Latest research on Tysabri

Humanized IgG4k monoclonal antibody produced in murine myeloma cells. Natalizumab contains human framework regions and the complementarity-determining regions of a murine antibody that binds to a4-integrin. Natalizumab was voluntarily withdrawn from U.S. market because of risk of Progressive multifocal leukoencephalopathy (PML). It was returned to market July, 2006.

Latest findings

The 10-year, prospective Tysabri (natalizumab) Observational Program (TOP; NCT00493298) was established to report the long-term safety and efficacy of natalizumab for the treatment of RRMS in a clinical practice setting. [source, 2016]
Tysabri (natalizumab) is used to treat adults with relapsing remitting multiple sclerosis. [source, 2016]
Since MS is a disease of a typically young patient population with usually no reduced lifespan, and since there are therapeutic alternatives with an established safety profile, Tysabri should be clearly restricted to patients that are really in need of such a therapy. [source, 2016]
In this example, there is a suspicion that Tysabri might be negative for a subgroup. [source, 2016]
Within the new drugs, the natalizumab (Tysabri, Biogen, Cambridge, MA) has been shown to have a large effect in reducing disease activity. [source, 2015]
Several studies, for instance the TOP (Tysabri Observational Program [16]), confirmed the natalizumab driven overall safety profile, low relapse rate and stabilized disability levels in treated patients over 5 years. [source, 2015]
Of the thirty-three RR-MS patients, fourteen patients were on interferon-β1a (Avonex, Biogen Idec, Cambridge, MA USA), ten patients were on interferon-β1a (Rebif, Merck Serono, Rockland, MA, USA), seven patients were on interferon-β1a (Betaseron, Bayer HealthCare Pharmaceuticals, Montville, NJ, USA), ten patients were on glatiramer acetate (Copaxone, Teva pharmaceuticals, North Wales, PA, USA) and one patient was on natalizumab (Tysabri, Biogen Idec, Cambridge, MA USA). [source, 2015]
In 2006, natalizumab was reintroduced into the US market and released in the European Union, together with a Global Risk Managment Plan, to be carried out mandatorily in the US (TOUCH®: Tysabri Outreach: Unified Commitment to Health) and voluntary in the remaining parts of the world (TYGRIS®: Tysabri Global Observation Program in Safety). [source, 2015]
Recently, two phase IV studies evaluated the long-term safety and efficacy of natalizumab therapy (Safety of Tysabri Redosing and Treatment [STRATA] MS;48 Tysabri Observational Program [TOP]). [source, 2015]
The STRATA MS study enrolled patients from the pivotal phase III trials (AFFIRM,22 SENTINEL,23 Glatiramer acetate and Natalizumab Combination Evaluation [GLANCE],40 and Study of Tysabri Against Rebif in relapsing multiple Sclerosis [STARS] EudraCT number: 2004-004130-14) after natalizumab dosing was suspended due to the occurrence of three PML cases. [source, 2015]