Cyllene Therapeutics

Cyllene Therapeutics, formerly known as EG 427, is a biotechnology company developing gene therapies for neurological diseases. Founded in 2019 by Philippe Chambon, François Giuliano, and Alberto Epstein, the company is headquartered in Paris, France. The firm's name changed to Cyllene Therapeutics in July 2026 to coincide with a €33 million Series C financing round, honoring the mythical birthplace of Hermes, the namesake of its core technology platform.The company's proprietary HERMES platform utilizes a non-replicating Herpes Simplex Virus type 1 (nrHSV-1) vector. This vector is engineered to deliver disease-modifying transgenes with high precision to targeted neurons in the peripheral and central nervous systems, offering durable gene expression without viral replication. The technology originated from the Elpis project at the END-ICAP laboratory, a joint effort of Université Paris-Saclay, UVSQ, and Inserm.Cyllene's lead asset, EG110A, is a gene therapy candidate for treating severe neuro-urology conditions, specifically neurogenic detrusor overactivity (NDO), a bladder dysfunction common in patients with spinal cord injuries. EG110A is designed to selectively silence the type C sensory neurons responsible for bladder overactivity while preserving normal function. The treatment is administered via injection into the bladder wall. Following IND clearance from the US FDA in June 2024, the company initiated a Phase 1/2 study in the United States. Recent clinical data has shown significant and sustained reductions in urinary incontinence episodes. The company plans to start a pivotal Phase 2b/3 study in 2027 and is also exploring EG110A for overactive bladder (OAB).Cyllene's business model is centered on research and development, funded through venture capital. The company has raised over USD 50 million, including a €27 million Series B in 2025 and a €33 million Series C in 2026. Key investors include GordonMD Global Investments, Merck Ventures, Andera Partners, and Bpifrance. The company's strategy involves advancing its candidates through clinical trials to demonstrate value, with the long-term goal of either partnering with larger pharmaceutical firms or commercializing the therapies independently. Beyond urology, Cyllene is expanding its pipeline to address other neurological indications, such as chronic pain and migraine.Keywords: gene therapy, neurology, non-replicating HSV-1, HERMES platform, EG110A, neurogenic bladder, neurogenic detrusor overactivity, overactive bladder, spinal cord injury, Philippe Chambon, Paris biotech, DNA medicine, vector technology, peripheral nervous system, central nervous system, neuro-urology, clinical trials, Series C, Merck Ventures