A Randomized, Double-Blind, Placebo-Controlled Phase 3 Trial of Descartes-08 in Patients With Generalized Myasthenia Gravis (MG)

Overview

Sponsor-declared trial summary

Key facts

Sponsor

Cartesian Therapeutics Inc.

Participant type

Patients

Age range

18-64 years, 65+ years

Gender

Male and Female

Therapeutic area

Diseases [C] - Nervous System Diseases [C10]

Trial duration

10 Oct 2025 → ongoing

Decision date (initial)

2025-08-06

Transition trial

No

Low-intervention

No

Rare-disease indication

Yes

Vulnerable population

No

Funding sources

Cartesian Therapeutics, Inc.

External identifiers

EU CT number

2024-520355-25-00

WHO UTN

U1111-1317-9870

ClinicalTrials.gov

NCT06799247

Trial design

CTIS Part I — objectives, methods, condition coding

Main objective

Scope: Therapy, Efficacy, Safety

To evaluate the efficacy of Descartes-08 as assessed by the proportion of Myasthenia Gravis Activities of Daily Living (MG-ADL) responders at Month 4.

Secondary objectives 4

1. To evaluate the efficacy of Descartes-08 as assessed by the proportion of Myasthenia Gravis Composite (MGC) responders at Month 4.
2. To evaluate the efficacy of Descartes-08 as assessed by the proportion of Quantitative Myasthenia Gravis (QMG) responders at Month 4.
3. To evaluate the efficacy of Descartes-08 by comparing the mean decrease from baseline MGC, MG-ADL and QMG at Month 4 after Descartes-08 versus placebo.
4. To evaluate the safety, tolerability and efficacy of Descartes-08 versus placebo in the overall population and in subgroups.

Conditions and MedDRA coding

generalized myasthenia gravis

Regulatory references

Scientific advice from competent authorities

Food And Drug Administration, European Medicines Agency

Plan to share IPD

No

Eligibility criteria

Principal inclusion / exclusion criteria as submitted by sponsor

Inclusion criteria 9

1. Patient must be at least 18 years of age.
2. Patient must have gMG, MGFA clinical classification grades II-IV at Screening.
3. MG-Activities of Daily Living (MG ADL) total score ≥ 6
4. Concomitant immunosuppressive drugs must be deemed necessary by the Investigator. The patient must be on a stable dose for a minimum of 8 weeks prior to Baseline visit.
5. If a patient is using corticosteroids, the daily dose should not exceed 40 mg/day of prednisone (or equivalent). The dose must be stable for a minimum of 8 weeks prior to Baseline visit.
6. Acetylcholine receptor autoantibody (anti-nAChR) titer or anti-AChR cluster antibody must be above the reference laboratory upper normal limit (UNL) and documented within the past 10 years of Screening.
7. Patient must be willing to return for all study visits.
8. Patient must be able to provide written informed consent.
9. Women of childbearing potential must agree to use highly effective birth control from Screening until 14 days post last dose of Descartes-08.

Exclusion criteria 15

1. Major chronic illness that is not well managed at the time of study entry and in the opinion of the Investigator, may increase the safety risk to the patient.
2. Diagnosis of gMG within 12 months of Screening.
3. No history of systemic treatment for gMG other than acetylcholine esterase inhibitors.
4. Diagnosis of a neuromuscular disease other than gMG.
5. Patient is pregnant or lactating.
6. Treatment with IVIG or plasma exchange within 4 weeks prior to the Baseline visit.
7. Ongoing treatment with rituximab/ocreluzimab or calcineurin inhibitors, e.g., tacrolimus, cyclosporine or cyclophosphamide or Neonatal Fc receptor antagonists, e.g. efgartigimod.
8. The patient has started treatment with a complement 5a (C5a) inhibitor, such as eculizumab, within 8 weeks prior to the Baseline visit.
9. Prior treatment with BCMA-directed therapy (e.g. monoclonal antibody, T-cell engager, or CAR-T).
10. Abnormal PT/INR or PTT increased > 1.5-fold above the normal range at Screening or the patient is on anticoagulation therapy (except in cases of elevated PTT with documented lupus anticoagulant; or in patients who have been on stable doses of anticoagulation therapy for more than 6 months of VTE diagnosis; or in patients on stable doses of anticoagulation therapy for at least 8 weeks of atrial fibrillation diagnosis; these conditions will not be exclusionary unless, in the investigator’s opinion, they make participation in the study unsafe).
11. ANC < 1000 cells/microliter
12. Hemoglobin < 8.0 g/dL
13. Platelets: < 50,000/mm at screening
14. Creatinine Clearance < 30 mL/min at Screening
15. History of primary immunodeficiency, organ, or allogeneic bone marrow transplant

Endpoints

Primary and secondary outcome measures (English text)

Primary endpoints 1

1. Proportion of participants who have a decrease of ≥3 points in MG-ADL score at Month 4 compared to Baseline in the active versus placebo group.

Secondary endpoints 7

1. Proportion of participants who have a decrease of ≥4 points in MGC score at Month 4 compared to Baseline in the active versus placebo group.
2. Decrease from Baseline at Month 4 in MG-ADL score in active versus placebo groups.
3. Decrease from Baseline at Month 4 in MGC score in active versus placebo groups.
4. Proportion of participants who have a decrease of ≥4 points in QMG score at Month 4 compared to Baseline in the active versus placebo group.
5. Decrease from baseline in MG-ADL score at Month 2 and Month 3 follow-up in the active versus placebo group.
6. Decrease from baseline in MGC score at Month 2 and Month 3 follow-up in the active versus placebo group.
7. Decrease from Baseline at Month 2, Month 3 and Month 4 in QMG score in active versus placebo groups.

Investigational products

Investigational medicinal products (IMPs), comparators, placebo, auxiliary

Test 1

Placebo 1

Sponsors and contacts

Sponsor organisations, regulatory contacts, third parties

Cartesian Therapeutics Inc.

Sponsor organisation

Cartesian Therapeutics Inc.

Address

7495 New Horizon Way

City

Frederick

Postcode

21703-8388

Country

United States

Scientific contact point

Organisation

Cartesian Therapeutics Inc.

Contact name

Cartesian Regulatory Affairs

Public contact point

Organisation

Cartesian Therapeutics Inc.

Contact name

Cartesian Clinical Trials

Third parties 8

Locations

3 EU/EEA countries · 9 investigational sites

By country

Investigational sites

Country notifications

Trial-start, recruitment-start, end and early-termination notifications submitted per Member State

Results and documents

Annex IV summary of results, Annex V layperson summary, and all documents registered in CTIS for this trial

Documents 43 files

Public protocol annexes, IB summaries, regulatory submissions and post-authorisation documents registered in CTIS.

Application history

5 submissions — initial application plus substantial / non-substantial modifications