Patients with progressive forms of multiple sclerosis (MS) have limited
therapeutic options and require new, effective treatments. Ocrelizumab, an
anti-CD20 monoclonal antibody (mAb) that depletes B cells, is currently
the only approved drug in the United States for primary progressive MS
(PPMS). Although ocrelizumab has been shown to deplete B cells in the
cerebrospinal fluid (CSF), a lack of reduction of oligoclonal bands (OCBs)
or immunoglobulin G (IgG) index indicates incomplete depletion and
continued persistence of pathogenic B cells in the brain (Yu 2013), which
could limit its potential efficacy. In addition to anti-CD20 antibodies, only
siponimod, a small molecule drug targeting sphingosine 1 phosphate (S1P)
receptor, and cladribine, a purine nucleoside analogue, are currently
approved for secondary progressive MS (SPMS). None of these medications
fully halt or reverse disease progression. Chimeric antigen receptor
(CAR)-T cells targeting CD19 have a wider spectrum of B-cell depletion
than anti-CD20 mAbs and can target central nervous system (CNS)-resident
B cells by crossing the blood-brain-barrier (BBB) (Richter 2024, Dunn 2025,
Seshadri 2024). These autologous CD19 CAR-T cell therapies have recently
shown early signs of efficacy in MS (Dunn 2025) and other autoimmune
conditions, although further studies are needed to confirm their
effectiveness and safety (Haghikia 2024).
TRX319 is a novel allogeneic, off-the-shelf CD19 CAR-Type 1 regulatory
T (Tr1) cell product capable of suppressing pathogenic T-cell and
inflammatory responses (by inhibiting the production of pro-inflammatory
cytokines IL-1, IL-6, and TNF-) in addition to robust CD19 CAR
mediated B-cell depletion. Because TRX319 has anti-inflammatory
properties, TRX319 cells are expected to have an improved safety profile
(due to IL-6 inhibition) compared to current effector CD19 CAR-T cell
therapies that can result in cytokine release syndrome (CRS) and immune
effector cell-associated neurotoxicity syndrome (ICANS). Therefore,
TRX319 may represent a novel treatment option for patients with
progressive forms of MS.
Study statuses change often. Please contact us for help.