Personalizing for Better Products

Pharmaceutical drug development is becoming more and more expensive, with a high incidence of products failing late-stage trials. Governments and healthcare payers are demanding medicines that offer a balance of benefit and cost. Could personalized medicines and diagnostics offer a solution to both?

In April 2011, the EMA’s Committee for Medicinal Products for Human Use recommended a label update for Biogen and Elan’s multiple sclerosis drug Tysabri (natalizumab). Late in January 2012, the FDA also approved the label change in the US.

Although touted as an effective treatment, Tysabri has also been associated with the risk of developing a serious and, often fatal, brain infection called progressive multifocal leukoencephalopathy (PML). The new label identifies that a certain antibody status (presence of anti-JCV antibodies) is a risk factor for developing PML. A test to detect these antibodies can identify at-risk patients, which is a development that marks a step towards personalised medicine - matching the right treatments with the right patients to maximize therapeutic effect.

In their press statement, Biogen and Elan added that Quest Diagnostics will be producing the STRATIFY JCV Antibody ELISA testing service in the US, which is the first blood test authorised by the FDA for the qualitative detection of JCV antibodies. When used with other clinical data from the patient, the test can help healthcare providers determine the risk for developing PML. Such testing has already been used in Europe since the label was updated last year.

Biogen and Elan have also identified two other PML risk factors: over two years of treatment with Tysabri, and previous treatment with medicines known to weaken the immune system.

Tysabri has had a rickety life. It was voluntarily withdrawn from the US market in 2005 because of concerns over PML, but relaunched in 2006 with a black box warning and a strict monitoring plan. In Europe, Tysabri was approved in 2006 but has been under close scrutiny by the EMA. The EMA has also kept a tight watch and finalised a review of the medicine in January 2010, concluding that the benefits of the medicine outweigh the risks.

As well as improving the safety of patients, the new label could also help to boost Tysabri sales. According to an article by Bloomberg, financial analysts have forecast that Tysabri could see its global sales grow to as much as $3 billion by 2016. Without the label change, the drug may only have seen sales of $1.5 to 2 billion.

The JCV diagnostic test is a good example of how pharma companies can improve their medicines. All drugs, unfortunately, have side effects but a lot can be gained by understanding how those effects occur-and in which patients. Biogen and Elan are not the only companies making efforts to personalise their medicines. As was well publicised last year, Sanofi’s Avastin had its breast cancer indication removed in the US. However, Sanofi is looking hard at the drug in order to evaluate a potential biomarker that could help identify which people might derive more substantial benefit from the drug. Interestingly, Avastin was in the headlines yesterday with Bloomberg running a news piece about how Avastin studies have pointed to potential benefits when used in early-stage breast cancer.

No doubt there is more to come in the world of biomarkers, diagnostics and personalized treatments.