Zinbryta (daclizumab) for the Treatment of Multiple Sclerosis, United States of America
Zinbryta (daclizumab) is an injectable formulation jointly developed by Biogen and Abbive for the treatment of relapsing forms of multiple sclerosis in adults.
The biological license application (BLA) for Zinbryta (daclizumab) was submitted to the US Food and Drug Administration (FDA) on 27 February 2015. The FDA approved Zinbryta (daclizumab) as a once-a-month, self-administered, subcutaneous treatment for multiple sclerosis in adults, on 27 May 2016.
The Committee for Medical Products for Human Use (CHMP) of the European Medical Agency recommended a positive opinion to grant marketing authorisation for Zinbryta (daclizumab) on 28 April 2016 and the same is now under review by the European Commission.
The application to approve Zinbryta is also under regulatory review in Switzerland, Canada and Australia.
Causes of multiple sclerosis
Multiple sclerosis is a chronic, often disabling neurological disorder caused due to the damage of the myelin sheath that surrounds and protects the nerves cells. It usually attacks the central nervous system, which includes brain, spinal cord and optic nerves.
The damage of the myelin sheath causes slowing down or blockage of messages between brain and body, resulting in a number of symptoms associated with the disease, such as visual disturbance, muscle weakness, trouble with co-ordination, numbness, and pricking and memory problems.
Multiple sclerosis is usually termed as an autoimmune disease, where the body's immune system attacks the health cells accidentally. It is more commonly seen in women between in age group from 20 to 40.
There is no permanent cure for the disease, but medicines may control the symptoms and slow it down considerably.
Zinbryta (daclizumab)'s mechanism of action
The exact mechanism of action of Zinbryta is unknown. It is a new form of a humanised monoclonal antibody, which binds to CD25, a high-affinity interleukin-2 (IL-2) receptor subunit on T-cells that become activated in people suffering from multiple sclerosis.
Zinbryta modulates the interleukin-2 (IL-2) signalling without causing any immune cell depletion. It should be referred to patients with relapsing multiple sclerosis (RMS), who have had an inadequate response to two or more therapies.
The US FDA approved Zinbryta (daclizumab) based on the results obtained from two clinical trials, namely DECIDE and SELECT, which were conducted on more than 2,400 patients with relapsing forms of multiple sclerosis (RMS).
SELECT is a multi-centre, randomised, double-blinded, phase 2b study conducted in more than 417 patients with RMS to evaluate the safety and efficacy of Zinbryta 150mg and 300mg against placebo. The drug was administered to the patients subcutaneously for every four weeks for one year.
DECIDE is a phase 3, global, randomised, double-blinded, multi-centre study conducted in 1,841 patients suffering from RMS.
The study included two arms, one of them were given 150mg of subcutaneous Zinbryta every four weeks and compared with the second arm of patients, who were given AVONEX (interferon beta-1a) 30mcg IM once a week.
The trial has achieved the primary endpoint of significant reduction in annualised relapse rate (ARR) and first secondary end point of reduction in the number of newly enlarging T2 hyper-intense lesions.
The study, however, did not demonstrate a statistical significance in secondary end point of evaluating proportion of patients with sustained disability progression, measured by Expanded Disability Status Scale (EDSS) after 12 weeks.
The commonly observed adverse reactions in patients treated with Zinbryta were nasopharyngitis, upper respiratory tract infection, rash, influenza, dermatitis, oropharyngeal pain, bronchitis, eczema, lymphadenopathy, depression and increased alanine aminotransferase (ALT).