T-Cell Immunotherapy Trial Could be Good News for Mesothelioma Patients

The first four mesothelioma patients treated with a new kind of T-cell immunotherapy have responded well with few side effects. 

That is the word from researchers working with the drug TC-210. TC-210 is a type of T cell therapy. It is made by TCR² Therapeutics.

Malignant mesothelioma is one of several kinds of cancers that overproduce the protein mesothelin. In the Phase I trial, tumors regressed in all five cancer patients who received T-cell immunotherapy with TC-210. 

Targeting Cancer with T-Cells

T-cells are immune system cells that help fight cancer and other invaders. Mesothelioma and other cancers have ways of avoiding the body’s natural killer T-cell response. T-cell immunotherapy helps to turn it back on. 

TC-210 is like a “living drug” for malignant mesothelioma. Scientists start with T-cells extracted from the patient’s blood. The cells are altered to recognize certain antigens on the surface of cancer cells. 

In the case of mesothelioma, the targeted antigen is mesothelin. Mesothelin appears to help drive tumor growth and spread. People with high levels of mesothelin stand to benefit the most from T-cell immunotherapy. 

Testing T-Cell Immunotherapy with TC-210

TC-210 is one of several TRuC-T therapies from TCR² Therapeutics. TRuC-T cells are different from other types of T-cell immunotherapy, including CAR-T cells. Scientists at TCR² Therapeutics say TRuC-T cancer therapies seem to work better than CAR-T cell treatments with fewer complications.

The Phase I trial of TC-210 included four mesothelioma patients and one ovarian cancer patient. The patients had been through many different treatments but their cancers kept growing. 

The goal of the Phase I trial of this T-cell immunotherapy was to test its safety and decide on the best dose for a larger, Phase II trial. 

Results of the TC-210 Phase I Trial

All five patients experienced tumor regression (a decrease in tumor size). Two patients had a partial response (at least 50 percent reduction in tumor size). Two patients had stable disease (no tumor growth) for six months. 

“We are delighted that our very first dose of TC-210 induced consistent tumor regression and clinical benefit in heavily pre-treated cancer patients,” said Garry Menzel, PhD, President and CEO of TCR² Therapeutics. “There are very few options for patients with solid tumors and those expressing mesothelin represent a significant frontier of unmet medical need.”

The next step is a Phase II trial of this T-cell immunotherapy. Enrollment is open to patients with advanced mesothelioma and others with mesothelin-expressing tumors. More information on that trial can be found here. 

Most cases of mesothelioma come from asbestos exposure. The US is one of the few industrialized countries that does not ban asbestos. About 2,500 Americans get sick with malignant mesothelioma every year.

Sources:

TCR² Therapeutics Announces RECIST Responses with First TC-210 Dose Tested in Advanced Mesothelin-Expressing Solid Tumors”, July 26, 2020, News Release, TCR² Therapeutics website, https://investors.tcr2.com/news-releases/news-release-details/tcr2-therapeutics-announces-recist-responses-first-tc-210-dose