Claris reports visual acuity gains with experimental LSCD treatment
pharmafile | October 21, 2026 | News story | |Â Â Opthalmology, cytology, ophthalmicsÂ
Claris Biotherapeutics has reported visual acuity improvements with its experimental therapy CSB-001 in a proof-of-concept study involving patients with limbal stem cell deficiency (LSCD), a rare eye-surface disorder that can cause severe vision loss or blindness.
Data presented at the American Academy of Ophthalmology (AAO) 2026 Annual Meeting showed that 41.4% of treated eyes gained at least 15 letters on a visual acuity chart by week 20, compared with none of the untreated control eyes. A gain of at least 10 letters was recorded in 55.2% of treated eyes, against 5% of controls.
The open-label study assessed 49 eyes from 39 participants with central corneal conjunctivalisation and reduced best-corrected visual acuity. Twenty-nine eyes received CSB-001, an ophthalmic solution containing recombinant human deleted hepatocyte growth factor, four times daily across two eight-week treatment periods separated by a one-month dosing break. The remaining 20 eyes served as untreated controls.
Claris reported that visual gains persisted after treatment ended. Among treated eyes, 50% maintained improvements of at least 15 letters and 81% maintained gains of at least 10 letters for 16 weeks after treatment. The company also reported a correlation between anatomical changes and visual improvement, and described the treatment as generally safe and well tolerated.
LSCD results from a deficiency or dysfunction of limbal stem cells, which maintain and repair the corneal surface. There are currently no pharmacological treatments approved specifically for the condition.
Claris plans to begin two pivotal studies in the first half of 2027, comparing CSB-001 with vehicle in approximately 400 participants. Unlike the proof-of-concept study, these trials are expected to use continuous dosing, with visual acuity being the primary efficacy endpoint, supported by anatomical measures.
The findings provide an early clinical signal, but the planned pivotal studies will need to establish whether the improvements are reproducible and demonstrate the treatment’s safety and efficacy in a larger population
Pic: Colin Lloyd
