CAR-T therapy is effective against ovarian cancer under study – 02/06/2023 – Equilibrium and Health

New research has shown that CAR-T cell therapy was effective against ovarian cancer in mice, a previously unattainable feat for solid tumor cancer treatments.

According to the study, in some of the mice studied there were no longer any detectable cancer cells, which made scientists believe that the therapy was effective in definitively treating the disease.

Despite these being results obtained in laboratory animals, the researchers are confident that the therapy can have similar effects in women with ovarian cancer.

The research, published on Monday (6) in the specialized journal Journal for ImmunoTherapy of Cancer, was developed by scientists at the Karolinska Institute, in Stockholm (Sweden).

CAR-T cells are immune system cells (known as T lymphocytes) taken from the patient and genetically modified to recognize and attack tumor cells. They are then reintroduced into the patient and become more effective in identifying the cancerous focus and attacking it.

CAR-T therapy has been successful in treating some types of cancer of the blood system, lymphomas and leukemias, but there is no proven efficacy against solid tumors. In these cases, chemotherapy, radiotherapy or treatments such as immunotherapy tend to be more effective.

In the case of ovarian cancer, some tumors have an associated protein called mesothelin. The Karolinska Institute researchers then used three different types of modified CAR-T cells to detect this compound.

In tests conducted in test tubes in the laboratory, the three types of cells showed results against cancerous tumor cells. After reintroduction into mice, 1 of the 3 types was highly effective over the others, with a significant reduction in tumor size and increased survival. And some were cured of tumor cells.

“In many mice, there were no longer detectable tumor cells, and the therapy effect continued even three months after starting treatment. This is clear evidence of how effective CAR-T cell immunotherapy was in attacking cells expressing the ovarian tumor mesothelin”, said Jonas Mattsson, one of the research coordinators and a professor in the Department of Oncology and Pathology at the institute.

Isabelle Magalhães, who is also one of the coordinators of the study and an associate professor at the same department, says she believes that the results bring hope for the treatment of this type of cancer with the highest mortality rate: about 70% of women. diagnosed with ovarian cancer die within five years of diagnosis.

“Despite many advances in cancer treatment in recent years, the prognosis for most women with ovarian cancer remains poor,” he said.

One of the problems with ovarian cancer is precisely its detection, since it is generally asymptomatic, especially considering older women. If done in the initial phase, the chance of healing is 80% to 90%.

The most commonly used treatment is surgery combined with radiotherapy or chemotherapy, which can begin even before surgery. Other types of treatments will also depend on the stage of the disease and whether it has spread to other parts of the body.

In Brazil, according to data from Inca (National Cancer Institute), around 6,000 new cases of ovarian cancer are diagnosed each year.

The expectation of the scientists at the Karolinska Institute is now to open possibilities for clinical trials with the treatment. “Our goal is to be able to create the ideal conditions for CAR-T cells that manage to infiltrate and attack the tumor and survive in the body of women with ovarian cancer”, says Mattsson.

The research was financially supported by the Swedish Cancer Society, the Swedish Foundation for Childhood Cancer, the Radium Hemmet Cancer Research Fund and received donations from the couple of millionaires and Swedish entrepreneurs Jeanette and Harald Mix.