Tysabri Seen as Superior to IFN-β in Preventing Relapses, Easing Disability in Small Study

Tysabri (natalizumab) was found to be superior to interferon beta (IFN-β) in a small, 12-month study with relapsing-remitting multiple sclerosis (RRMS) patients, significantly decreasing their disability levels, its researchers report.

A vast majority — 90 percent — of Tysabri-treated patients experienced no relapses during the study period, while none of those taking IFN-β were relapse-free.

The study, “The Effect of Natalizumab on Disability Score and Relapse Rate of Multiple Sclerosis Patients: a Prospective Cohort Study,” conducted at a single site in Iran, was published in the journal Clinical and Translational Medicine.

Tysabri is a humanized monoclonal antibody the binds to the α4β1-integrin molecule, preventing harmful immune T-cells from crossing the blood-brain barrier (which protects the brain) and damaging nerve cells. IFN-β is an immunomodulator that reduces the inflammation in the central nervous system that also damages nerve cells in MS patients. Both have been approved to treat relapsing forms of MS.

Researchers compared the clinical effectiveness of Tysabri (marketed by Biogen; monthly intravenous infusion of 300 mg) with that of IFN-β (intramuscular injections of 20 μg, three times a week) in RRMS patients being treated at a hospital in Hamadan.

CinnoVex (marketed by CinnaGen, based in Tehran) was the IFN-β-1a therapy used in this study. In the United States, IFN-β-1a is marketed as Avonex, Plegridy, and Rebif.

In total, 20 RRMS patients (mean age, 33 ) received Tysabri, and 30 patients (mean age, 36.83) were given IFN-β. Patients were followed for 12 months during 2015–16, and their disability scores (assessed through the expanded disability status scale, EDSS) and clinical signs were evaluated monthly.

All patients had been treated with IFN-β, but experienced relapses during the prior year despite treatment. Patients in the Tysabri group stopped using IFN-β and switched to Tysabri; those in the IFN-β group continued treatment with this therapy.

Researchers found that although Tysabri-treated patients had higher EDSS scores than their IFN-β-treated counterparts at the study’s start (months 1–4), these scores had lowered significantly as it concluded (months 10–12) compared to IFN-β-treated patients.  From study start to month 12, the mean EDSS score decreased to 3.98 from 5.45 in Tysabri-treated patients, and increased to 5.10 from 4.52 in the IFN-β group.

The higher a patient’s EDSS score, the worse is his or her disability level.

No MS relapses were reported in 90 percent of Tysabri-treated patients during the 12-month study period; the remaining two people in this group (10%) experienced one relapse. Relapses were reported in all IFN-β-treated patients, with 36.6% experiencing one relapse and 63.3% two relapses.

“EDSS scores showed a significant decrease in 80% of natalizumab-treated patients,” and the “number of relapses was significantly lower in natalizumab-treated patients compared with the control group,” the researchers wrote.

Tysabri, they concluded, is effective at lowering relapse rates and disability scores in MS patients.

The researchers added that the results provide further evidence of Tysabri’s effectiveness as a single second-line treatment for RRMS patients.