SAN DIEGO, CA, USA I July 24, 2019 I Synthorx, Inc. (NASDAQ: THOR), a clinical-stage biotechnology company developing optimized therapeutics for cancer and autoimmune disorders, announced today it has opened HAMMER, a global, Phase 1/2, first-in-human clinical trial of THOR-707, with Australia being the first region to enroll patients to date. In addition, the company has received clearance from the Food and Drug Administration (FDA) for the Investigational New Drug (IND) Application for THOR-707, paving the way for patient enrollment to proceed in the U.S. The single agent and combination arms of the trial are evaluating the safety, tolerability, pharmacokinetics, pharmacodynamics and anti-tumor activity of THOR-707 in patients with advanced or metastatic solid tumors.

“Our preclinical studies of THOR-707 have shown expansion of NK and CD8+ T cells, and durable anti-tumor effects without vascular leak syndrome (VLS), the toxicity that has limited the use of high-dose IL-2”, said Laura Shawver, Ph.D., president and chief executive officer of Synthorx. “Taken together, the favorable pre-clinical attributes of THOR-707 suggest that this may provide a differentiated product with clinically meaningful anti-tumor activity, minimal regulatory T cell-driven immunosuppression and convenient dosing schedules for patients”. This is the first Synthorin to enter the clinic engineered using Synthorx’ Expanded Genetic Alphabet platform, which enables the site-specific incorporation of novel amino acids to enhance the pharmacological properties of protein therapies like IL-2.

More information about the trial is available at https://clinicaltrials.gov/ct2/show/NCT04009681.

About THOR-707
THOR-707 is the first product candidate designed using Synthorx’ Expanded Genetic Alphabet platform technology. THOR-707 is a recombinant interleukin-2 (IL-2) cytokine that is pegylated at one specific site, intended to block engagement of the high affinity IL-2 receptor alpha chain while retaining potency on the beta chain, thereby maintaining potent effector T-cell anti-tumor activity while exhibiting an improved safety profile. In preventing engagement of the alpha chain of the receptor, the IL-2 product can be dosed for expansion of CD8+ T cells, without expansion of immune-suppressive regulatory CD4+ T cells, and without activation of non-lymphoid cells that trigger the sometimes-fatal complication of vascular leak syndrome, observed with approved recombinant IL-2 (aldesleukin). This site-specific pegylation also increases the pharmacokinetic properties of THOR-707, including a longer half-life.

About Synthorx
Synthorx, Inc. is a biotechnology company focused on prolonging and improving the lives of people with cancer and autoimmune disorders. Synthorx’ 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 for the treatment of solid tumors as a single agent and in combination with an immune checkpoint inhibitor. The company was founded based on important discoveries at The Scripps Research Institute. The company is headquartered in La Jolla, Calif. For more information, visit www.synthorx.com.

SOURCE: Synthorx