A phase I study was recently presented at the American Association of Clinical Research Annual Meeting. The results of the study revealed that CAR (chimeric antigen receptor) T-cells that were targeting mesothelin served to be active for the patients having the malignant pleural disease due to mesothelioma or other types of solid tumors.
The CAR T-cells Success
The researchers in the given study made use of the 2nd generation CAR of CD28-costimulated mesothelin type with the safety gene “Icaspase-9” (IcasM28z). The given study was conducted on as many as 21 patients having malignant pleural disease proven by biopsy. The given case of the patients also expressed mesothelin with 19 patients having malignant pleural disease, one of them with lung cancer, and the remaining one patient with breast cancer. The patients were given IcasM28z single dosage CAR T-cells intrapleurally –cyclophosphamide preconditioning in some cases. It was carried out through either an interventional radiology or pleural catheter procedure. Around 18 patients received cyclophosphamide pre-conditioning. 12 patients were subject to CAR T-cells by making use of the interventional radiology technique.
Response of the Treatment
After the treatment, one patient has successfully undergone surgical resection with the curative intent three weeks after the infusion of the CAR T-cells. Persistence of CAR T-cells was reported in 13 patients. In the given patients, the persistence of the CAR T-cells occurred from the period of day 2 to around 42 weeks. Persistence of the T-cells was also associated with a decrease in the overall levels of mesothelin-related peptide that was soluble in serum. The given treatment reported an overall response rate of around 72 percent when it was blended with the immune checkpoint blockade.
Among 19 patients having malignant pleural mesothelioma, two patients experienced a complete metabolic response during the positron emission tomography scan. At the same time, 5 patients were successful in receiving partial response, and four of them had stable disease. The given treatment of solid tumors with the help of CAR T-cells infusion can serve to be a breakthrough in the medical science.