How Gene Therapy Could Transform Osteoarthritis Treatment

At a recent webinar organised by the International Cartilage Regeneration and Joint Preservation Society (ICRS) in collaboration with Pacira Biosciences exploring how gene therapy is transforming osteoarthritis treatment, Monica Pianella, Director of Regulatory Affairs at Boyds, joined Dr Kilian Guse, Prof Christopher Evans, and Prof Yves Henrotin to discuss the scientific progress, translational challenges and regulatory considerations shaping this emerging field.

Their discussion reinforced a clear and important point: despite the scale of the unmet need in osteoarthritis, current treatment options remain focused largely on symptom control. Gene therapy, by contrast, may offer a route towards more durable, targeted intervention by addressing the biology of the disease itself.

A significant unmet need in osteoarthritis

Osteoarthritis affects millions of people worldwide and continues to place a substantial burden on patients, healthcare systems and society more broadly. Pain, stiffness and reduced mobility can have a major impact on quality of life, yet available pharmacological treatments are still primarily aimed at short-term symptom relief.

While these approaches may provide benefit for some patients, they do not alter the underlying disease process. There is currently no approved disease-modifying therapy for osteoarthritis, and patient dissatisfaction with existing treatment options remains high (Vitaloni et al, 2020). This is one of the key reasons why novel approaches such as gene therapy are attracting increasing interest.

A different therapeutic approach

Gene therapy offers the potential to move beyond repeated administration of conventional treatments by enabling sustained local expression of therapeutic proteins within the affected joint.

In osteoarthritis, much of the focus is on targeting inflammatory pathways that contribute to cartilage degradation, structural damage and pain. One pathway of particular interest is interleukin-1 (IL-1), which is recognised as a key driver of chronic inflammation and disease progression in osteoarthritis. Delivering genes that support local production of interleukin-1 receptor antagonist (IL-1Ra), the body’s natural inhibitor of this pathway, may provide a way to reduce inflammation and potentially slow progression in a more durable and targeted way.

This has important implications. Rather than relying on treatments that need frequent repeat dosing and primarily manage symptoms, gene therapy may offer the possibility of longer-lasting biological activity with the potential to influence disease mechanisms more directly.

Delivery remains central to success

As with all gene therapies, the success of the approach depends heavily on effective delivery. Genetic material must reach the right target cells in sufficient amounts, remain active for an appropriate duration and do so with an acceptable safety profile.

Different vector platforms are being explored to achieve this. These include adenoviral (AdV) and adeno-associated viral (AAV) vectors, each with distinct characteristics in terms of payload capacity, duration of expression, tissue tropism, immunogenicity and manufacturability.

The webinar highlighted encouraging progress across different vector approaches, with evidence that local administration into the joint can support sustained expression of therapeutic proteins. This is particularly relevant in osteoarthritis, where a localised treatment strategy may help maximise effect within the joint while limiting systemic exposure.

Translational progress is beginning to emerge

One of the most promising aspects of the field is that development is moving beyond theoretical potential and into early translational and clinical evidence.

Non-clinical studies have shown effective transduction of relevant joint tissues, including synovial tissue and, in some cases, chondrocytes, along with long-term expression in animal models. These studies have also generated encouraging signals in terms of reduced inflammation, improved cartilage preservation and functional benefit (Nixon et al, 2018; Watson-Levings et al, 2022).

Early clinical studies discussed in the webinar also suggest that intra-articular gene therapy approaches may be feasible and generally well tolerated. Initial findings reported favourable safety profiles, evidence of local transgene expression and encouraging trends in pain and function outcomes over extended follow-up periods (NCT04119687, NCT02790723, NCT05835895).

Although these are still early-stage data and larger controlled studies will be needed to confirm efficacy, they represent an important step forward. In a condition with few therapeutic innovations that target the biology of disease, even early evidence of durable local activity is notable.

Regulatory expectations are appropriately high

From a regulatory perspective, gene therapies for osteoarthritis sit within a demanding development environment.

In both the European Union (EU) and the United States (US), gene therapies are regulated as biologics. Within the EU, they belong to the category of Advanced Therapy Medicinal Products (ATMPs) and are assigned to clearly defined sub‑classes. In contrast, the US Food and Drug Administration (FDA) addresses the nuances between cell and gene therapies primarily through guidance documents, rather than through a distinct product classification framework. In both regions, developers must address a broad range of requirements covering non-clinical development, quality and manufacturing, clinical trial design, long-term follow-up and, where applicable, biosafety or genetically modified organism (GMO)-related approvals.

