First-in-human clinical trial of CAR T cell therapy with new binding mechanism shows promising early responses

Newswise — SAN DIEGO – Early results from a Phase I clinical trial of AT101, a new CAR T cell therapy that uses a distinct binding mechanism to target CD19, show a 100 percent complete response (CR) rate at the higher dose levels studied in the trial, according to researchers from the University of Pennsylvania Perelman School of Medicine and Penn Medicine’s Abramson Cancer Center. The findings were published today in Molecular Cancer and presented at the 65th American Society of Hematology (ASH) Annual Meeting and Exposition (Abstract 2096).

CAR T cell therapy has revolutionized treatment for many people with blood cancers who had run out of other treatment options. While some patients experience long-term responses to CAR T cell therapy, it doesn’t work–or the cancer eventually returns–for others. The CD19 CAR T cell therapies that are currently approved all target CD19 through the same epitope (FMC63). To try and make CD19 CAR T cell therapy more effective for more patients, Marco Ruella, MD, an assistant professor of Hematology-Oncology and Scientific Director of the Lymphoma Program, and his research team, along with the Korean company AbClon Inc, co-developed a CAR T product (AT101), using cells originating from the same patient, that targets CD19 through a different epitope, located closer to the cell membrane, via a novel antibody (h1218). In preclinical studies, the team previously demonstrated that h1218-CART19 had decreased T cell exhaustion and improved control compared to FMC63-CART19.

The Phase I first-in-human clinical trial (NCT05338931) was conducted in South Korea and enrolled 12 patients with relapsed or refractory B cell non-Hodgkin’s lymphoma (NHL). The study was designed to increase the dose level of AT101 after safety was confirmed in the first six patients. After a median follow-up of 6.5 months, all six patients who received dose level 2 or higher experienced a complete response and their cancer has not relapsed.  

“We’ve learned that the way you design your CAR really matters. Designing a different CAR might drastically change the way the T cells work, potentially allowing that CAR T cell product to work where other CAR T cell products have failed,” Ruella said. “We were not expecting such a drastic early difference in this study. The CART19 products that are already FDA-approved are very effective, and it’s not easy to do better. While there is not a randomized trial of this product yet, the initial results seem very promising, and we look forward to moving into the planned Phase II portion of the study.”

The drug was found to be safe, with manageable side effects, including cytokine-release syndrome in four patients and immune-cell-related neurotoxicity syndrome in three patients. One patient experienced grade 3 sepsis that resolved; the same patient later developed fatal neutropenic septic shock outside the dose-limiting toxicity time frame.

The Phase I study enrolled patients who had not previously received any other CAR19 therapy. In the Phase II expansion, the study will also include patients who have previously received CAR19 therapy.

Editor’s Note: The study was funded by AbClon Inc; Ruella is a paid consultant for the company and has a Sponsored Research Agreement with them.

Yunlin Zhang, MS, a research specialist in Ruella’s lab, will present the findings in a poster session on Saturday, Dec. 9, from 5:30 to 7:30 p.m. PT in the San Diego Convention Center Halls G-H.

###

Penn Medicine is one of the world’s leading academic medical centers, dedicated to the related missions of medical education, biomedical research, excellence in patient care, and community service. The organization consists of the University of Pennsylvania Health System and Penn’s Raymond and Ruth Perelman School of Medicine, founded in 1765 as the nation’s first medical school.

The Perelman School of Medicine is consistently among the nation’s top recipients of funding from the National Institutes of Health, with $550 million awarded in the 2022 fiscal year. Home to a proud history of “firsts” in medicine, Penn Medicine teams have pioneered discoveries and innovations that have shaped modern medicine, including recent breakthroughs such as CAR T cell therapy for cancer and the mRNA technology used in COVID-19 vaccines.

The University of Pennsylvania Health System’s patient care facilities stretch from the Susquehanna River in Pennsylvania to the New Jersey shore. These include the Hospital of the University of Pennsylvania, Penn Presbyterian Medical Center, Chester County Hospital, Lancaster General Health, Penn Medicine Princeton Health, and Pennsylvania Hospital—the nation’s first hospital, founded in 1751. Additional facilities and enterprises include Good Shepherd Penn Partners, Penn Medicine at Home, Lancaster Behavioral Health Hospital, and Princeton House Behavioral Health, among others.

Penn Medicine is an $11.1 billion enterprise powered by more than 49,000 talented faculty and staff.