ACHM and XLRP
Achromatopsia (ACHM) is a rare, inherited retinal disease which causes impaired cone photoreceptor function. Patients experience light sensitivity so extreme that it can cause blindness during the day, a reduction in visual acuity, and color blindness.
X-linked Retinitis Pigmentosa (XLRP) is another rare, inherited retinal disease. It is caused by RPGR gene mutations. This condition is progressive and only affects males. It begins with nighttime blindness that then progresses into full legal blindness as the boy ages.
Applied Genetic Technologies Corporation (AGTC) has just announced that they have reached enrollment milestones in their Phase 1/2 clinical trials for both of these conditions.
Trials for ACHM
The two most common gene mutations causing ACHM are CNGB3 and CNGA2. AGTC is conducting two Phase 1/2 clinical trials, one for each of these mutations. For the ACHM CNGB3 trial, AGTC has completed enrollment for the dose escalation portion. This portion of the trial will evaluate both safety and efficacy of their gene therapy candidate called rAAV2tYF-PR1.7-hCNGB3.
AGTC has enrolled 12 individuals in the ACHM CNGB3 clinical trial and 6 in the ACHM CNGA3 clinical trial. The company’s goal is to release interim 6 month data from the dose escalation group of the CNGB3 trial by the second half of this year.
Trial for XLRP
AGTC’s gene therapy product candidate for XLRP is called rAAV2tYF-GRK1-RPGR. Their Phase 1/2 clinical trial for this candidate has just completed enrollment within the expansion group. The dose escalation portion of the trial includes 10 patients. 6 patients are enrolled in the expansion portion. The expansion part of the trial includes both pediatric and adult patients.
Like the ACHM candidate, this therapy utilizes AAV and is administered by subretinal injection. It received Orphan Medicinal Product Designation by the European Commission in 2016 as well as Orphan Drug Designation by the FDA back in 2017.
AGTC hopes to release interim 6 month data for the expansion group by the fourth quarter of this year. For the dose escalation group they expect this data by the third quarter.
Conclusion
For both of the aforementioned trials, the primary aim is evaluation of the safety of the treatments. Researchers will be evaluating the safety of AAV as well as the safety of the administration procedure. They will investigate treatment related AEs (both ocular and systemic) throughout the trials. Additionally, efficacy will be measured by evaluating changes in visual acuity, visual function, and visual fields. Patients quality of life will also be assessed.
This recent enrollment milestone for these trials is extremely exciting. Hopefully, we will see positive results from these trials announced soon.
You can read more about this research here.
