Eli Lilly has recently submitted a supplemental new drug application to the FDA to approve Cymbalta for the management of fibromyalgia, another milestone in a disease gaining prominence in the pharmaceutical industry. Datamonitor expects the fibromyalgia market to grow from under $400 million in 2006 to $2 billion by 2016, driven largely by pharmaceutical companies developing new therapies.

Common, yet underserved disease

Given the high unmet need and large patient population, fibromyalgia is one of the most keenly anticipated new central nervous system (CNS) markets in the pharmaceutical industry. Mainly affecting middle-aged women, fibromyalgia syndrome affects six million people in the US alone (about 2% of the population) and costs the US economy around $13 billion each year. This relatively common yet poorly understood syndrome is characterized by widespread muscle pain and fatigue and has historically been substantially underserved by both the medical profession and the pharmaceutical industry.

However, this began to change in June when Pfizer received US marketing approval for its epilepsy and neuropathic pain drug Lyrica to treat fibromyalgia symptoms. Currently, no other medications are licensed to treat this indication in the US, Japan or Europe. Traditionally, treatment has been a trial and error process, with physicians trying a variety of different unapproved medications to manage their patients' pain.

FDA approval of Lyrica came as large-scale Phase III clinical trials showed that Lyrica provides rapid and sustained improvements in fibromyalgia pain compared with placebo, and significant improvements in physical daily function. One of the drug's key strengths is its widely recognized effect as an analgesic (pain killer), which is greatly supported by its indication for neuropathic pain. Datamonitor estimates Lyrica fibromyalgia sales to grow to $641 million in 2016, making it the market leader at this time.

More effective drug treatments on the way

There are currently more than 20 drugs in development for the potential treatment of fibromyalgia. This number is expected to grow over the coming years as the predicted success of new drugs such as Lyrica, as well as a better-defined regulatory pathway and patient population, encourages other companies to consider investment.

Compounds in development consist mainly of centrally acting small molecule therapies. Although the cause of fibromyalgia is still unknown, the latest research suggests that fibromyalgia pain does not originate from trauma, inflammation, or nerve damage, but seems to be due to a disturbance in pain processing that originates in the brain.

Following closely behind Lyrica in terms of development is Eli Lilly's antidepressant Cymbalta. In August 2007, Lilly filed a supplemental new drug application to the FDA and Datamonitor expects Cymbalta to be approved for fibromyalgia treatment by 2008. With additional Phase III trials being conducted, Datamonitor predicts Forest/Cypress's milnacipran will be the third drug approved by the FDA for this indication in 2008. Several other candidates in late-stage development offer further promise for fibromyalgia patients, including sodium oxybate, lacosamide, rotigotine, reboxetine and radafaxine.

Of the mechanisms of therapeutic action targeted by pipeline companies, agents altering levels of dopamine are particularly promising, with a growing amount of literature suggesting a link between this neurotransmitter and fibromyalgia pathology. Two agents with these mechanisms are in late-stage clinical development: Schwarz/UCB's dopamine agonist rotigotine (Phase II) and GSK's noradrenaline and dopamine reuptake inhibitor radafaxine (Phase I).

Physician education and public awareness is key.

Historically, an accurate diagnosis of fibromyalgia is hindered by a lack of disease awareness and understanding among the general public and medical community. It is estimated over 50% of patients remain undiagnosed at any one time.

Given the heterogeneity of fibromyalgia symptoms, the average patient tends to see a number of physicians before correct diagnosis is made and appropriate treatment given. The common theme is insufficient physician education, delaying the referral process and leading to inappropriate treatment. Indeed, correct diagnosis can occur five to eight years after disease onset. As has been successful in the neuropathic pain market, Pfizer and other drug companies will do well to conduct physician education programs that improve understanding of diagnosis and treatment awareness among key prescribers.

Market will expand rapidly following drug approvals

With their extensive sales and marketing resources, Pfizer, Lilly and Forest will be instrumental in driving the growth in patient potential through extensive clinical education seminars and marketing campaigns. Estimated at $367 million in 2006 in the US and EU5, the fibromyalgia market is forecast to grow to $1.7 billion by 2016.

Following FDA approvals, there will be a dramatic rise in market value resulting from an upsurge in diagnosis and treatment rates. Commercial success of new treatments will encourage other companies to consider investment and will see the R&D pipeline expand over the coming years.

Importantly, the increase in industry investment is good news for the many patients unable to ease their condition with non-pharmacological solutions alone.

Related research:

• Stakeholder Opinions: Fibromyalgia - Potentially lucrative market soon to become reality

• Innovations in CNS: Novel therapeutics and future R&D strategies