ImmunoMRI for Assessment of Tumor-associated Macrophages: A Prospective Study in Patients With Diffuse Large B-cell Lymphoma Receiving CAR T-cell or Bispecific Antibody Therapy

Lymphomas are the most common types of blood cancer worldwide. Among these, diffuse large B-cell lymphoma (DLBCL) is both the most common overall and the most aggressive type, affecting about 4 out of every 100,000 people in Europe each year. This cancer typically causes noticeable symptoms and requires immediate treatment.

The World Health Organization recognizes several subtypes of DLBCL based on how the cancer cells look under a microscope, clinical features, and genetic characteristics. Some variants are particularly aggressive, especially those with multiple genetic abnormalities called "double-hit" or "triple-hit" lymphomas.

While many patients with DLBCL can be cured with intensive combination treatments that include both chemotherapy and immunotherapy, about 30-40% of patients experience cancer that comes back or does not respond to treatment. For these patients, traditional intensive treatments followed by stem cell transplants offer poor outcomes, with patients typically surviving only about 6 months. This urgent need has led researchers to develop new, more targeted therapeutic approaches, such as CAR T-cells and bispecific antibodies.

CAR T-Cell Therapy:

Reprogramming the Body's Own Defense System CAR T-cell therapy represents a groundbreaking approach to cancer treatment. This innovative treatment works by taking a patient's own immune cells (called T-cells) from their blood and genetically modifying them in a laboratory. These modified cells are programmed to specifically recognize and attack cancer cells. The process involves adding special receptors to the T-cells that can identify specific proteins on cancer cells, particularly one called CD19 that's commonly found on lymphoma cells. Once these engineered T-cells are infused back into the patient, they multiply and launch a targeted attack against the cancer. Currently, three CAR T-cell products are approved for clinical use, each with slightly different characteristics and side effect profiles. Major clinical trials have shown remarkable results, with complete remission rates of 65-66% compared to only 32-39% with standard treatments. Patients also experienced much longer periods without cancer progression. However, CAR T-cell therapy comes with significant challenges. The treatment can cause serious side effects in the majority of patients, including potentially life-threatening conditions called cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). Additionally, the treatment isn't immediately available because it requires collecting the patient's cells, modifying them in specialized facilities, and then manufacturing the personalized treatment-a process that can cause dangerous delays.