QLT Inc. has dosed its first patient in phase IIa proof-of-concept trial of QLT091001 in adult subjects with Impaired Dark Adaptation (IDA), a condition that results in decreased ability to recover visual sensitivity in the dark after exposure to bright lights.

The phase IIa proof-of-concept trial of QLT091001 is a randomized, multi-centre, parallelgroup, placebo-controlled study in adult subjects with IDA. Subjects (age 60 or older) with IDA, or impaired low luminance low contrast best corrected visual acuity (“LLLC BCVA”) in at least one eye and having no known ophthalmic pathologies to explain their condition other than early age-related macular degeneration (AMD) will be enrolled at sites in the US Subjects will be randomized to receive placebo or one of two different doses (10 or 40 mg/m2) of QLT091001 once per week for three consecutive weeks with one additional dose the day after the third dose.

The trial is designed to evaluate the safety profile and effects of QLT091001 on impaired dark adaptation time, glare recovery time and LLLC BCVA.

“We are pleased that dosing of the first patient has occurred on schedule, marking another significant milestone for QLT in the advancement of our synthetic oral retinoid programme in multiple indications,” said Jason M Aryeh, chairman of the Board. “This is an important step outside of rare orphan diseases with QLT091001, one which is designed to illustrate its potential in a significantly larger patient population. We are thankful to the clinical team, investigators, and of course, the patients for their participation in this study, and look forward to its outcome.”

Impaired Dark Adaptation (IDA) is a condition that results in decreased ability of the eye to recover visual sensitivity in the dark following exposure to bright lights (photobleaching) that gets worse with age.   Profoundly impaired dark adaptation is commonly associated with inherited retinal degenerations.  More recently, mild to moderate impaired dark adaptation has been associated with AMD and is proportionate to the severity of the disease. IDA (and/or impaired low luminance vision) may occur due to age-related inefficiencies in the retinoid cycle which results in slower regeneration of the light sensing pigment 11-cis-retinal in the eye and increased levels of free unbound opsin that lead to delayed dark adaptation and reduced retinal sensitivity.

Ultimately, these factors impair vision in low light or dark environments. The kinetics of the rod function have also been reported to be age-related, with the rod-mediated portion of the dark adaptation function significantly slower in older patients with normal retinal function than in younger adults.  This rod-mediated dark adaptation time is further slowed down in patients with early signs of AMD but with good visual acuity. IDA in this population causes symptomatic difficulties for functioning in dim light, especially after exposure to bright ambient light, and can hamper daily living activities such as driving, mobility, and workplace tasks.  Impaired mobility, in the form of falling, is one of the most common problems of old age. IDA is not a disease but a condition that can arise as a result of a number of pathologic or physiologic factors.  Improving this condition has the potential to not only improve a subject’s quality of life but also delay the development of degenerative retinal conditions with more severe visual outcomes.

QLT is a biotechnology company dedicated to the development and commercialization of innovative ocular products that address the unmet medical needs of patients and clinicians worldwide.