For years, the foundations of cancer treatment have been surgery, chemotherapy, and radiation therapy. In the last two decades, drugs that target cancer cells have also become standard treatments for many cancers. These drugs work by homing in on specific molecular changes seen primarily in those cells. Most recently, over just the past several years, Immunotherapies—therapies that enlist and strengthen the power of a patient’s immune system to attack tumors—has emerged as what many in the cancer community now call the “fifth pillar” of cancer treatment.
At the Perelman School of Medicine at the University of Pennsylvania, Carl H. June, M.D., is director of Translational Research at the Abramson Cancer Center. As a specialist in T cell biology and lymphocyte activation, his groundbreaking work has led to remarkable remissions of advanced cancer. He focused on recent and ongoing successes in developing treatments with T cells that have been genetically engineered to target cancer. Called Chimeric Antigen Receptor T cells (CAR T cells), these modified immune cells have proven effective at eliminating cancer in some patients, and offer great hope for this emerging strategy in cancer immunotherapy.
New CAR T-cell Therapy – An immunotherapy approach called Adoptive Cell Transfer (ACT) is rapidly emerging. It involves collecting and using a patients’ own immune cells to treat their cancer. There are several types of ACT but the one that is closest to producing a treatment approved by the Food and Drug Administration (FDA) is called CAR T-cell therapy. One CAR T-cell therapy was approved in August 2017 by the FDA for the treatment of children with acute lymphoblastic leukemia (ALL). (www.cancer.gov).
A second, for adults with advanced lymphomas, may be close behind. In the study, 63 patients received a single dose. The overall remission rate was 82.5% in treated subjects. Forty patients (63%) had complete remission and 12 patients (19%) had complete remission with incomplete hematologic recovery. Researchers caution that, in many respects, it’s the very early days for CAR T cells and other forms of ACT, and there are questions about whether they will ever be effective against solid tumors like breast and colorectal cancer.
A Possible Option Where None Had Existed
The initial development of CAR T-cell therapies has focused largely on Acute Lymphoblastic Leukemia (ALL) the most common cancer in children. More than 80% of children diagnosed with ALL that arises in B cells—the predominant type of pediatric ALL—will be cured by intensive chemotherapy. But for patients whose cancers return after chemotherapy or a stem cell transplant, the treatment options are “close to none,” said Stephan Grupp, M.D., Ph.D., of the Children’s Hospital of Philadelphia (CHOP). Relapsed ALL, in fact, is a leading cause of death from childhood cancer.
Dr. Grupp has led several trials of CAR T cells in children and young adults with ALL that had recurred or was not responding to existing therapies. In one of these earlier trials, which used CD19-targeted CAR T cells, all signs of cancer disappeared (a complete response) in 27 of the 30 patients treated in the study, with many of these patients continuing to show no signs of recurrence long after the treatment.
ALL Research is also underway at Shands Children’s Hospital at the University of Florida in Gainesville, where William “Dr. Bill” Slayton joined the division in 2002 with a focus on platelet disorders and leukemia. Now the chief of the division of Pediatric Hematology / Oncology, he also chairs the Children’s Oncology Group clinical trial AALL0622, His laboratory has interest in how normal and leukemic stem cells interact with the bone marrow microenvironment. Current projects are focused on developing better therapies for Ph+ ALL and Infant Leukemia.
The Cancer Research Institute has a webinar series, “Cancer Immunotherapy and You,” offered free to the public for patients and caregivers from leaders in cancer immunotherapy, followed by a Q&A. Visit www.cancerresearch.org/webinars.
Story by STEVE TRAIMAN
[Steve Traiman is President of Creative Copy by Steve Traiman in St. Pete Beach, offering freelance business writing services. He can be reached via email at traimancreativecopy@gmail.com]