Atsena Therapeutics announces positive 12-month safety, efficacy Data from Phase I/II clinical trial of ATSN-101

Atsena Therapeutics announced positive 12-month safety and efficacy data from the ongoing Phase I/II trial of ATSN-101, the company’s investigational gene therapy for the treatment of GUCY2D-associated Leber congenital amaurosis (LCA1).

According to a news release from the company, at 12 months post-treatment, ATSN-101 showed clinically meaningful improvements in vision at the highest dose with no serious treatment-emergent adverse events.¹

The FDA recently granted Regenerative Medicine Advanced Therapy (RMAT) designation to ATSN-101.¹ Atsena noted in its news release it has also received orphan drug designation from the FDA for ATSN-101 for the treatment of LCA1.

LCA1 is a monogenic eye disease that disrupts the function of the retina and is caused by mutations in the GUCY2D gene and results in early and severe vision impairment or blindness. According to the company’s news release, GUCY2D-LCA1 is among the most common forms of LCA, affecting roughly 20 percent of patients who live with this group of inherited retinal diseases. There are currently no approved treatments for LCA1.1

Kenji Fujita, MD, chief medical officer of Atsena Therapeutics, pointed out that the company continues to be encouraged by the data emerging from its Phase I/II trial of ATSN-101 in patients with GUCY2D-associated LCA1.

“The durability of clinically meaningful visual improvements in the absence of serious treatment-related adverse events at the 12-month mark underscore the safety, tolerability, and efficacy of our subretinal gene therapy,” he said in the news release. “We believe the 12-month findings provide solid proof of concept that ATSN-101 will exceed the requirements set by the US Food and Drug Administration for ultimate approval. We are exploring partnering and out-licensing options to advance ATSN-101 into a pivotal trial.”

According to the company, in the Phase I/II trial, 15 patients ages 12 to 76 received unilateral subretinal injections of ATSN-101. In the trial, 3 adult cohorts (N=3 each) were treated with 3 ascending doses. Subsequently, 1 adult and 1 pediatric cohort (N=3 each) were treated at the high dose. In total, 9 patients received the high dose.

Moreover, the company noted in its news release that after 12 months, no serious treatment-emergent adverse events were reported. The clinical trial also found that ocular inflammation was mild and reversible with steroid treatment.

The company also noted that for high-dose patients, the mean (SE) change from baseline in dark-adapted full-field stimulus testing (FST) (white stimulus) was greater in treated eyes compared with untreated eyes at all 6 follow-up visits, and some patients exhibited more than 10,000-fold improvements in retinal sensitivity.

Of the 6 high-dose patients who were tested with multi-luminance mobility testing (MLMT), 3 improved by ≥2 levels compared to baseline (when available) or to the untreated eye, and all three demonstrated a maximum score of 6 in the treated eye. At 12 months, patients receiving the high-dose demonstrated a statistically significant improvement in best-corrected visual acuity (BCVA).

Paul Yang, MD, PhD, Associate Professor of Ophthalmology at OHSU School of Medicine, pointed out in the news release that the noteworthy improvements in key visual parameters demonstrate the potential of ATSN-101 to make a meaningful impact on the lives of patients affected by GUCY2D-associated LCA1.

“As LCA1 causes early and severe vision impairment or blindness and there are no approved treatments, ATSN-101 has the potential to fill a significant unmet need within the LCA community,” he said in the release.

According to the Atsena news release, the 12-month data have been accepted for presentation at the 47th Annual Macula Society Meeting, which will be held February 7-10, 2024, in Palm Springs, California.

The US Food and Drug Administration (FDA) recently granted Regenerative Medicine Advanced Therapy (RMAT) designation to ATSN-101. Atsena has also received orphan drug designation from the FDA for ATSN-101 for the treatment of LCA1.

Reference:

1. Therapeutics A. Atsena Therapeutics Announces Positive 12-month Safety and Efficacy Data from Ongoing Phase I/II Clinical Trial of ATSN-101 in Patients with Leber Congenital Amaurosis Caused by Biallelic Mutations in GUCY2D (LCA1). GlobeNewswire News Room. Published December 4, 2023. Accessed December 4, 2023. https://www.globenewswire.com/news-release/2023/12/04/2789910/0/en/Atsena-Therapeutics-Announces-Positive-12-month-Safety-and-Efficacy-Data-from-Ongoing-Phase-I-II-Clinical-Trial-of-ATSN-101-in-Patients-with-Leber-Congenital-Amaurosis-Caused-by-Bi.html