New "smart therapies" against cancer: they attack cells and slow ovarian tumor growth.

CRIS Against Cancer, a leading organization in research into this disease, is leading two innovative projects for the treatment of ovarian cancer based on "smart antibodies" that exclusively attack tumor cells, preserve the patient's healthy tissue, and block tumor growth.

The CRIS Against Cancer research group, led by Dr. Atanasio Pandiella Alonso , co-director of the CRIS Ovarian Cancer Project, located at the Cancer Research Center (CIC) in Salamanca, is developing cutting-edge therapeutic strategies: the so-called antibody drug conjugates or ADCs.

This technology combines antibodies —biological molecules capable of specifically recognizing tumor proteins—with the effectiveness of highly potent drugs. In other words, they are "guided missiles" that recognize tumor cells and deliver a highly potent therapeutic payload, destroying the tumor and minimizing damage to healthy tissue.

Ovarian cancer is one of the greatest challenges in current oncology. In most cases, it is diagnosed late, when the disease has already spread throughout the body and therapeutic options are more limited. Furthermore, relapse rates remain high because it is diagnosed late, and conventional treatments do not always succeed in controlling the progression of the disease.

In one of CRIS Against Cancer's most advanced projects, researchers have identified a protein present primarily in ovarian cancer cells and only rarely in healthy cells.

This discovery is important for preventing the drug-containing antibody , the ADC that acts against that protein, from damaging normal cells. Thanks to this discovery, researchers have developed a biological missile in the form of an ADC capable of effectively recognizing and destroying tumor cells. Tests in cellular models, using human ovarian cancer cells, and in animals have shown that tumors grow much less, even in metastatic cells obtained from real patients, which are much more aggressive.

Furthermore, it has proven safe and potent at low doses , which would facilitate its development as a new therapy. Currently, this disease has some targeted therapies, but this new ADC could be even more effective than some currently available treatments.

"The fact that the treatment can work even in metastatic cells is excellent news, because it is precisely disseminated disease that poses the greatest challenge in ovarian cancer," emphasizes Dr. Atanasio Pandiella , co-director of the CRIS Ovarian Cancer Project.

The other line of parallel research the researchers are working on is a second protein, also present in ovarian cancer. Using an antibody already known and approved for other types of tumors, they have developed a new treatment, also in the form of an ADC, that blocks the ability of tumor cells to divide and triggers their death.

This therapy has shown great efficacy in slowing tumor growth in experimental models, inducing cell death in less than 24 hours. This ADC interferes with the cell multiplication process, which is what tumor cells use to grow uncontrollably.

Both projects have not only shown very promising results in the laboratory, with cells from ovarian cancer patients obtained thanks to the collaboration between the CIC and the Hospital de Salamanca, but the team of scientists is already working on the development of their own antibody to advance towards future clinical trials and with a clear objective: that the results of this research reach the hospital and ovarian cancer patients as soon as possible.

Furthermore, researchers are exploring the possibility of using these antibodies as a prognostic tool, using blood samples—what we call liquid biopsy—to determine whether a person is responding to therapies.

If this strategy is confirmed, it would not only allow for more effective cancer treatment, but also for monitoring patients' response in a simple and less invasive manner, by studying this protein with a simple blood test.