Synthekine Inc., an engineered cytokine therapeutics company, today announced the dosing of the first patient in a Phase 1a/1b clinical trial of its IL-2 partial agonist, STK-012, for the treatment of solid tumors. STK-012 is designed as an alpha/beta-biased IL-2 partial agonist to selectively stimulate antigen-activated T cells, which are associated with potent anti-tumor activity, and avoid stimulation of toxicity causing immune cells, such as natural killer cells.

“We are proud to begin this year with the important milestone of dosing the first patient in our Phase 1 trial of STK-012,” said Debanjan Ray, chief executive officer of Synthekine. “STK-012 is a highly differentiated IL-2 partial agonist tuned to expand the therapeutic index of IL-2 by biasing towards efficacy driving antigen-activated T cells and away from toxicity causing lymphocytes, such as natural killer (NK) cells. STK-012 is the first program from our broad portfolio of biased cytokines to enter the clinic, and its rapid progress into clinical investigation further highlights our team’s tremendous ability to execute efficiently and move our pipeline forward.”

Aldesleukin (recombinant IL-2) has shown to be active in certain cancers, but its use is limited due to life threatening toxicities such as capillary leak syndrome (CLS). Synthekine presented preclinical data at AACR 2021 demonstrating a mouse surrogate of STK-012 achieved superior tumor regression compared to both wild-type mouse IL-2 and a non-alpha-IL-2 agent, representing a different approach to biasing IL-2. In toxicity models, the mouse surrogate of STK-012, unlike these same comparators, was well tolerated and did not induce CLS. In non-human primate studies, STK-012 avoided lymphopenia, NK cell activation and CLS induction, which was observed with both aldesleukin and a non-alpha-IL-2 agent.

The Phase 1a/1b clinical trial is an open-label, multi-center study enrolling patients with advanced solid tumors. The dose escalation portion of the study will evaluate STK-012 both as a monotherapy and in combination with pembrolizumab. Following completion of the dose escalation, Synthekine will initiate expansion cohorts with STK-012. For additional information about the trial, please visit www.clinicaltrials.gov using the identifier NCT05098132.

About Synthekine

Synthekine is harnessing the potential of cytokine therapeutics to develop selective immunotherapies designed to improve the treatment paradigm of cancer and inflammatory disease. Using insights on cytokine structure and function, the company engineers therapeutics designed to unlock the full efficacy potential of cytokines while avoiding their associated toxicities. Synthekine is applying principles of cytokine partial agonism and immunological specificity across multiple protein engineering platforms to create a broad and deep pipeline of product candidates. These novel immunotherapies include modified cytokines, cytokine-enhanced cell therapies and surrogate cytokine agonists. For more information, visit www.synthekine.com, and follow us on Twitter @synthekine and LinkedIn.

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