Osteoarthritis: The silent burden

Osteoarthritis (OA) is a degeneration of the joints characterized by progressive destruction of articular cartilage and articular structures. It is a complex process which involves multiple changes in joint structure and turnover and it is the leading cause of disability in the US , and is estimated to be the eighth most common cause of disability worldwide. In a recent report*, independent market analyst Datamonitor (DTM.L) estimates that 89 million adults in the seven major pharmaceutical markets** have some form of symptomatic osteoarthritis. Due to the current widespread nature of the condition, the World Health Organization (WHO) has declared the current decade (2000-2010) the ‘Bone and Joint Decade’.

Movement limited
High unmet need and a large patient population are the key drivers towards research and innovation in osteoarthritis. The WHO estimates that 10% of men and 18% of women over 60 years of age have symptomatic OA. It also estimates that 80% of those with OA have limitations in movement and 25% cannot perform the major daily activities of life. Yet this debilitating and widespread condition has no cure and is most commonly treated with simple analgesics and anti-inflammatories. General awareness is low and, rightly or wrongly, many people consider this condition to be simply a result of aging. These ageist perceptions and low awareness provide a substantial negative impact on the market, says Datamonitor healthcare senior analyst Clare Churchill. “The fact that the oldest, least socially-visible section of the population is most affected does go some way in explaining the counter-intuitive differences between low general awareness and high prevalence,” she says.

Treatment requires paradigm shift
Treatment currently centres on palliative care including non steroidal anti-inflammatory drugs (NSAIDs), but in the light of recent controversies with Vioxx and Bextra in the Cox-2 class of pain killers, demand for alternatives exists and a paradigm shift in the way osteoarthritis is treated is needed. Other effective treatment options are available- not least lifestyle factors- but opioids and alternative therapies are also are battling against their own preconceptions.

As OA patients suffer from an incurable and often inadequately-treated condition, they tend to be particularly attracted to alternative medicine as a means to reduce their pain, Churchill says. “One of the reasons suggested for the success of physiotherapy and certain acupuncture treatments is the beneficial impact of sufficient time spent communicating with the patient, a luxury that many physicians cannot afford.”

The treatment of OA has historically been symptomatic, but increasing numbers of drugs are being tested for a disease-modifying effect. The blockbuster success of disease-modifying treatments for rheumatoid arthritis, such as the TNF-inhibitors, and recent side-effect issues surrounding NSAIDs are the driving forces behind this trend. However, evidence of successful disease modification in OA is limited and the trials that have been conducted have not shown particularly impressive results.

Clinical trials for disease modifying and symptomatic products for osteoarthritis require careful design. However, the optimum design is not yet decided among experts. Advances in imaging offer promise, but interpretation of results must be unified and though the identification of biomarkers is progressing, they are often difficult to utilize.

Unmet needs and challenges abound
Datamonitor has interviewed a range of OA professionals, including scientists involved in laboratory research, patient advocates and opinion-leading physicians. The range of views received agree on one key point: that OA awareness is not as high as it should be, Churchill says. “This view was most strongly expressed by patient advocates, but is echoed in comments regarding a lack of specific arthritis research funds in certain countries, and a lack of musculoskeletal training for general practitioners.”

Evaluating imaging and new lab tests to detect OA early, so that treatment can begin before significant damage occurs is a key challenge faced by the rheumatology community. Advances in magnetic resonance imaging (MRI) and ultrasonography have begun to show internal details of articular cartilage that correspond with histologic zones.

MRI technology should reduce the number of patients needed in clinical trials, improve retention of these patients, and reduce the overall costs and the length of clinical trials of treatment response to disease modifying OA drugs (DMOADs). However, the cost of MRI can be a prohibitive factor in already expensive clinical trials.

New treatments must focus on the impact of OA on patients, and physician opinion indicates that a multi-disciplinary approach to OA treatment is required; involving nurses, physiotherapists and other healthcare professionals in the treatment. Factors such as the important effect of fatigue on arthritis patients have been highlighted by such collaborations.

The issue of relative lack of awareness of OA must be addressed to make it a higher priority for government research funding, which in turn aids the development of treatments, Churchill says. “OA offers a very attractive commercial target in terms of patient potential, and the explosion in new disease modifying drugs in rheumatoid arthritis has highlighted the possibilities for OA. However, controversy in the Cox-2 class, preconceptions about alternative treatments and even debate around the definition of OA make this a more difficult market to break into than first thought.”

Notes

*Stakeholder Opinions: Osteoarthritis - Preconceptions Damage Awareness and Treatments

**The seven major pharmaceutical markets are the UK , US, France , Germany , Italy , Japan and Spain .

Datamonitor’s (DTM.L) report, Stakeholder Opinions: Osteoarthritis - Preconceptions Damage Awareness and Treatments, looks at key issues in osteoarthritis therapy, including unmet needs, current treatment controversies, advancements in patient involvement and clinical trial end-points, and novel therapies in the developmental pipeline.

(14/6/06)