Safety Review Committee Advances Trethera Phase 1 Solid Tumors Trial to Next Dose After First Patient Cohort Achieves Primary Endpoint

Los Angeles, December 9, 2021 — Trethera Corporation (“Trethera”), a clinical stage biopharmaceutical company committed to developing novel drugs targeting nucleotide metabolism for the treatment of cancer and autoimmune diseases, announced that the first patient cohort completed their full dose cycle with no serious adverse events (SAEs) in its multi-site Phase 1 oncology trial. The safety and tolerability of TRE-515, a first-in-class drug targeting the enzyme deoxycytidine kinase (dCK), is being evaluated in up to 36 patients with various solid tumor malignancies.

No SAEs and no drug-related treatment-emergent adverse events were observed during the administration of TRE-515 as a monotherapy treatment. The independent safety review committee (SRC) evaluated the first cohort data and unanimously supported study continuation and dose escalation. The clinical trial will now proceed to the second of five dose levels, and interim data is expected by the end of next year. “We are pleased to have the SRC endorsement for dose escalation and to reach this milestone in TRE-515 development,” said Dr. Ken Schultz, Trethera Chairman and CEO. “We are grateful to the patients and clinical sites for their participation and look forward to continued collaboration as we commence enrollment of the second cohort.”

TRE-515 is an orally delivered therapeutic engineered to inhibit dCK, the key enzyme in the nucleoside salvage pathway. A common characteristic of solid tumors is that they require elevated levels of nucleotides to support rapid cellular DNA replication and accelerated malignant growth. Cancer cells overexpress dCK to help maintain these elevated nucleotide levels. In contrast, dCK activity is highly restricted in healthy adult human cells. By targeting dCK, scientists hope to selectively and effectively deprive cancer cells of this needed nucleotide source, thereby blocking tumor progression.

About Trethera

Trethera is a clinical stage privately held biopharmaceutical company dedicated to pioneering the development of novel treatments for autoimmune diseases and cancers. Founded by prominent UCLA scientists, Trethera is led by experienced management and board members. Trethera’s innovative approach to targeting nucleotide metabolism led to the development of TRE-515, an orally taken capsule twice designated by the FDA as an Orphan Drug. TRE-515 is a first-in-class clinical stage drug that inhibits deoxycytidine kinase (dCK), the rate-limiting enzyme in the nucleoside salvage pathway, one of two biosynthetic pathways that generate DNA precursors. It is believed that some forms of cancer may be preferentially dependent on the salvage pathway to support tumor growth. Certain autoimmune diseases might also respond to TRE-515 treatment. Trethera is developing TRE-515 for use as a monotherapy or in combination, to precisely target a metabolic vulnerability of cancer or autoimmune diseases that will transform outcomes for patients.

For more information, please visit us at

Note on Forward-Looking Statements

All statements other than statements of historical facts included in this press release that address activities, events or developments that Trethera believes or anticipates will or may occur in the future are “forward-looking statements,” which may often, but not always, be identified by the use of such words as “may,” “might,” “will,” “will likely result,” “would,” “should,” “estimate,” “plan,” “project,” “forecast,” “intend,” “expect,” “anticipate,” “believe,” “seek,” “continue,” “target” or the negative of such terms or other similar expressions. Although Trethera has a reasonable basis for the forward-looking statements contained herein, Trethera cautions that such statements are based on current expectations about future events and are subject to risks, uncertainties and factors relating to medical and scientific research, all of which are difficult to predict and many of which are beyond Trethera’s control, that may cause actual results to differ materially from those expressed or implied by the forward-looking statements in this press release. These potential risks and uncertainties include, without limitation: the extent to which development of any novel cancer therapies or therapies for autoimmune diseases succeeds; whether Trethera would obtain the necessary regulatory approvals to commence human trials or commercialize TRE-515 or any novel therapies resulting from such research; Trethera successfully implementing its growth strategy, including that relating to its disease therapies; the effects of the global Covid-19 pandemic; changes in economic conditions; competition; and risks and uncertainties applicable to the business of Trethera. The statements in this press release speak only as of the date hereof and Trethera does not undertake any obligation to update, amend or clarify these forward-looking statements whether as a result of new information, future events or otherwise. Trethera intends that all forward-looking statements be subject to the safe-harbor provisions of the Private Securities Litigation Reform Act of 1995.