B-cells

NurOwn May Curb Damaging Neuroinflammation in MS, Study Finds

NurOwn, believed to haveĀ neuroprotective and repairing effects,Ā may also be able to curb the damaging immune responses that contribute to multiple sclerosis (MS) progression, a recent study found. This newly identified potential may extend the benefits of this cell-based therapy, its researchers believe. The findings were to be presented…

#ACTRIMS2020 – Ofatumumab Self-injection Pen May Be ‘Very Attractive’ Option for Relapsing MS

Monthly under-the-skin injections of Novartisā€™Ā investigational candidate ofatumumab show promise as a convenient, effective, and safe therapeutic option for people with relapsing multiple sclerosisĀ (MS). Data from the ASCLEPIOS and APLIOS clinical trials showed that ofatumumab ā€” currently under regulatory review for possible approval in the U.S. and Europe…

Mayzent Helps Regulate the Immune System in SPMS, Study Shows

Mayzent (siponimod), an approved oral therapy for activeĀ secondary progressive multiple sclerosisĀ (SPMS), promotes a more regulatory immune system, which may explain its added benefits for SPMS, new clinical data show. The study ā€œSiponimod enriches regulatory T and B lymphocytes in secondary progressive multiple sclerosisā€ was published in the…

Tysabri May Promote Inflammatory B-Cell Activation in MS Patients, Study Says

Tysabri (natalizumab), an effective T-cell targeting treatment for multiple sclerosisĀ (MS),Ā seems to also promote the activation of pro-inflammatory immune B-cells in people with this disease, a studyĀ found. The study, “Natalizumab promotes activation and pro-inflammatory differentiation of peripheral B cells in multiple sclerosis patients,” was published in the…

#ACTRIMS2019 – TG Therapeutics’ Investigational Therapy Ublituximab Posts Positive Data in MS Phase 2 Clinical Trial

Full results of a Phase 2 clinical trial testing TG Therapeuticsā€™ lead candidate ublituximab (TG-1101) for relapsingĀ multiple sclerosisĀ (MS) showed that treatment for 48 weeks resulted in a marked reduction of brain and spinal cord lesions, an almost complete depletion of relapse-associated immune B-cells, and significantly halted disability…

Ocrevus Targets Certain T-Cells, Along with B-Cells, in MS Patients, Study Reports

Treatment with a single dose of Ocrevus (ocrelizumab) depleted a subset of immune T-cells within two weeks in patients with relapsing multiple sclerosis (MS) or primary progressive MS (PPMS), according to a study. The study, ā€œOcrelizumab Depletes CD20+Ā T Cells in Multiple Sclerosis Patients,ā€ was published in the journal Cells. AutoreactiveĀ immune T-cells, which attack the bodyā€™s own tissues, have been regarded as the primary mediator of MS; however, this view has been challenged by the effectiveness of therapies targeting immune B-cells that contain the CD20 cell surface protein in reducing disease activity. One such therapy isĀ Genentechā€™s Ocrevus, an anti-CD20 monoclonal antibody, which was first approved in the U.S. in 2017 for patients with relapsing MS or PPMS. Because CD20 is mainly expressed by B-cell precursors and mature B-cells, Ocrevus is often considered to selectively deplete CD20-containing B-cells. However, CD20 is also expressed by highly activated T-cells with the CD3 protein marker, characterized by the increased production of proinflammatory molecules, or cytokines. These T-cells are found in the blood, cerebrospinal fluid ā€” the liquid surrounding the brain and spinal cord ā€” and chronic brain lesions of MS patients, and show an elevated expression of the CD8 and CD45 markers. Off-label use of rituximabĀ (marketed as Rituxan in the U.S. and MabThera in Europe), a lymphoma and rheumatoid arthritis treatmentĀ that also targets CD20, has been associated with the depletion of CD20-containing T-cells in MS patients. Therefore, targeting this T-cell subtype has been hypothesized as an additional mechanism for rituximabā€™s clinical effectiveness. However, scientists did not know whether Ocrevus, which is different from rituximab in terms of CD20 binding and cell toxicity, also depletes CD20-positive T-cells. To address this unknown, a team from Hannover Medical SchoolĀ in Germany analyzed blood samples of MS patients through a technique called multicolor flow cytometry prior to the first dose of Ocrevus and after two weeks, immediately before the second dose. They intended to evaluate the characteristics of the patientsā€™ peripheral blood mononuclear cells, which include T-cells, B-cells, monocytes, and macrophages. A total of 21 patients (13 women) were included, with a median age of 43 years (range 22-65 years). Of the participants, 17 had the relapsing form of the disease forĀ a median of 14.6 years, while four had PPMS for a median of 5.6 years. The analysis found T-cells containing CD20 and CD3 in all patients. These cells accounted for 2.4% of all CD45-expressing lymphocytes ā€” white blood cells that include T- and B-cells ā€” and for a significant proportion (18.4%) of all CD20 cells. Evaluation of the cellsā€™ fluorescence intensity revealed that CD20 levels were significantly lower on T-cells than on B-cells also expressing this marker. Treatment with one dose of Ocrevus substantially lowered the levels of CD20-positive T- and B-cells within two weeks, reflected by a frequency of 0.04% and an absolute cell count decrease from 224.9 to 0.57/microliter. ā€œOur results demonstrate that treatment with [Ocrevus] does not exclusively target B-cells, but also CD20+ T-cells, which account for a substantial amount of CD20-expressing cells,ā€ the researchers wrote. ā€œThese findings suggest that CD20+ T-cells might play a pivotal role in the pathogenesis of MS, and we speculate that depletion of CD3+CD20+ cells by anti-CD20 monoclonal antibodies might contribute to the efficacy of anti-CD20 therapy,ā€ they added. However, they also emphasized that the findings need to be confirmed in studies with larger groups of MS patients.

Lemtrada Can Lower Number of B-cells Infiltrating Nervous System and Forming Clumps, Animal Study Shows

Treating mice in a model of multiple sclerosis with Lemtrada (alemtuzumab)Ā prevented the formation of B-cell aggregates in the animals’ central nervous system and disrupted already existing ones, researchers report. The treatment alsoĀ reduced disease activity when administered at the peak of disease. The study, ā€œAnti-CD52 antibody treatment depletes B…