The American Food & Drug Administration (FDA) has just added an additional treatment option to the armamentarium of drugs to fight MS by approving Daclizumab (Zinbryta) for the treatment of adults with relapsing forms of MS. Daclizumab (Zinbryta) is a long-acting injection that is self-administered by the
patient monthly. Daclizumab (Zinbryta) is a therapeutic humanized monoclonal antibody and works by binding to CD25, the alpha subunit of the IL-2 receptor of T-cells. Previously, Daclizumab was already FDA-approved under the trade name Zenapax to prevent rejection in organ transplantation, especially in kidney transplants.
According to FDA, the effectiveness of Zinbryta was shown in two clinical trials. One trial compared Daclizumab (Zinbryta) and Avonex in 1,841 participants who were studied for 144 weeks. Patients on Daclizumab (Zinbryta) had fewer clinical relapses than patients taking Avonex. The second trial compared Daclizumab (Zinbryta) with placebo and included 412 participants who were treated for 52 weeks. In that study, patients receiving Daclizumab (Zinbryta) had fewer relapses compared to those receiving placebo.
Daclizumab (Zinbryta) comes with serious safety risks, however, and should therefore generally be used only in patients who have had an inadequate response to two or more MS drugs previously. The most serious and sometimes fatal safety risks of Daclizumab (Zinbryta) include liver injury and immune conditions. Because of these risks, Daclizumab (Zinbryta) has a boxed warning and is available only through a restricted distribution program under a Risk Evaluation and Mitigation Strategy (REMS). The boxed warning tells prescribers that the drug can cause severe liver injury, including life-threatening and fatal events. Health care professionals should perform blood tests to monitor the patient’s liver function prior to starting Daclizumab (Zinbryta), monthly before each dose, and for up to six months after the last dose. The boxed warning also highlights other important risks of Zinbryta treatment including immune conditions, such as inflammation of the colon (non-infectious colitis), skin reactions, and enlargement of lymph nodes (lymphadenopathy). Additional highlighted warnings include hypersensitivity reactions (anaphylaxis or angioedema), increased risk of infections, and symptoms of depression and/or suicidal ideation.
The most common adverse reactions reported by patients receiving Daclizumab (Zinbryta) in the clinical trial that compared it to Avonex include cold symptoms (nasopharyngitis), upper respiratory tract infection, rash, influenza, dermatitis, throat (oropharyngeal) pain, eczema, and enlargement of lymph nodes. The most common adverse reactions reported by patients receiving Daclizumab (Zinbryta) when compared to placebo are depression, rash, and increased alanine aminotransferase, a fluid biomarker for disturbed liver function.