AbClon, Inc.

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. 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.

SEOUL, South Korea, April 17, 2023 /PRNewswire/ -- AbClon, a South Korean biotech firm, presented non-clinical and phase 1 interim results of its AT101 novel CAR-T therapy at the annual 2023 AACR conference. AT101 targets the CD19 protein for treatment of blood cancer. AT101 demonstrated superior anti-cancer efficacy compared to FMC63-based CAR-T therapies in non-clinical data. AT101 utilizes the h1218 antibody, developed through AbClon's Novel Epitope Screening Technology (NEST), and binds in a unique manner to CD19. AT101 demonstrated efficacy even in CD19 mutant cancer cell models that did not respond to FMC63-based CAR-T therapies. Overall, AT101 has the potential to provide new treatment opportunities for patients including those who do not respond to currently available CAR-T therapies. An open-label, non-randomized, multicenter phase 1 study was conducted at three different dose levels in patients with relapsed / refractory B-NHL. The results of the first two dose levels in Phase 1, low and medium, have been determined. For medium dose, although the dosage administered to patients is lower than that of currently available CAR-T therapies, all three patients achieved complete response (CR) four weeks after administration. Even at 5-fold lower dosage to medium dose, CR was observed in 3 out of 6 patients and partial response (PR) was observed in 2 patients. Cytokine release syndrome (CRS) and neurotoxicity (ICANS), which appear as side effects of CAR-T therapy, were also observed at low levels of 11.1% and 22.2%. In particular, the rate of 3 or higher grade on side effects was 11.1%, showing encouraging signs with regard to safety. Clinical trial of high dosage level is currently in progress. AT101 was administered to patients with diffuse large B cell lymphoma (DLBCL), follicular lymphoma (FL), mantle cell lymphoma (MCL), and marginal zone lymphoma (MZL). Effective responses to AT101 potentiate the application of AT101 for different types of hematologic malignancies. Research teams led by Professor Marco Ruella of Perelman School of Medicine at University of Pennsylvania, Professor Junho Chung of Seoul National University College of Medicine, and Professor Dok hyun Yoon of Asan Medical Center are participating in this study. AbClon owns independent intellectual property rights for the technologies applied to AT101 and is currently building channels for global expansion with local partners. AT101 patent registration has been completed in U.S., Canada, Japan, and South Korea. Further registrations are underway in Europe and China. Jong-Seo Lee, CEO of AbClon, said, "AT101 showed promising results in r/r B-NHL patients, including multiple CRs in the dose escalation stage and excellent safety. We are hopeful for ongoing trials of AT101 to provide more affordable and effective treatment opportunities to patients fighting blood cancer." For more information on the ongoing trial, refer to the ClinicalTrials.gov Identifier: NCT05338931 Details of the presentation are as follows: Presentation Title: An open label, dose escalation, phase 1 study of AT101, a novel CD19-directed CAR-T cell therapy targeting a membrane-proximal epitope of CD19, in patients with relapsed or refractory B cell non-Hodgkin lymphoma Session Title: Phase I Clinical Trials in Progress About AT101 AT101 is a CAR-T therapy that targets CD19 protein for blood cancer. AbClon has initiated a Phase 1/2 clinical study of AT101 in adults with relapsed or refractory B-cell non-Hodgkin lymphoma (NCT05338931) Phase 1/2 study is being conducted in Asan Medical Center and Ulsan University Hospital under the support of the Korea Drug Development Fund (KDDF) in Korea. About AbClon AbClon is a biopharmaceutical company with a robust, wholly owned R&D pipeline in oncology. It is headquartered in Seoul, South Korea. Further information about the company and its drug development programs and capabilities may be found online at Company Codes: Korea:174900