Descartes-08 in Autoantibody Myositis

April 22, 2026 updated by: Cartesian Therapeutics

A Randomized Double-Blind Placebo-Controlled Study to Evaluate Efficacy, Safety, and Tolerability of Descartes-08 in Patients With Dermatomyositis and Antisynthetase Syndrome

This is a randomized, double-blind, placebo-controlled phase 2 study to evaluate the efficacy, safety and tolerability of an autologous T-cells expressing a chimeric antigen receptor (CAR) directed to B-Cell maturation antigen (BCMA) in patients with autoantibody-mediated myositis, including antisynthetase syndrome (ASyS) and dermatomyositis (DM).

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

60

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • United States
    • North Carolina
      • Chapel Hill, North Carolina, United States, 27599
        • Recruiting
        • T13
    • Texas
      • Austin, Texas, United States, 78759
        • Recruiting
        • T23

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Confirmed diagnosis of one of the following:

Dermatomyositis (DM): Probability score ≥55% on the 2017 EULAR/ACR (European Alliance of Associations of Rheumatology/ American College of Rheumatology) criteria for classification of dermatomyositis (corresponding to diagnosis of 'probable or definite' DM). OR Antisynthetase Syndrome (ASyS): Diagnosis based on ACR/EULAR Classification Criteria (1)."

  • Participants must have dermatomyositis or antisynthetase syndrome with muscle and/or skin involvement.
  • Refractory or intolerance to standard therapy.
  • Stable background immunosuppressive therapy for ≥8 weeks.
  • Adequate hematologic, renal, hepatic, and pulmonary function (SpO₂ ≥92% on room air).
  • Informed consent, compliance with visits, contraception, and vaccinations required.

Exclusion Criteria:

  • Isolated interstitial lung disease (ILD) without muscle or skin involvement

    • Severe irreversible muscle damage or advanced weakness (e.g., wheelchair-bound).
    • Interstitial lung disease (ILD) requiring oxygen, severe pulmonary impairment (FVC ≤45%, DLCO ≤40%), or pulmonary hypertension.
    • Other inflammatory myopathies (PM, IMNM, IBM, cancer- or drug-induced myositis, overlap myositis except Sjögren's).
    • Other severe neuromuscular, cardiac, pulmonary, or systemic autoimmune diseases requiring immunosuppression.
    • Significant uncontrolled chronic illnesses or psychiatric conditions interfering with participation.
    • Pregnancy or lactation.
    • Recent use of prohibited immunosuppressants/biologics or investigational agents (per washout periods).
    • Live vaccination within 4 weeks.
    • History of primary immunodeficiency, organ or bone marrow transplant.
    • Active or uncontrolled infections: HBV, HCV, HIV, tuberculosis, or recurrent/severe infections.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Placebo Comparator: Placebo
Other: Placebo
Plasma-Lyte
Experimental: Decartes-08
Drug: Descartes-08
Autologous T-cells expressing a chimeric antigen receptor (CAR) directed to B-Cell maturation antigen (BCMA)

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Major improvement of 2016 ACR/EULAR Total Improvement score
Time Frame: 24 weeks
Proportion of participants in the Descartes-08 group compared with placebo who achieve major improvement marked by ≥60 point improvement on the 2016 ACR/EULAR Total Improvement Score (TIS)
24 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Cartesian Therapeutics

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

  • Fedak, R.R., Ruggerie, R.N., Shan, Y. et al. BCMA-directed mRNA CAR-T cell therapy for myasthenia gravis: exploratory biomarker analysis of a placebo-controlled phase 2b trial. Nat Med (2026). https://doi.org/10.1038/s41591-025-04170-z

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

April 28, 2026

Primary Completion (Estimated)

November 1, 2027

Study Completion (Estimated)

May 1, 2028

Study Registration Dates

First Submitted

January 29, 2026

First Submitted That Met QC Criteria

January 29, 2026

First Posted (Actual)

February 6, 2026

Study Record Updates

Last Update Posted (Actual)

April 23, 2026

Last Update Submitted That Met QC Criteria

April 22, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • RNAC-TRITON-08

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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