One of the largest unmet needs in modern medicine is the effective treatment of osteoarthritis (OA)—a degenerative joint disease afflicting more than 30 million Americans and costing the healthcare system $459.5 billion in all-cause medical costs, according to a 2020 study in the Archives of Physical Medicine and Rehabilitation. “We see this as one of the biggest, if not the biggest, opportunities in biotech right now,” says CEO Thomas Chalberg, Ph.D. “OA is incredibly common, and there’s an enormous unmet need for a disease-modifying therapy.”
Enter Genascence, a biotech pioneer focused on using gene therapy to rewrite the OA treatment paradigm. The company’s lead candidate, GNSC-001, is a first-in-class gene therapy designed to inhibit interleukin-1 (IL-1), a cytokine central to OA’s cascade of inflammation, cartilage breakdown, and pain. Unlike transient biologic drugs, GNSC-001 uses a recombinant adeno-associated virus (AAV) to deliver an optimized interleukin-1 receptor antagonist (IL-1Ra) directly into the knee joint, potentially enabling sustained therapeutic protein expression for months—or even years—after a single injection. “All of the current treatments for osteoarthritis are palliative … By blocking IL‑1, can we actually change the course of the disease?” Chalberg asks.
Genascence’s Fast Track and phase 1b data
Genascence Corporation received Fast Track designation from the FDA for GNSC-001 on November 12, 2024. “I think we are one of the first major indications to go through the gene therapy division at the FDA,” Chalberg adds.
Recent six-month Phase 1b data revealed that GNSC-001 was well tolerated, with no serious adverse events and clear evidence of target IL-1Ra levels in synovial fluid. “We’re going to get the 12-month data sometime in Q2,” Chalberg notes, explaining that durability of effect is the next crucial question. An important finding involved immune conditioning (via oral and/or intra‑articular steroids), which significantly boosted therapy expression. Insights from this trial will inform the upcoming Phase 2 design, slated to include approximately 250 patients across multiple dose arms.
Scaling to meet demand
Implementing gene therapy in a widespread disease like OA requires a manufacturing approach that is both scalable and cost-efficient. As Chalberg puts it, “We need a four‑figure manufacturing cost in order to run a business, so that you can sell it for five figures … You can’t sell an osteoarthritis therapy for six or seven figures—it needs to be broadly accessible.”
Because GNSC-001 is administered locally rather than systemically, the vector dose is dramatically smaller than in many rare disease gene therapies. “It’s roughly one one-thousandth of the dose you’d see in a systemic gene therapy,” Chalberg explains. That lower dose drives down production costs, which helps Genascence pursue a feasible pricing model for millions of potential OA patients. “We’ve done a lot of work already to scale up for Phase 2, and then from there we plan to move to commercial scale, which will push down cost of goods even further,” Chalberg says.
By combining positive early clinical data, attention to immune conditioning, and a clear strategy to control manufacturing costs, Genascence may offer a blueprint for moving gene therapy beyond ultra‑rare indications. “We’ve basically taken gene therapy from the province of rare diseases and brought it into a major public health priority,” Chalberg said. “That’s the vision we’re executing on.”
Filed Under: Biotech, Cell & gene therapy
