Los Angeles, March 31, 2026 — Trethera Corporation (“Trethera”), a clinical-stage biopharmaceutical company developing first-in-class therapies for cancer, autoimmune, and neuroimmune diseases, today announced a clinical collaboration with Massachusetts General Hospital (MGH) to evaluate TRE-515 in up to six patients with advanced amyotrophic lateral sclerosis (ALS, also known as Lou Gehrig’s disease) under the FDA Expanded Access program. TRE-515 inhibits deoxycytidine kinase (dCK), a key enzyme activated during abnormal cell division and inflammatory signaling. Emerging evidence suggests that inflammation contributes to ALS.
“This collaboration with MGH follows our encouraging ALS clinical findings last year and is an important step in expanding our clinical efforts to understand and treat this devastating disease,” said Dr. Ken Schultz, Trethera Chairman and CEO. “MGH was among the first academic centers to engage with Trethera, and we hope to expand participation to other leading institutions following the successful conclusion of this trial.”
“Therapeutic options for ALS remain limited, and there is a continuing need to explore novel approaches for patients facing this serious disease,” said Dr. Merit Cudkowicz, Executive Director of the Massachusetts General Brigham Neuroscience Institute and principal investigator for the trial. “We are pleased to collaborate with Trethera to further evaluate this investigational therapy.”
MGH, the original and largest teaching hospital of Harvard Medical School, is internationally recognized as a leading ALS research center and plays a central role in accelerating development for new ALS therapies. The program is led by Dr. Cudkowicz, one of the foremost experts in ALS clinical research. Under her leadership, MGH has become a premier center for evaluating emerging therapies for patients with ALS.
During the collaboration, up to six patients with advanced ALS will enroll in a trial conducted by MGH. The trial will evaluate the safety and tolerability of TRE-515 while tracking disease trajectory over time. In parallel, investigators will collect pharmacodynamic biomarkers reflecting TRE-515 pathway activity alongside established ALS disease biomarkers such as neurofilament light chain (NfL). Patients will undergo monthly clinical assessments including the Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R) and Slow Vital Capacity (SVC). This integrated clinical and biomarker approach may help (i) inform the biological activity of TRE-515 in ALS patients, (ii) guide future patient selection, and (iii) serve as a platform for larger clinical trials.
“We are particularly encouraged by the potential of treating ALS with TRE-515 given its ability to selectively modulate inflammation and its favorable safety profile observed to date,” said Dr. Lawrence Steinman, member of Trethera’s Scientific Advisory Board and Professor of Neurology at Stanford University. “While this initial pilot study is small, it builds on promising early clinical observations. A favorable readout could support expansion into larger, more definitive trials and further advance the clinical development of TRE-515 in ALS.”
Last year, Trethera reported results from a single patient with advanced ALS treated under the FDA Expanded Access program in collaboration with Dr. Steinman, UCLA, Cedars-Sinai, and Saint John’s Health Center. The 87 year-old patient had previously received 11 therapies over 3.5 years, including stem cell treatments, without meaningful clinical benefit. During treatment with TRE-515, objective measures suggested disease stabilization, with the rate of forced vital capacity decline slowing from approximately 1.2% per week prior to treatment to 0.5% and 0.2% per week after three and 6.5 months of treatment, respectively. No adverse events attributable to TRE-515 were reported. The patient and his family also noted improvements in selected quality-of-life measures, including muscle strength (see Figure 1) and vocalization. Treatment was discontinued following a fall at home, and the patient later died from pneumonia, consistent with the natural progression of advanced ALS.
Discover the ALS Patient Who Inspired Our Research
About Amyotrophic Lateral Sclerosis
Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder that affects nerve cells in the brain and spinal cord, leading to loss of muscle function and control. ALS is biologically heterogeneous and has been associated with mutations in more than 20 genes, although most cases are sporadic and not inherited. The disease places a profound burden on patients and families, and there remains no cure. Life expectancy following diagnosis is typically two to five years.
Sources: Lancet.2022 Oct 15;400(10360); EurJNeurol.2020 Jul 7;27(10); SurgNeuro.2015 Nov 16;6:(171).
About Trethera and TRE-515
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 administered capsule. 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, and certain autoimmune diseases might also respond to TRE-515 treatment. The FDA has designated TRE-515 a Fast Track drug for prostate cancer and an Orphan Drug for two autoimmune neurologic diseases. 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 trethera.com or e-mail Investor Relations at ir@trethera.com. You can also follow Trethera on Facebook and LinkedIn.
Note on Forward-Looking Statements
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