Obsidian Therapeutics to Present Preclinical Data from cytoTIL15™ Program at the American Associate of Cancer Research (AACR) Annual Meeting 2022

Data demonstrate significantly greater anti-tumor activity of cytoTIL15 therapy in vivo compared to conventional TIL + IL2 therapy

CAMBRIDGE, Mass., April 11, 2022 /PRNewswire/ -- Obsidian Therapeutics, Inc., a biotechnology company pioneering engineered cell and gene therapies, today announced it will present preclinical data highlighting its cytoTIL15™ program during a poster session at the upcoming AACR Annual Meeting 2022. The abstract title has been posted to the AACR Online Itinerary Planner, will be published in the online Proceedings of the AACR, and is detailed below.

The data to be presented demonstrate significantly greater anti-tumor activity of cytoTIL15 therapy in vivo compared to conventional TIL + IL2 therapy in a human leukocyte antigen (HLA)-matched, allogeneic patient-derived xenograft (PDX) melanoma model, including greater persistence of cytoTIL15 cells in blood and lymphoid organs, superior tumor growth inhibition including complete responses, and increased infiltration of tumors with cytoTIL15 cells.

"We look forward to presenting these new data at AACR, which continue to validate the exciting potential of our cytoTIL15 therapy to improve the treatment of patients with solid tumors," said Jan ter Meulen, M.D., Ph.D., Chief Scientific Officer at Obsidian Therapeutics. "We are encouraged by the data demonstrating superior anti-tumor activity of cytoTIL15 cells in the absence of IL2 in a novel PDX tumor model. These data deliver preclinical proof of concept for the potential of cytoTIL15 therapy as a treatment for metastatic melanoma and will support the planned filing of an IND for our lead  program, OBX-115, later this year."

Details of the poster presentation are as follows:

Abstract Number: 7994
Title: Allogeneic, IL-2-independent tumor-infiltrating lymphocytes expressing membrane-bound IL-15 (cytoTIL15™) eradicate tumors in a melanoma PDX model through recognition of shared tumor antigens
Presenter: Dr. Jeremy Tchaicha, Director, Head of In Vivo Pharmacology, Obsidian Therapeutics
Date and Time: Section 18, April 13, 2022, 9:00 a.m.-12:30 p.m. CT
Abstract Summary:  Current TIL therapy requires systemic administration of IL2 to promote TIL survival, and IL2-associated toxicities greatly limit patient eligibility and reduce the long-term clinical benefit of TIL therapy. Obsidian designed genetically engineered IL2-free TILs (cytoTIL15™) to express a regulated form of membrane-bound IL15 for tunable long-term persistence, leading to enhanced persistence and efficacy in vitro and in PDX tumor models. Obsidian previously demonstrated cytoTIL15 exhibited enhanced potency and persistence over conventional TILs in vitro, and persisted without IL2 at greater frequencies compared to conventional TILs + IL2 in a 10-day antigen-independent in vitro assay. Additionally, cytoTIL15 adoptively transferred into naïve NSG mice demonstrated long-term persistence without antigen or exogenous IL-2.

About OBX-115
OBX-115 is Obsidian's lead cytoTIL15 program, currently in preclinical development for the treatment of patients with metastatic melanoma and other solid tumors. OBX-115 is a novel engineered tumor infiltrating lymphocyte therapy armed with regulated membrane-bound IL15 that is designed to remove the need for concomitant IL2 therapy, a toxic and costly requirement for conventional TILs. The Company expects to submit an IND for OBX-115 in 2022. 

About Obsidian Therapeutics
Obsidian Therapeutics, Inc. is a biotechnology company pioneering engineered cell and gene therapies to deliver transformative outcomes for patients with intractable diseases. Obsidian's proprietary cytoDRiVE® technology provides a way to precisely control the timing and level of protein function by using FDA approved small molecules. Obsidian is headquartered in Cambridge, Mass. The Company has collaborations with Bristol Myers Squibb and Vertex Pharmaceuticals. For more information, please visit www.obsidiantx.com and follow us on LinkedIn and Twitter.

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SOURCE Obsidian Therapeutics