OBX-115

The recent U.S. FDA approval of lifileucel, a non-engineered, autologous tumor-infiltrating lymphocyte (TIL) therapy, for unresectable or metastatic melanoma represents a major milestone for cellular therapies in solid tumors...OBX-115, designed with regulatable membrane-bound IL-15 expression, eliminates the need for IL-2 infusion and has shown early clinical activity. KSQ-001EX uses CRISPR/Cas9 to inactivate SOCS1, while KSQ-004EX additionally targets Regnase-1 to enhance TIL function...TIL therapy remains among the most promising strategies in melanoma and solid tumors after immunotherapy failure. Ongoing research aims to optimize cell dose, phenotype, tumor procurement, treatment sequencing, and rational combinations to improve durable benefit.

P1/2, N=208, Recruiting, Obsidian Therapeutics, Inc. | N=52 --> 208

Here, we report the successful generation and expansion of TIL engineered with regulatable, membrane-bound IL15 (cytoTIL15™ cells) from immune-excluded, paucicellular chondrosarcoma biopsies largely consisting of collagenous matrix and demonstrate that these cells have potent tumor-killing capacity in cell culture and in tumor spheroid models in the absence of exogenous IL2...Moreover, we demonstrate that IL15 reduced the signaling threshold of T-cell receptors isolated from TIL clonotypes, increasing their infiltration and cytotoxicity in autologous 3D tumor models. These results suggest the possibility of developing an effective IL2-free TIL therapy for patients with immune-excluded tumors.

P1/2, N=52, Recruiting, Obsidian Therapeutics, Inc. | Trial completion date: Oct 2027 --> Jun 2028 | Trial primary completion date: Oct 2025 --> Jun 2028

cytoTIL15™ cells express mbIL15 fused to a drug-responsive domain (DRD) that is regulated by the FDA-approved small-molecule drug acetazolamide (ACZ). In patient-derived xenograft (PDX) tumors, spatial profiling revealed infiltrating cytoTIL15 cells to be highly cytotoxic and less exhausted than non-engineered TIL. This novel platform creates a powerful, IL2-free TIL cell therapy with a potentially improved tolerability and safety profile, while allowing individualized pharmacologic regulation of the TIL product.

P1, N=21, Active, not recruiting, M.D. Anderson Cancer Center | N=30 --> 21 | Recruiting --> Active, not recruiting

P1/2, N=52, Recruiting, Obsidian Therapeutics, Inc. | N=32 --> 52

P1/2, N=32, Recruiting, Obsidian Therapeutics, Inc. | Active, not recruiting --> Recruiting

P1/2, N=32, Active, not recruiting, Obsidian Therapeutics, Inc.

We previously showed that melanoma TILs engineered to express membrane-bound IL15 (mbIL15) under the control of the ligand acetazolamide (ACZ) can achieve IL2-independent expansion during manufacturing, antigen-independent persistence in vitro and anti-tumor efficacy in vivo. Unlike unengineered TILs, cytoTIL15 cells + ACZ persisted in an antigen-free setting without IL2, were cytotoxic to autologous PDc and released IFNγ in response to autologous PDx tumor digest. Taken together, these data show that IL2-independent, fully functional cytoTIL15 cells can successfully be generated from tumors such as NSCLC, HNSCC & TNBC, which afflict large numbers of patients.

Cytokines modified with our carbonic anhydrase 2 (CA2)-based cytoDRiVE® drug responsive domain (DRD) were evaluated for control of protein levels with the CA2 ligand, acetazolamide (ACZ). Conclusions While IL-15 drives expansion and persistence of cytoTIL15 TM cells without IL-2, adding pleotropic and highly immune-stimulatory members of the IFN, IL-1 or TNF families may provide enhanced efficacy for patients with solid tumors marked by an immunosuppressive TME. Ethics Approval All animal studies were IACUC approved

Methods cytoTIL15® therapy contains TILs engineered with mbIL15 under the control of a carbonic-anhydrase-2 drug responsive domain, regulated by the ligand acetazolamide (ACZ). Interestingly, the subpopulation of cytoTIL15® cells reactive to tumor-associated antigen MART-1 displayed increased expression of TCF-1, which in melanoma patients has been associated with responses to immune checkpoint blockade, in addition to progression-free and overall survival. Ethics Approval All animal studies were IACUC approved.