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miv-cel (KYV-101): experimental CAR-T cells tested in two people with progressive MS

Published by MyelinWatch:

Organisation
University of California, San Francisco research team
Study sponsor
Bruce Cree / University of California, San Francisco

Miv-cel (KYV-101) · miv-cel is made from a person’s own T cells, engineered to target CD19-positive B cells. An early Phase 1 study is testing whether this immune-cell approach can be given to people with treatment-refractory progressive multiple sclerosis (MS). Participants received chemotherapy conditioning before the CAR-T infusion.

What is the approach?

Miv-cel is made by collecting a person’s own T cells and engineering them to recognise CD19 on B cells. After preparatory chemotherapy, the cells are infused to deplete those B cells and potentially reset part of the immune response; whether this changes progressive MS outcomes remains unknown.

Approach source: Gupta et al. — September 2026 medRxiv preprint ↗

What is being studied

miv-cel is made from a person’s own T cells, engineered to target CD19-positive B cells. An early Phase 1 study is testing whether this immune-cell approach can be given to people with treatment-refractory progressive multiple sclerosis (MS). Participants received chemotherapy conditioning before the CAR-T infusion.

Research stage

First study in people — mainly checks safety

The study continues without taking new participants.

What we know so far

A September 2026 preprint describes two treated women with secondary progressive MS. CAR-T cells appeared in cerebrospinal fluid and exploratory immune markers changed. MRI findings were stable and disability scores changed, but these uncontrolled observations do not show that miv-cel improved MS. Reported high-grade adverse effects and laboratory abnormalities included grade 3 liver-enzyme elevation, neutropenia and lymphopenia in participant 1 and grade 4 lymphopenia in participant 2. Participant 1 also had low immunoglobulin requiring replacement and a delayed rash; participant 2 had grade 1 cytokine-release syndrome treated with tocilizumab and dexamethasone. Conditioning chemotherapy may have contributed to blood-count changes. The preprint has not been peer reviewed.

What this means for patients today

This remains an experimental Phase 1 intervention, not an available or proven MS treatment. ClinicalTrials.gov lists NCT06451159 as active but not accepting new participants, while the paper says further recruitment stopped after Kyverna, a study collaborator, shifted its development focus. There is no established Greek study site or access, and no evidence of myelin repair.

Treatment or approach
miv-cel (KYV-101) — experimental anti-CD19 CAR-T cells for progressive MS
How it is intended to work
Autologous anti-CD19 chimeric antigen receptor T cells
Where the study is running
US study; no Greek site or treatment access established
Source: Gupta et al. — medRxiv — original non-peer-reviewed medical preprint ↗Source: ClinicalTrials.gov — NCT06451159, Phase 1 study status and design ↗ Source: PubMed — preprint record PMID 42818477 ↗
Published by MyelinWatch
Last substantive MyelinWatch update

Programme updates — newest research developments first

  1. Phase 1, uncontrolled report of two treated participants; preprintResearch event/source date:

    miv-cel CAR-T: immune findings in two people with progressive MS

    A preprint posted on 11 September 2026 reports two women with treatment-refractory secondary progressive multiple sclerosis (MS) who received low-dose autologous anti-CD19 CAR-T cells, mivocabtagene autoleucel (miv-cel, also called KYV-101), after fludarabine and cyclophosphamide conditioning. CAR-T cells appeared in cerebrospinal fluid and exploratory immune measures changed. MRI findings were stable; observed disability scores changed, but with only two participants, no comparison group and conditioning treatment, these observations cannot establish that miv-cel caused benefit to patients. Reported adverse effects and laboratory abnormalities included grade 3 liver-enzyme elevation, neutropenia and lymphopenia in participant 1, with hypogammaglobulinaemia requiring immunoglobulin and a delayed rash; participant 2 had grade 4 lymphopenia and grade 1 cytokine-release syndrome treated with tocilizumab and dexamethasone. Conditioning chemotherapy may have contributed to blood-count changes.

    Source: Gupta et al. — medRxiv — original non-peer-reviewed medical preprint ↗Source: ClinicalTrials.gov — NCT06451159, Phase 1 study status and design ↗ Source: PubMed — preprint record PMID 42818477 ↗