Obsidian Presents Preclinical Data at ASGCT Showing Advancement of Its Regulated IL12 and IL15 Programs to Enable Safer and More Effective CAR-T Therapies

Therapeutics, Inc.
, a biotechnology company dedicated to the
development of next-generation
cell and gene therapies
with pharmacologic operating systems, today
announced that the company presented preclinical data on its regulated
IL12 and IL15 programs at the Annual Meeting of the American Society of
Gene and Cell Therapy in Chicago, IL.

Obsidian is developing CAR-T therapies that incorporate Destabilizing
Domains (DDs) to regulate expression of immune cytokines, thereby
providing pharmacologic control over these potent but potentially toxic
molecules. DDs are small, fully-human protein domains that confer
conditional stability to a fused payload protein that is engineered into
a cell or gene therapy product. IL12 and IL15 are two important immune
cytokines that play important roles in tumor response to adoptive cell
therapy but which require precise control to optimize their therapeutic

“IL12 and IL15 are critical factors that promote CAR-T cell expansion,
persistence, and penetration into solid tumors,” said Vipin Suri, Ph.D.,
Vice President of Discovery of Obsidian. “However, unregulated
expression of these cytokines by CAR-T or other adoptively-transferred
cells can potentially compromise safety and efficacy. Obsidian’s
technology allows the treating physician to control expression of IL12
and IL15 via the use of safe, FDA-approved small-molecule drugs, and the
preclinical data we present today demonstrate the elegance and
effectiveness of this approach.”

Highlights of the two preclinical presentations follow:

Abstract number 113: Exogenous In Vitro and In Vivo
Regulation of Interleukin-12 Secretion from T Cells Using Destabilizing
Domain Technology
Presenter: Dexue Sun
Session: Cancer –
Immunotherapy, Cancer Vaccines I

  • Construction of a single-chain regulated IL12 using a DD derived from
  • Demonstration of small molecule-regulated expression of IL12 in a
    variety of cell types including primary human T cells
  • Use of different promoters to tune expression level of the regulated
  • Demonstration of in vivo regulation of IL12 in adoptively
    transferred T cells
  • Development of a CD19 CAR construct co-expressing regulated IL12, with in
    data showing effective performance of the regulated cytokine

Abstract number 133: Dose dependent exogenous regulation of membrane
bound Interleukin-15-Interleukin-15 receptor alpha fusion protein for
adoptive T-cell therapy
Presenter: Christopher Reardon
Session: Cancer
– Targeted Gene & Cell Therapy I

  • Design of regulated membrane-bound IL15-IL15 Receptor Alpha (mbIL15)
    fusion construct incorporating DDs for pharmacologic control with
    small molecule ligands
  • Construction of mbIL15-DD construct incorporating human DDs, regulated
    by FDA-approved small-molecule drugs
  • Dose- and time-dependent regulation of mbIL15 expression in multiple
    cell types
  • Regulation of mbIL15 expression on primary human T cells in vivo

About Destabilizing Domains
Obsidian uses Destabilizing
Domains (DDs)
 to enable pharmacologic regulation of protein activity
for next-generation cell and gene therapies. Obsidian’s DDs are small,
fully-human protein domains that confer conditional stability to a fused
payload protein. In the absence of a specific small-molecule ligand, the
fusion protein is rapidly degraded, whereas in the presence of the
ligand, the fusion protein becomes stable and functional. Obsidian uses
this approach to equip engineered cells with controllable functions that
can be precisely tuned by the administration of non-immunosuppressive,
small-molecule medicines that are readily available and dispensed by the
treating physician.

About Obsidian Therapeutics
is a biotechnology company developing next-generation
cell and gene therapies with pharmacologic operating systems. Based upon
founding work on destabilizing domains by Professor Thomas Wandless, a
leading researcher in chemical and systems biology, Obsidian’s lead
programs are CAR-T products that incorporate controllable functions for
enhanced safety and efficacy. Obsidian was founded in 2015 by Atlas
Venture and is funded by a strong syndicate of venture investors. The
company is headquartered in Cambridge, Massachusetts. Please visit www.obsidiantx.com.


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Kathryn Morris, 914-204-6412