Potential New Mesothelioma Treatment: Using the Patient's own Immune System

In the August bulletin from the National Cancer Institute, researchers present results from a recent clinical trial that focused on patients who have mesothelioma or other forms of cancer that express the protein mesothelin and treatment using immunotherapy.

Immunotherapy is a relatively new form of cancer treatment that uses a patient’s own immune system to fight his or her illness. Researchers at the National Cancer Institute are working on a new form of immunotherapy known as adoptive cell transfer, or ACT.

When a patient is treated with ACT immunotherapy, his or her T cells (immune system cells) are collected then multiplied in a laboratory, growing the amount of immune cells that can fight infections or kill cancerous cells. Once the T cells are multiplied, they are returned to the patient.

Dr. Steven Rosenberg leads the team of NCI researchers, who are examining methods for genetically engineering T cells to recognize and adhere to a specific protein in a patient’s cancer cells. This protein, mesothelin, occurs in the tissues that line organs in the chest, abdomen, and other parts of the body (where mesothelioma strikes).

While mesothelin is present in healthy cells, larger amounts of this protein are found in cancerous cells in patients with some types of lung, esophageal, and ovarian cancers, as well as mesothelioma. Higher mesothelin levels in malignant cells is a marker for cancer and potentials find this an intriguing new target for immunotherapy. The NCI researchers are interested in trying this new approach in patients who have advanced cancer that has not responded well to more traditional treatments like chemotherapy and radiation.

In the trial, Dr. Rosenberg and his team collect T cells from patients who have advanced cancer that expressed mesothelin. The researchers then block the mesothelin by modifying immune cells to recognize the protein and bond to it, hoping that this approach will shrink tumors.

In preparation for immunotherapy, patients are given chemotherapy and must remain in the hospital for at least two weeks so that they can be monitored with frequent blood tests and imaging scans.

The study will continue through 2018, and Dr. Rosenberg and his team are currently seeking new patients. For more information on this new immunotherapy clinical trial, visit ClinicalTrials.gov.