A critical point is that osteoarthritis is not a life-threatening condition. As a result, regulators will generally expect a tighter risk-benefit balance than for gene therapies developed for severe or fatal diseases. This raises the evidentiary bar and has practical implications across the development programme.

Developers need to think carefully about biodistribution, vector shedding, immunogenicity, long-term persistence and demonstration of long-lasting effect, potency, dose selection and the clinical relevance of their non-clinical models. Clinical trial design also requires particular care, especially when it comes to patient selection, concomitant therapies and managing confounding factors, and long-term safety monitoring.

CMC strategy will be a major differentiator

Chemistry, manufacturing and controls (CMC) remains one of the most important challenges in gene therapy development, and this is likely to be especially true for osteoarthritis.

Unlike gene therapies which target rare diseases and relatively small patient populations, osteoarthritis is a highly prevalent condition. Any successful therapy will therefore need a manufacturing strategy capable of supporting larger-scale supply at a commercially viable cost.

That makes early alignment across process development, analytical development, non-clinical studies and clinical planning particularly important. Significant manufacturing changes made later in development can lead to the need for comparability exercises or additional bridging data, introducing delay, cost and regulatory complexity.

For developers in this space, CMC strategy is not simply a technical consideration. It is central to the overall viability of the programme.

Early regulatory engagement is essential

Given the novelty of the science and the complexity of the development pathway, early engagement with regulatory authorities is likely to be critical.

Scientific advice can help clarify expectations around study design, potency strategy, non-clinical package requirements, long-term follow-up and patient population selection. This can be particularly valuable in a field where precedent is still limited and where product-specific considerations are likely to shape the development path.

In Europe, sponsors also need to plan carefully for any GMO-related approvals required for initiation of clinical trials with gene therapies, as these processes can be lengthy and may affect site start-up timelines. Factoring these requirements into the development plan from the outset can help avoid unnecessary delays. However, efforts are being made to streamline GMO approval processes in the EU with the upcoming EU Pharmaceutical legislation and EU Biotech Act for well-established GMO-containing ATMP classes, ultimately helping bring these innovative and promising therapies to patients with less administrative delays.

Looking ahead

Gene therapy for osteoarthritis remains an emerging area, but momentum is clearly building. Advances in vector design, a stronger understanding of disease biology, encouraging early clinical findings and an evolving regulatory framework are all contributing to progress.

There is still considerable work ahead. Larger and well-controlled studies will be needed to confirm clinical benefit. Development programmes will need to demonstrate an appropriate risk-benefit profile for a non-life-threatening condition. Manufacturing approaches will need to support scalability and consistency. Regulatory strategies will need to be robust, pragmatic and forward-looking.

Even so, the field is moving in a promising direction. For patients living with osteoarthritis, and for developers working to bring more effective treatments forward, gene therapy represents an important area of innovation with genuine potential to reshape future disease management.

To watch the webinar, a recording is available on YouTube: https://youtu.be/SthRvajqfcc?si=JDBLx9QFG-ayHlFO 

References

NCT04119687 Study to Evaluate the Safety and Tolerability of FX201 in Patients with Osteoarthritis of the Knee

NCT02790723 Safety of Intra-Articular Sc-rAAV2.5IL-1Ra in Subjects With Moderate Knee OA (AAVIL-1Ra)

NCT05835895 Safety and Pharmacodynamics of GNSC-001 Intra-articular Injection for Knee Osteoarthritis (DONATELLO)

Nixon AJ, Grol MW, Lang HM, et al. Disease-Modifying Osteoarthritis Treatment With Interleukin-1 Receptor Antagonist Gene Therapy in Small and Large Animal Models. Arthritis Rheumatol. 2018;70(11):1757-1768

Vitaloni M, Botto-van Bemden A, Sciortino R, et al. A patients’ view of OA: the Global Osteoarthritis Patient Perception Survey (GOAPPS), a pilot study. BMC Musculoskelet Disord. 2020;21(1):727. Published 2020 Nov 7

Watson-Levings RS, Palmer GD, Levings PP, Dacanay EA, Evans CH, Ghivizzani SC. Gene Therapy in Orthopaedics: Progress and Challenges in Pre-Clinical Development and Translation. Front Bioeng Biotechnol. 2022;10:901317. Published 2022 Jun 28.

How Boyds can help

For companies developing gene therapies and other advanced therapies, success depends not only on scientific innovation but also on a clear and well-structured regulatory strategy.

Boyds supports developers across the full product lifecycle, from early regulatory planning and non-clinical strategy through to clinical development, ATMP classification, CMC support and agency interactions. In complex and fast-evolving areas such as gene therapy for osteoarthritis, early strategic input can help reduce development risk, strengthen regulatory positioning and support more efficient progression towards the clinic and beyond.