Tuberculosis: new drug opportunities in an old market

The tuberculosis market is historically one of low value and limited growth. Consequently, the commercial incentive to develop or market drugs has been restricted and the product pipeline has dried up. However, a recent resurgence in key European markets and the continued health problems that the disease poses in poorer geographical regions has sparked renewed commercial interest.

Tuberculosis (TB) has been a considerable source of morbidity and mortality for thousands of years. However, the introduction of effective antibiotics and a dramatic improvement in sanitation, diet and a reduction in overcrowded living conditions in the developed world, has led to a significant decline in TB incidence.

A resurgent market

Expert consensus suggested that the disease would be totally eradicated by the end of the 21st century. However, TB has recently re-emerged as a huge threat to global populations due to two key factors: the HIV pandemic and the emergence of multi drug resistant strains of TB.

The TB market has remained static over the last 45 years, with no new drug class launches since 1966. This market sector has traditionally been associated with poor return on investment, because the disease was predominantly limited to the developing regions of the world.

However, the resurgence of TB infection in the developed world has renewed the demand for effective prophylactic and therapeutic treatment, as well as a need for improved diagnostic kits. There is, therefore, significant potential for companies considering investment in this market.

Market opportunities

There are numerous opportunities within the TB market, with improvements required in the diagnosis, treatment and prevention of the disease. An increasing patient population is beginning to drive growth of a previously stagnant market, and this could represent an opportune time for companies to capitalize on this market potential.

Long-term combination therapy with antibiotics is the mainstay of TB treatment. Combination therapy prevents the development of resistance and has proved to be a highly effective means of fighting the disease, combining drugs with different modes of action that target different attributes of the bacilli.

However, there has only been limited activity within the TB treatment market since the last major drug, rifampicin, was launched in 1966. The lack of interest has been attributed to the apparently curative nature of available TB treatments and the conception of TB as a "poor disease".

As such, the potential return on investment is perceived to be low within this market, limiting the incentive for companies to get involved. However, the Global Alliance for TB development estimates the TB market size will grow from around $440 million in 2000, to almost $700 million by 2010, and although this represents a comparatively small market size, careful product placement and market strategies could drive a more significant growth in the market.

Unmet needs

Currently available treatments are associated with a wide range of side effects that occur in 3-5% of patients. For example, side-effects associated with isoniazid products range from nausea, vomiting, constipation and fever to convulsions, psychotic episodes and hepatitis.

Combining antibiotics can lead to more severe complications, and at least five patients have died from liver failure after taking pyrazinamide and rifampin concurrently.

Compliance with available TB treatments is also relatively low, as a result of the high incidence of side effects and the length and complexity of treatments, and many patients who begin therapy fail to complete it, fueling the emergence and spread of multi drug resistant TB.

The pipeline alliance

The recognized need for new TB treatments led to the conception of the Global Alliance for TB Drug Development, a non-profit organization, in 2000. This alliance aims to draw on resources from public and private sectors in order to accelerate R&D of new drugs.

Newly developed drugs will then be provided through the alliance at affordable prices to countries in the developing world. The first partnership involving the Global Alliance for TB Drug Development arose in February 2002, involving Chiron and it's anti-TB compound PA-824 currently in preclinical development.

Chiron granted the Global Alliance for TB Drug Development an exclusive worldwide license to develop PA-824 and its related compounds as an anti-TB treatment. Under the agreement, no royalties will be granted to Chiron, but a grant-back option was included in the license that would allow Chiron to manufacture and market the product in the developed world. The agreement provides Chiron with a low-risk option to enter the TB treatment market.

A license to print money?

Despite the efforts of the Global Alliance for TB Development, there are still less than 10 products in development for the treatment of TB, all of which are in early stage research. The lack of activity in the TB market has created a high level of unmet need associated with current treatment options.

Additionally, the lack of new products and loss of antibiotic patents have led to the market becoming highly genericized and of relatively low value. However, competition within the market is relatively limited meaning that companies that do develop more efficacious products are likely to be able to capitalize on the full patient potential of this market.

If you found this article useful, you may be interested in Datamonitor's Executive Report, "Tuberculosis: Extracting Value From a Stagnant Market"

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