Genascence to Present Full Data from Phase 1 Clinical Trial on GNSC-001, Company's Lead Program in Osteoarthritis, at European Society of Gene & Cell Therapy 30th Annual Congress

• Results showed GNSC-001 met the primary safety endpoint and was well-tolerated in all study subjects, including 12-month follow-up.
• Study findings noted elevated IL-1Ra expression in synovial fluid and an encouraging trend in symptomatic improvement.
• Osteoarthritis affects more than 30 million Americans and is the leading cause of disability; GNSC-001 may have a role to play in helping these patients in a safe and efficacious manner.

PALO ALTO, Calif., Oct. 24, 2023 /PRNewswire/ -- Genascence Corporation ("Genascence"), a clinical-stage biotechnology company revolutionizing the treatment of prevalent musculoskeletal diseases with gene therapy, today announced that data from the Phase 1 clinical trial of GNSC-001 for the treatment of osteoarthritis (OA) demonstrated that it was safe and well tolerated. The study findings also showed that a single intra-articular injection of GNSC resulted in elevated interleukin-1 receptor antagonist (IL-1Ra) expression over baseline in synovial fluid for the length of the 12-month study. Additionally, treatment with GNSC-001 showed a trend in improvement of pain and function scores in all study participants, with a limited amount of disease progression in this first-in-human study. These data will be delivered in a poster presentation at the European American Society of Gene & Cell Therapy's (ESGCT) 30^th Annual Congress being held October 24-27, 2023, in Brussels, Belgium.

"These study results provide encouraging preliminary evidence that GNSC-001 may have a role to play in helping OA patients in a safe and effective manner," said Annahita Keravala, Ph.D., founder and chief scientific officer (CSO) of Genascence.

GNSC-001 is a genetic medicine – a recombinant adeno-associated viral (AAV) vector expressing an optimized form of IL-1Ra, a naturally occurring protein that blocks interleukin-1 (IL-1) signaling. IL-1 is considered one of the key mediators involved in the pathogenesis of OA, causing inflammation, joint pain, as well as cartilage destruction. GNSC-001 is designed to offer long-term, sustained inhibition of IL-1 following a single injection into the affected joint.

"Osteoarthritis is incapacitating, causing years of pain and disability for people living with the disease, and there are no currently available treatments to slow down disease progression. We believe GNSC-001 can deliver transformative results and we are excited to advance our clinical program so we can help patients suffering from this disabling disease," said Thomas Chalberg, Ph.D., founder and CEO of Genascence.

Title: Adeno-associated virus-mediated gene therapy for knee osteoarthritis – A phase I clinical trial report
Abstract Number: P553
Date: October 25, 2023, 5:00-6:15 PM CEST and October 26, 2023, 8:30-9:30 PM CEST
Presenter: Annahita Keravala, Ph.D., founder and CSO, Genascence

In this investigator-sponsored Phase 1 single-arm, open-label, dose-escalation clinical trial of GNSC-001, a total of nine subjects with knee OA were enrolled and monitored for one year. Three subjects were treated in each of three cohorts, receiving either 1x10¹¹ vector genomes (vg)/knee (low dose), 1x10¹² vg/knee (mid dose), or 1x10¹³ vg/knee (high dose) GNSC-001 delivered by intra-articular injection. The primary endpoint is safety and tolerability. Additional measures include levels of circulating viral genomes, immune response to the vector, blood and urine analysis, and physical examination. Although the study was not powered for efficacy and had no control group, patients reported pain via VAS (0-10) and pain and function via WOMAC. Knee joints were imaged by X-ray and MRI upon study entry and after one year.

Results showed that GNSC-001 met the primary safety endpoint with no dose-limiting toxicity up to 1x10¹³ vg high dose. There were no vector-related adverse events in seven of the nine subjects; two subjects experienced mild/moderate knee effusions, which resolved with ice and rest. Clinical trial participants developed various degrees of anti-AAV neutralizing antibodies after injection of GNSC-001, but no capsid targeted T-cell response was detected. Small amounts of viral genomes were found in peripheral blood, beginning one day after injection and clearing within four weeks in most subjects. Injection of GNSC-001 was associated with increased concentrations of IL-1Ra in synovial fluid, which remained elevated for 12 months of follow up. Pain and function scores showed an encouraging trend toward improvement, and no one got worse following injection of GNSC-001.

The study was supported by funding from the U.S. Department of Defense Peer Reviewed Medical Research Program (PRMRP). More information is available at https://clinicaltrials.gov/ct2/show/NCT02790723.

Abstracts can be accessed via the conference website at www.esgctcongress.com.

About Osteoarthritis (OA) of the Knee
Osteoarthritis (OA) is a degenerative joint disease that is the leading cause of disability. It is characterized by destruction of cartilage and structural changes in bone within the joint, which contribute to pain and loss of joint function. Osteoarthritis affects more than 30 million Americans and is increasing as a result of the aging population and increasing prevalence of obesity. Osteoarthritis represents a major economic burden, owing to direct medical costs and loss of productivity. Each year, millions of patients are treated for knee OA with NSAIDs, opioids, and steroid injections into the knee to manage their knee pain. There are no currently available therapies known to alter or slow down OA progression.

About Genascence Corporation
Genascence, a clinical-stage biotechnology company revolutionizing the treatment of prevalent musculoskeletal diseases with gene therapy, is developing life-changing treatments for highly prevalent conditions affecting millions of people. The company was founded in 2017 with technology licensed from three leading U.S. research institutions: Mayo Clinic, University of Florida, and NYU Langone Health. Headquartered in Palo Alto, California, Genascence's founders and leadership team have deep experience in the design, development, and manufacturing of successful gene therapies and biological medicines. For more information, please visit www.genascence.com.

SOURCE Genascence