capable of reaching tumor cells, carrying RNA molecules that disable harmful gene activity. This breakthrough propelled Medarova and her team to prominence in RNA medicine.

She recounted a pivotal moment in the lab: mice treated with her RNA-based drug remained healthy, active, and free of tumors, while those given a control treatment suffered severe illness and widespread tumors. These early experiments confirmed the potential of her approach.

The clinical trial is now entering its second phase, testing four different dosages to determine patient safety. So far, the drug has shown no toxicity. Currently, the treatment targets 20% of known cancer-causing genes, but RNA-based therapy could eventually address the remaining 80%, offering a way to “turn genes on and off like a piano” and treat cancer more precisely. The second phase of trials is expected to continue until 2028, with potential FDA approval or phase three trials to follow. Medarova estimates that, if successful, the treatment could be available to patients around 2031-2032.

Despite the cautious timeline, Dr. Medarova remains motivated by personal experience: her father died of cancer, inspiring her mission to prevent others from facing the same fate.

Zdravka Medarova’s credentials are extensive. She holds a PhD in genetics from the University of New Hampshire and specialized at a leading hospital in Massachusetts. An associate professor at Harvard Medical School, she has earned numerous international awards and is recognized for her contributions in the U.S., Japan, and globally. Her scientific achievements mark her as one of the leading experts in RNA medicine today.