More MS news articles for August 2002

Multiple Sclerosis: the search for a vaccine continues

02 Aug 2002

There are approximately 250,000 to 350,000 diagnosed cases of multiple sclerosis in the US, yet it is estimated that the actual number of Americans with MS may be even higher. As a new approach to the treatment of MS, vaccines have the potential to be both efficacious and cost effective. But can a vaccine be developed as a viable treatment for MS?

Experts anticipate an increase in the R&D in the multiple sclerosis market with a lack of effective treatments for this progressive and chronic disease currently available. Vaccines offer an innovative therapeutic approach and may result in an expanded CNS market, but may also pose a threat to currently available drugs.

Untapped market

Viable treatments for MS represent a great-unmet need in the healthcare market thereby guaranteeing a premium price for efficacious vaccines. Current vaccines only offer the possibility of halting or reducing the progression of the disease. The demand for treatment will also increase as diagnosis measures improve and more cases of MS are identified.

In addition, the high socioeconomic costs associated with MS will also contribute to a vaccine achieving a high price premium. Being one of the most common chronic diseases, MS is a large cost burden to both society and to the suffering patients.

For example, the cost of MS per patient per year has been estimated to be $14,000 in both France and Germany. Sufferers often have to spend long periods away from work, with lost tax revenues and loss of income both for patient and their careers.

Need for proof

In the long-term, patients are forced to stop working altogether, creating even higher social costs. It is estimated that 50-80% of MS sufferers are unemployed after 10 years of disease progression

A vaccine that is able to halt the progression of MS or significantly reduce progression compared to current therapies can command a price premium if it can demonstrate both clinical and cost benefits.

High demand for a clinically effective product is driven by the insufficiencies of current therapies and the high public awareness about MS. This public demand, as well as the potential cost benefit of a vaccine will be the key to vaccines achieving high price premiums.

Limited R&D progress

There have been a number of trials investigating T-cell vaccination including bovine myelin reactive irradiated T-cell lines, Myelin basic proteins (MBP)-reactive T-cells and TCR-V beta family activate T-cells. Other trials have investigated the use of antigen peptides as vaccines, such as the TCRV beta 6 peptide.

These vaccine mechanisms have the potential to prevent the progression of MS once the disease has been diagnosed. However, they will not prevent the onset of MS, though if used early in the treatment of MS they could be an important therapy option.

In order to prevent the development of MS, a deeper understanding of the initiating causes of MS are required. While the initial cause is still unclear, generic inheritance and viral infections have been suggested as causative factors of MS.

There are potentially two types of MS vaccines, prophylactic vaccines and therapeutic vaccines. To date, it is the later type of vaccine that is being developed. It is unlikely that a prophylactic vaccine will be developed in the near future until the causes of MS have been elucidated.

Still work to be done

At present the MS market is dominated by a few key treatments. Biogen's monopoly over the US market was only recently broken when Serono managed to prove that Rebif was more effective in treating relapsing remitting multiple sclerosis (RRMS). Rebif will provide significant competition to the other main MS treatments of Avonex, Betaseron and Copaxone.

While these drugs have demonstrated the ability to reduce the progression of the disease and associated symptoms, none have demonstrated the ability to halt MS leaving a large gap in the market for such a product. As a poorer alternative to stopping progression, demonstrating a reduction in progression, is now key to the uptake of these products.

Other than the existing competition, the potential success of neurology vaccines is also being hindered by potential dangers. With the recent discontinuation of Elan's Alzheimer's disease (AD) vaccine, due to side effects, long-term safety remains a large concern for neurology vaccines.

There is the risk that MS antibodies crossing the blood brain barrier may trigger an unwanted immune response. Therefore, as with AD vaccines, robust phase IV trials evaluating the long-term safety of an MS vaccine will be important in its development.

Vaccine not the only answer

While there is a large potential for MS vaccines, pipeline products such as immunosuppressants and monoclonal antibodies are potential competitors to the vaccine market.

Monoclonal antibodies are able to treat MS because of their ability to block the entry of destructive immune cells into the brain and spinal cord. The aim is therefore to reduce the severity and duration of the MS attack.

Immunosuppressants help shorten attacks or slow the progression of MS by suppressing the immune system and limiting the myelin damage that can be caused by an autoimmune response. Incidence of toxic side effects are high, however, the launch of Novantrone in 2001 demonstrates that drugs of this class have the potential to reach the market.

Though monoclonal antibodies, immunosuppressants and vaccines work on the immune system, the former two have the disadvantage of not being able to induce immune memory, which means there duration of action will be shorter than that of a vaccine.

Due to the significant need for effective treatments of neurology diseases, this market is particularly open to innovative products. Uptake of the first neurology vaccines to enter the market will be determined by innovation rather than marketing, which is generally the case in mature markets with little unmet need.

In order to fully maximize MS vaccine uptake, these products will have to be launched before competitors that can offer similar properties. The establishment of such products will not only reduce the novelty of vaccines but will increase the marketing required for their uptake.

In addition, the cost benefit offered by monoclonal antibodies and neuroprotectants are likely to be greater than that offered by current MS therapies, and will therefore reduce the price premium that a MS vaccine can command.

© 2002, Datamonitor plc