Immunotherapy Update: Recent Advances in CAR T-cell Therapy
As a measure of its promise, chimeric antigen receptor (CAR) T-cell therapy – where patients’ own immune cells are collected, genetically changed and used to treat their cancer – is the American Society of Clinical Oncology (ASCO) Advance of the Year for 2018.[i] This approach represents an exciting innovation that has the potential to transform cancer care.[ii] CAR T-cell therapy is clinically the most advanced of the adoptive cell transfer (ACT) class of immunotherapies, and has primarily been used in patients with advanced blood cancers.[iii] Imaging analytics – with its ability to guide treatment, evaluate response to therapy and assess likelihood of disease recurrence – holds promise in further advancing this important area.
CAR T-cells are custom made to work against the cancer in each individual patient, explains ASCO. “To create these cells, researchers collect immune T cells from the patient and insert an artificial gene…The gene is designed to endow T-cells with chimeric antigen receptors that can detect unique molecules on cancer cells after CAR T-cells are multiplied in the laboratory and injected back into the patient. In essence, CAR T-cell therapy is both a gene therapy and an immunotherapy.”[iv]
Following several decades of research, progress with CAR T-cells is accelerating and translating into improvements in clinical care. In 2017, the U.S. Food and Drug Administration approved 46 novel drugs,[v] including two CAR T-cell therapies, tisagenlecleucel (for B-cell precursor acute lymphoblastic leukemia that is refractory or in second or later relapse)[vi] and axicabtagene ciloleucel (for relapsed or refractory large B-cell lymphoma).[vii] These therapies are poised to transform treatment of childhood acute lymphoblastic leukemia and hard-to-treat lymphoma in adults, according to ASCO.4 An estimated 240 CAR T clinical trials are currently underway,[viii] and further substantial progress is expected in the next few years.[ix]
The market for CAR T-cell therapies is growing rapidly, with a value estimated at $72.0 million in 2017, and a forecast compound annual growth rate (CAGR) of 46.1 percent during 2019-28.[x] Overall, the worldwide market for immunotherapy drugs is predicted to reach $201.52 billion by 2021 from $108.41 billion in 2016, growing at a CAGR of 13.5 percent.[xi]
Looking ahead, imaging analytics will have a key role in clinical trials for CAR T-cell therapies, building our understanding of novel response patterns, enabling accurate interpretation of patient responses, and identifying appropriate therapy length. Coupled with use of appropriate criteria to assess response patterns, these factors will all help improve patient outcomes.
Immunotherapy: “A type of therapy that uses substances to stimulate or suppress the immune system to help the body fight cancer, infection, and other diseases.”
Adoptive cellular therapy: “A treatment used to help the immune system fight diseases, such as cancer and infections with certain viruses. T cells are collected from a patient and grown in the laboratory. This increases the number of T cells that are able to kill cancer cells or fight infections. These T cells are given back to the patient to help the immune system fight disease. Also called cellular adoptive immunotherapy.”
Chimeric antigen receptor (CAR) T cell therapy: A type of treatment in which a patient’s T cells (a type of immune system cell) are changed in the laboratory so they will attack cancer cells. T cells are taken from a patient’s blood. Then the gene for a special receptor that binds to a certain protein on the patient’s cancer cells is added in the laboratory. The special receptor is called a chimeric antigen receptor (CAR). Large numbers of the CAR T cells are grown in the laboratory and given to the patient by infusion.
CAR T-Cell Immunotherapy: The 2018 Advance of the Year1
Post Authored By:
Yan Liu, MD, Medical Director, Median Technologies