Genascence Reports Safe Tolerability of GNSC-001 in Phase 1b DONATELLO Trial

Genascence Corporation, a biotechnology firm based in Palo Alto, California, is making strides in the treatment of musculoskeletal diseases with its innovative gene therapy solutions. Recently, the company announced promising interim findings from the Phase 1b DONATELLO clinical trial, which is assessing the investigational gene therapy product GNSC-001 for knee osteoarthritis (OA). This therapy utilizes an adeno-associated viral vector to deliver interleukin 1 receptor antagonist (IL-1Ra), which acts as a powerful inhibitor of interleukin 1 (IL-1). The six-month interim analysis of the trial revealed that GNSC-001 is safe and well-tolerated across various doses, with significant biomarker data supporting its potential efficacy.

Dr. Jeymi Tambiah, the Chief Medical Officer of Genascence, emphasized the significance of these interim results in the company's quest to redefine osteoarthritis treatment. The sustained expression of IL-1Ra and the favorable safety profile of GNSC-001 suggest that this gene therapy could serve as a one-time treatment option for individuals suffering from this debilitating condition. The insights gained from the DONATELLO trial are expected to inform future discussions with regulators as Genascence prepares to advance into a Phase 2 trial to further explore clinical efficacy.

Dr. Annahita Keravala, Genascence's Chief Scientific Officer, highlighted the historical challenge of locally inhibiting IL-1 activity in joints over extended periods. GNSC-001 is pioneering in its ability to sustain therapeutic levels of IL-1Ra in the synovial fluid following a single dose, showcasing the potential of this gene therapy to target key inflammation mediators and slow disease progression in osteoarthritis. This development offers new hope for transformative treatment options for patients.

The DONATELLO clinical trial, a double-blind, placebo-controlled study, is designed to evaluate the safety and pharmacodynamics of a single intra-articular injection of GNSC-001 in patients with knee OA. Conducted across ten centers in the United States, the trial involved 67 participants. The first five groups of patients were randomized to receive GNSC-001 at doses of either 1x10¹² vg or 1x10¹³ vg, with some receiving a short course of oral steroids for immune-conditioning, while others received a placebo. An additional arm was later added, where participants received 1x10¹³ vg GNSC-001 combined with a brief three-day steroid course and a local steroid injection after providing pre-treatment synovial fluid samples.

The primary goal of the trial is to evaluate safety and tolerability, and the six-month data indicate that GNSC-001 meets these criteria, with no severe adverse events or treatment-related withdrawals reported. Common adverse events affecting the target knee included joint pain, swelling, and effusion. The secondary endpoints focused on IL-1Ra expression levels in the synovial fluid at six months, revealing that mean IL-1Ra expression reached and maintained target levels throughout the trial period. Importantly, immune-conditioning with short-term steroid use supported higher and more sustained IL-1Ra expression.

GNSC-001, a genetic medicine, aims to offer lasting inhibition of IL-1 signaling following a single joint injection. Recognized as a key player in OA pathogenesis, IL-1 contributes to inflammation, pain, and cartilage damage. By expressing an optimized form of IL-1Ra, GNSC-001 holds promise as a lasting solution for OA. Currently, GNSC-001 has received Fast Track Designation from the U.S. Food and Drug Administration.

Osteoarthritis of the knee is a widespread condition leading to disability, with over 30 million Americans affected. Characterized by cartilage degradation and structural changes in bone, OA causes pain and impaired joint function. The aging population and rising obesity rates are contributing to its prevalence. Despite the extensive use of NSAIDs, opioids, and steroid injections, no treatments currently exist that can alter or slow OA progression, underscoring the need for innovative solutions such as GNSC-001.