Applied Genetics Technologies Corp. announced positive interim six-month data from the dose-escalation cohorts of its ongoing Phase 1/2 clinical trials, which are evaluating adeno-associated virus (AAV)-based gene therapies in patients with achromatopsia due to mutation in the ACHM CNGB3 or ACHM CNGA3 genes. The interim results from both studies demonstrate encouraging signs of biologic activity and a favorable safety profile. The company plans to report data from additional dose groups, age groups and time-points in the second half of 2020.
The data reported are from 22 patients who have been dosed in the initial groups of the trials, comprising 13 patients in the ACHM CNGB3 trial and 9 patients in the ACHM CNGA3 trial. Data from both trials continue to demonstrate a favorable safety profile with no dose-limiting inflammatory responses observed.
These data also demonstrate encouraging signs of biologic activity, as shown by positive changes in light discomfort testing and encouraging patient anecdotes describing real-world improvements in visual function. The company is currently dosing two higher dose groups in adults and three groups of pediatric patients at the three highest dose groups in both trials. The company will use the additional data, which is expected to be available in the second half of 2020, to decide whether the candidates should advance to pivotal trials.
About Achromatopsia (ACHM)
Achromatopsia (ACHM) is an inherited condition caused by mutations in one of several genes, with the two most common being mutations in either the CNGB3 or CNGA3 genes. ACHM is associated with extremely poor visual acuity (most affected individuals are legally blind), extreme light sensitivity resulting in daytime blindness, and complete loss of color discrimination. There is no specific treatment for ACHM, although deep red tinted glasses or contact lenses can reduce symptoms of light sensitivity and daytime blindness.
About AAV gene therapy product candidates
AGTC is currently developing two separate AAV gene therapy product candidates for the two most prevalent forms of ACHM, caused by either a genetic mutation in the CNGB3 or CNGA3 genes. Together, these two genetic mutations account for up to 75% of the ACHM patient population. In animal models of ACHM, untreated animals have the same signs of abnormal visual function as humans with ACHM, which is most dramatically manifested by daytime blindness under bright light conditions. Treatment of ACHM animal models with an AAV vector expressing the CNGB3 or CNGA3 protein resulted in long-term improvement in visual function.