Synthekine Announces $107.5 Million Oversubscribed Series B Financing to Support Lead Programs to Clinical Proof of Concept, Advance Preclinical Programs and Platform

Financing co-led by Deerfield Management and Janus Henderson Investors, with additional new and existing investors participating

Proceeds to support clinical studies to proof-of-concept for selective IL-2 partial agonist, STK-012, and orthogonal IL-2 and CD-19 CAR-T system, STK-009 and SYNCAR-001

June 10, 2021 / MENLO PARK, Calif. — Synthekine Inc., an engineered cytokine therapeutics company, today announced that it has closed an oversubscribed $107.5 million Series B financing. The round was co-led by Deerfield Management and Janus Henderson Investors, with participation from RA Capital Management, Rock Springs Capital, Omega Funds, TCG X, Lilly Asia Ventures, and an undisclosed leading healthcare investor. Existing investors The Column Group, Samsara BioCapital, Canaan Partners, and Emerson Collective also participated in the round.

“Synthekine was founded two years ago to advance cytokine science and create optimized therapeutics in this important space. In that time, we have advanced two highly differentiated programs to IND-enabling development, expanded our pre-clinical pipeline of selective cytokine therapeutics through both internal development and licensing, and built a world-class team,” said Debanjan Ray, chief executive officer of Synthekine. “We are grateful for the support from this highly distinguished group of biotech investors and the continued support from our Series A investors. The proceeds of this financing put Synthekine in a position to generate clinical data with our lead programs, advance our preclinical pipeline towards clinical investigation, and mature our unique cytokine engineering platforms.”

Synthekine’s therapeutic pipeline is led by its selective IL-2 partial agonist, STK-012, and its orthogonal IL-2 and CD-19 CAR-T system, STK-009 and SYNCAR-001. At AACR 2021, data presented showed STK-012 induced potent anti-tumor activity while avoiding the toxicities that have hindered the development of IL-2 therapeutics, including vascular leak syndrome (VLS). Previously at ASH 2020, data presented showed STK-009 drove expansion of SYNCAR-001 in vivo, leading to deeper and more durable responses in pre-clinical models. Synthekine expects to move both programs into clinical investigation within the next year, with proceeds from the financing supporting clinical proof-of-concept data.

In addition to supporting advancement of Synthekine’s clinical pipeline, the financing will enable the company to advance additional programs toward clinical investigation. These include cytokine partial agonist programs for IL-10, IL-12 and IL-22 licensed by Synthekine in April 2021 from a new agreement with Stanford University through research conducted in the laboratory of Chris Garcia, PhD. While most cytokines are pleiotropic and drive a range of signaling responses across multiple cell types, which limits their potential as therapeutics, Synthekine’s partial agonists are tuned to trigger signaling in specific cell types, unlocking therapeutic benefit while avoiding toxicity.

Proceeds from this financing will also support the advancement of the company’s proprietary synthekine platform to pre-clinical proof of concept. This new class of cytokine therapeutics uses surrogate VHH agonists, in lieu of modified cytokines, to dimerize cytokine receptors and elicit biased signaling activities. Synthekine is building a modular approach with libraries of VHH agonists and is researching potential combinations that could have therapeutic application in oncology, immunology, and inflammation.

About Synthekine

Synthekine is an engineered cytokine therapeutics company developing disease-optimized treatments. The company uses immunological insights to guide targeted protein engineering to generate transformative medicines for cancer and autoimmune disorders. Using the principles of cytokine partial agonism and immunological specificity, Synthekine designs differentiated therapeutics to be both safe and efficacious. Its lead programs have shown promising efficacy and tolerability in preclinical studies, and it is developing additional cytokine partial agonists that selectively modulate key pathways of the immune system. For more information, visit

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