TYSABRI is an integrin receptor antagonist indicated for treatment of:
Multiple Sclerosis (MS)
As monotherapy for the treatment of patients with relapsing forms of multiple sclerosis to delay the accumulation of physical disability and reduce the frequency of clinical exacerbations. TYSABRI is generally recommended for patients who have had an inadequate response to, or are unable to tolerate, an alternate MS therapy.
Crohn’s Disease (CD)
Inducing and maintaining clinical response and remission in adult patients with moderately to severely active Crohn’s disease with evidence of inflammation who have had an inadequate response to, or are unable to tolerate, conventional CD therapies and inhibitors of TNF-α.
When first launched, Tysabri (natalizumab) was broadly considered the biggest breakthrough in MS treatment since the introduction of interferons in the 1990s.
“Tysabri represents a significant advance in MS treatment, offering real hope of delaying the progression of disability and reducing the frequency of relapses.” - Professor Gavin Giovannoni, The Royal London Hospital, 2004.
However, at the time of the relaunch no test was available yet to predict the risk of PML in individual patients.
Deliberately high access barriers severely impacted treated patient numbers and, consequently, Biogen IDEC/Elan's revenues from Tysabri.
FDA Drug Safety Communication: New risk factor for PML associated with Tysabri.
The risk factors are:
The drug label for Tysabri has been revised to reflect this updated information including a table estimating the rate of PML stratified by the three known risk factors:
Table: Estimated PML Incidence Stratified by Risk Factor
|Anti-JCV Antibody Positive*||Anti-JCV Antibody Positive*|
|Tysabri Exposure||No Prior Immunosuppressant Use||Prior Immunosuppressant Use|
It was thought that in combination with clinical risk factors, the JCV test could identify patients at high risk of PML.
The test ordering process appears to be well managed but the need to send samples to a central laboratory may still create barriers to maximal Stratify JCV uptake.
Biogen Idec and Elan Submit Applications for First-Line Use of TYSABRI in anti-JCV Antibody Negative Patients with MS
- Marketing Applications Supported by Risk Stratification Data -
WESTON, Mass. & DUBLIN--(BUSINESS WIRE)--Jan. 16, 2013-- Today Biogen Idec (NASDAQ: BIIB) and Elan Corporation, plc (NYSE: ELN) announced that they have submitted applications to the U.S. Food and Drug Administration (FDA) and European Medicines Agency (EMA) requesting updates to the TYSABRI® (natalizumab) labels. The applications request an expanded indication that would include first-line use for people living with certain relapsing forms of multiple sclerosis (MS) who have tested negative for antibodies to the JC virus (JCV). A formal assessment of both applications is ongoing.
These submissions are supported by risk stratification data and a risk algorithm that enables physicians and individuals living with MS to make informed decisions when considering treatment with TYSABRI. If approved, a first-line label will allow all appropriate anti-JCV antibody negative patients to consider TYSABRI early in the course of treatment, regardless of the level of disease activity or prior treatment history. TYSABRI is a highly efficacious treatment that has been shown to slow disability progression by 42 – 54 percent and reduce annualized relapse rates by 68 percent.
If granted, first line indication would expand the eligible patient population from 10 to 12 per cent to over 40 per cent of all MS patients.
Investment in 'safety Dx' is likely to earn a substantial return on investment.
Since immunodeficiency causes JCV to progress to PML, a confirmed JCV infection is a general contraindication to immunosuppressant drugs.
Boxed warnings related to PML / JCV infections have been added to the label of several widely used novel drugs that act as immunosuppressants:
There is an opportunity for Dx owners to expand the use of JCV testing to other commonly prescribed immunosuppressant drugs.
As the June 2013 study suggests, a JCV test may not be sufficient.
Will MRI screening become the complement Dx to JCV testing in monitoring patients?