FDA approves Zinbryta to treat relapsing forms of multiple sclerosis

Zinbryta is a humanized IgG1 monoclonal antibody that selectively binds to the high-affinity interleukin-2 (IL-2) receptor subunit (CD25), a protein that is over-expressed on T cells that become abnormally activated in MS.

The efficacy of Zinbryta was tested in two clinical trials. The first trial was a comparison between the effects of Avonex and Zinbryta in 1,841 study participants over the course of 144 weeks.

It was demonstrated that patients who took Zinbryta experienced fewer MS relapses than those taking Avonex.

In other trial of 412 subjects, Zinbryta was compared with placebo for 52 weeks and results demonstrated that patients on Zinbryta experienced fewer relapses.

Biogen executive vice president and chief medical officer Alfred Sandrock said: "Zinbryta is the first once-monthly, self-administered treatment in MS, and it demonstrated superior efficacy over a widely used interferon.

"Clinical data showed Zinbryta significantly reduced relapses and brain lesions for up to three years compared to Avonex (interferon beta-1a) intramuscular injection, and has a positive benefit-risk profile with monthly patient monitoring."

Besides the approval, Zinbryta has shown adverse effects on the human body such as hepatic injury and it is mentioned on its packaging.

Due to the intensity of the adverse effect profile, the drug has a boxed warning on its label, and is available only via a restricted distribution program under a Risk Evaluation and Mitigation Strategy.

The patients taking the drug are urged to do liver functions tests (LFTs) on a monthly basis prior to starting therapy.

Image: The recommended dosage of Zinbryta is 150 mg, self-administered subcutaneously on a monthly basis. Photo: courtesy of Business Wire.