Precision immunotherapy
For B-cell driven autoimmune diseases where the autoantibody is known, researchers have begun to re-engineer T cells to recognize only autoreactive B cells. While CD19 CAR T cells act more like a sledgehammer, these precision cellular immunotherapies are “like a razor’s strike,” Dr. June said.
University of Pennsylvania
Dr. Aimee Payne
“The chimeric autoantibody receptor (CAAR) approach targets autoantibodies that are expressed only on the surface of autoimmune B cells and are not expressed on normal B cells, which ideally should lead to precision targeting of just the cells that cause autoimmune disease,” explained Aimee Payne, MD, PhD, professor of dermatology and director of the Penn Clinical Autoimmunity Center of Excellence at the University of Pennsylvania, Philadelphia.
She and her research team used this approach to develop a treatment for mucosal pemphigus vulgaris, an autoimmune blistering disease of mucous membranes driven by autoantibodies against desmoglein 3.
“The current standard of care for pemphigus is to treat with steroids and rituximab, an infusion therapy that results in global, but temporary, B-cell depletion,” she said. “By expressing desmoglein 3 (DSG3) on the surface of the CAAR T-cell therapy, we target just the anti-DSG3 B cells that cause disease in mucosal pemphigus vulgaris and spare the healthy B cells.”
The therapy – called DSG3-CAART – is being developed by Cabaletta Bio and is now in phase 1 clinical trials. The approach is also being investigated to treat certain types of myasthenia gravis and membranous nephropathy.
Dr. Konig’s lab at Johns Hopkins developed and is now exploring a new precision cellular immunotherapy approach, chimeric autoantigen-T cell receptor (CATCR) T-cell therapy, to treat antiphospholipid syndrome, which is in preclinical stages. In this approach, Dr. Konig and his team are “re-engineering the natural T-cell receptor to selectively kill disease-causing B cells that drive antiphospholipid syndrome,” he explained.
He anticipates the CD19 CAR T-cell therapies currently in clinical trials will help to pave the way for this new generation of precision cellular therapies. The ultimate goal of these therapies, he said, is to uncouple therapeutic potency from infection risk.
“That’s really the holy grail in the treatment of autoimmune diseases. It’s tantalizingly close, but we’re not there yet.”
Dr. June is an inventor on patents and/or patent applications licensed to Novartis Institutes of Biomedical Research and receives license revenue from such licenses. Dr. June is a scientific founder of Tmunity Therapeutics and Capstan Therapeutics and is a member of the scientific advisory boards of AC Immune SA, Alaunos, BlueSphere Bio, Cabaletta, Carisma, Cartography Biosciences, Cellares, Celldex, Decheng Capital, Poseida, Verismo, and WIRB-Copernicus Group. Dr. Konig is a consultant for argenx and Revel and is listed as inventor for patent applications filed by John Hopkins University. Dr. Payne holds equity, grants, payments, and patent licensing from Cabaletta Bio and consults for Janssen.
A version of this article first appeared on Medscape.com.