Supported by positive proof-of-concept data, Claris Biotherapeutics has closed a $118 million Series B round that will fund the company through a pivotal study beginning next year. If successful, their lead candidate could become the first pharmacological treatment for a rare condition causing progressive blindness.
The fundraising was co-led by Samsara BioCapital and Catalio Capital Management, along with a number of new and existing investors such as Sofinnova Investments and Novo Holdings. In parallel, the company has appointed a new CEO, chief commercial officer, and chairman as it prepares for the commercialization of its lead drug candidate. From now on, founding CEO Clarke Atwell will serve as the company’s chief operating officer.
Based in New Jersey, Claris Bio was founded by ophthalmology experts with the goal of developing disease-modifying therapies for corneal diseases that currently have limited or no treatment options other than surgery. The company’s scientific platform is built on research originally conducted at Harvard Medical School and Massachusetts Eye and Ear Infirmary.
Claris Bio’s lead candidate, CSB-001, is being developed to treat vision loss caused by limbal stem cell deficiency (LSCD), a disease marked by the progressive loss or dysfunction of the stem cells that maintain and regenerate the outermost layer of the cornea. As the disease advances, the cornea becomes increasingly opaque, blurring vision and eventually leading to blindness.
Despite the burden LSCD imposes on daily functioning and quality of life, there are currently no approved drug therapies. The condition is managed by addressing symptoms, and advanced disease is sometimes addressed with complex, highly specialized surgical interventions that frequently require long-term immunosuppression.
Formulated as an eye drop, CSB-001 is designed to target the underlying causes of LSCD. The activa compound is a recombinant form of the deleted hepatocyte growth factor (dHGF), a naturally occurring protein involved in tissue repair. Preliminary data from an ongoing proof-of-concept study in 63 LSCD patients has shown that the therapy promotes the regeneration of the cornea while reducing inflammation and fibrosis, leading to substantial improvements in visual acuity.
Alongside this proof-of-concept study, which will conclude later this year, Claris Bio is conducting a non-interventional study to better understand the natural history of LSCD, assess how the disease is managed in clinical practice, and identify potential trial sites and participants for its upcoming pivotal program.
The company plans to launch two Phase III studies in the first half of 2027, enrolling about 400 patients to evaluate CSB-001. If these trials are successful and the drug candidate eventually receives regulatory approval, CSB-001 could become the first non-surgical therapy for LSCD, offering patients a more accessible and reliable treatment option.
“The prospect of significantly improving vision with a convenient eye drop is a tremendous advance,” said Stephen Brady, newly appointed president and CEO of Claris Biotherapeutics. “The strong interest in CSB-001 reflects both its promise for patients and commercial potential. With the company financed through Phase III and the team in place to execute, we’re ready to advance CSB-001 from a position of strength.”
