Synthorx to Present Preclinical Data for THOR-707, a "Not-Alpha" IL-2 Synthorin, for the Treatment of Solid Tumors at SITC 2018

SAN DIEGO, Nov. 9, 2018 /PRNewswire/ -- Synthorx, Inc., a biotechnology company using a first-of-its-kind Expanded Genetic Alphabet platform technology to discover and develop optimized biologics for cancer and autoimmune disorders, today announced company researchers will present results of preclinical studies demonstrating the safety and anti-tumor effects of its lead product candidate THOR-707, a "not-alpha" Synthorintm of interleukin-2 (IL-2), for the treatment of solid tumors at the Society for Immunotherapy of Cancer (SITC) 33^rd Annual Meeting. Marcos Milla, Ph.D., chief scientific officer of Synthorx, will present the poster on Friday, November 9, from 12:45 ? 2:15 p.m. and 6:30 ? 8:00 p.m. ET at the Walter E. Washington Convention Center in Washington, D.C.

The study, titled "THOR-707: An engineered IL-2 for the treatment of solid tumors with superior preclinical  efficacy and safety evidence," investigates the application of Synthorx's Expanded Genetic Alphabet platform technology to engineer THOR-707, a variant of recombinant human IL-2 that is pegylated at one specific site and designed to kill tumor cells without inducing vascular leak syndrome (VLS), a toxicity associated with aldesleukin, an approved recombinant IL-2. Aldesleukin was approved by the U.S. Food and Drug Administration over 25 years ago for the treatment of patients with metastatic renal cell carcinoma and metastatic melanoma. However, widespread use of aldesleukin has been limited by toxicities, which include life-threatening and sometimes fatal VLS, as well as by its short half-life, requiring courses of dosing of three times per day over eight days.

In Synthorx's preclinical studies, THOR-707 induces molecular markers of T cell activation and the proliferation of peripheral NK and CD8+ effector T cells in vivo. However, dosing of THOR-707 has minimal effect on molecular and clinical markers of VLS, even at high exposures. Analysis of the effect of THOR-707 in syngeneic mouse tumor models showed that THOR-707 induced infiltration of CD8+ T effector cells into tumors and elicited anti-tumor effects alone and in combination with a PD-1 immune checkpoint inhibitor. 

About Synthorx
Synthorx, Inc. is a biotechnology company focused on prolonging and improving the lives of people with cancer and autoimmune disorders. Synthorx's proprietary, first-of-its-kind Expanded Genetic Alphabet platform technology expands the genetic code by adding a new DNA base pair and is designed to create optimized biologics, referred to as Synthorins. A Synthorin is a protein optimized through incorporation of novel amino acids encoded by the new DNA base pair that enables site-specific modifications, which enhance the pharmacological properties of these therapeutics. The company's lead product candidate, THOR-707, a variant of IL-2, is in development in multiple tumor types as a single agent and in combination with an immune checkpoint inhibitor.  The company was founded based on important discoveries in Dr. Floyd Romesberg's lab at The Scripps Research Institute. The company is headquartered in La Jolla, Calif.

SOURCE Synthorx, Inc.