Exploring possibilities to improve the risk:benefit balance through anlaysis of the ocrelizumab phase II extension study

Exploring possibilities to improve the risk:benefit balance through anlaysis of the ocrelizumab phase II extension study

Multiple sclerosis is the major demyelinating disease of the central nervous system. Although considered to be a T cell-mediated autoimmune disease it has been shown that CD20 B cell-depleting antibodies exhibit high efficacy in the control of relapsing MS. We have recently suggested that all current MS drugs act because they target memory B cells, a subset of B cells within the CD20 population. Although the B cell subset depletion potential of ocrelizumab has not been reported, we know that other similar agents deplete memory B cells for months to years. However, ocrelizumab treatment is given every six months to ensure that all B cells are depleted at a time when there may not be any CD20 positive memory B cells present in the circulation. Memory B cell depletion can last for years and suggests that treatment effects may therefore last for years also, as found with other multiple sclerosis drugs that similarly deplete memory B cells. Therefore, it may be possible to achieve similar benefit with less frequent drug administration and thus avoiding or reducing potential drug-related side-effects, particularly as it is known that total B cell elimination leaves one susceptible to serious infection.This study examines the long-term effect, at least 18 months, of a short-term treatment cycle and may provide information on the duration of efficacy and information of the durability of the lymphocyte depletion. Although the study was done many years ago it has not been reported fully, yet based on scientific meetings reports found in the public domain, there may be durability of efficacy offering the possibility of a drug-free pregnancy, and provides insight on how ocrelizumab may be working. The objective of the study is to examine whether ocrelizumab has a durability of action longer than 6 months and to obtain data that will help to justify future studies that can may make ocrelizumab even safer.

[{ "PostingID": 14596, "Title": "ROCHE-WA21493", "Description": "Phase II, Multicenter, Randomized, Parallel-Group, Partially Blinded, Placebo and Avonex Controlled Dose Finding Study to Evaluate the Efficacy As Measured by Brain MRI Lesions, and Safety of 2 Dose Regimens of Ocrelizumab in Patients With RRMS" }]