LCA and RP patients show functional improvements with oral synthetic retinoid

Repeat courses of treatment with oral 9-cis-retinyl acetate (QLT091001, QLT Inc) in patients with Leber congenital amaurosis (LCA) or retinitis pigmentosa (RP) due to genetic mutations in RPE65 or LRAT had an acceptable safety profile and led to sustained visual improvements, according to the results of RET IRD 02, a multicenter Phase 1b study.

The findings were presented by Hendrik P. Scholl, MD, MA, at the Association for Research in Vision and Ophthalmology annual meeting.

The study enrolled patients treated with a single 7-day course of QLT091001 10 or 40 mg/m2 in an earlier study.  In RET IRD 02, patients received up to 3 7-day courses of the oral synthetic cis-retinoid at doses of 10, 40, or 60 mg/m2.

Ten (77%) of 13 LCA patients and 12 (86%) of 14 RP patients were “responders” (met threshold criteria for improvement) in at least 1 eye in either functional retinal area (Goldmann visual field) or ETDRS visual acuity.

Most adverse events were mild (78%) or moderate (18%) in intensity, consistent with the retinoid class, and transient and/or reversible, reported Dr. Scholl, The Dr. Frieda Derdeyn Bambas Professor of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD.

“We must be cautious because this is not placebo-controlled study. However, these are diseases where patients decline over time and never get better. So, when you see any improvement, it is quite a surprise,” he said.