Cabaletta's rese-cel gMG data due in H2 2026, months after AAN preview
The RESET-MG trial's complete Phase 1/2 dataset is coming after a partial April 2026 presentation showed clinical responses in most evaluable patients, setting up whether the full cohort holds up.
Executive Summary
- Cabaletta Bio will present a complete version of a dataset it has already partially disclosed, extending a small trial's early clinical signal rather than opening a new readout.
- An interim look earlier in 2026 showed clinically meaningful improvement in most evaluable patients along with the expected pattern of CAR T expansion and B-cell depletion, with a favorable safety read.
- The study is registered to test safety first; efficacy measures sit as secondary endpoints in a 12-patient, non-registrational cohort, which limits how much any single update can establish.
- Rese-cel has no approved or late-stage precedent using this mechanism in this indication, with the nearest peer, a CD19-targeted CAR T from Novartis, still earlier in testing.
The catalyst
Cabaletta Bio said in a November 2025 business update that it planned to present complete Phase 1/2 data from RESET-MG in the second half of 2026. The trial, registered as NCT06359041, is a Phase 1/2 study of rese-cel, formerly CABA-201, an autologous CD19-directed CAR T cell therapy administered as a single intravenous infusion in adults with generalized myasthenia gravis. The study targets 12 patients, is active but no longer recruiting, and its registered primary endpoint is the incidence and severity of adverse events, with MG-ADL, Myasthenia Gravis Composite, and Quantitative Myasthenia Gravis score changes listed as secondary measures. Cabaletta+1Cabaletta Bio Reports Third Quarter 2025 Financial Results and Provides Business UpdateNov 10, 2025RESET-MG: A Study to Evaluate the Safety and Efficacy of CABA-201 in Participants With Generalized Myasthenia GravisNCT06359041
Probability of SuccessBased on the AppliedXL Probability of Success model. For more information about the methodology, read the research here.
What the interim data already showed
Before the H2 2026 window opens, Cabaletta already presented a version of this dataset. At the AAN Annual Meeting on April 20, 2026, the company reported that among evaluable patients, 5 of 7 who were AChR-antibody-positive and 5 of 6 who were AChR-antibody-negative had clinically meaningful improvement on the MG-ADL scale, alongside CAR T cell expansion and B-cell depletion and a safety profile described as generally favorable. That presentation covered the same 12-patient enrollment target as the registered trial. The H2 2026 event will show whether that response pattern holds as more patients accrue follow-up and whether the complete dataset changes the picture materially from the April interim look. Cabaletta+1Cabaletta Bio Reports Third Quarter 2025 Financial Results and Provides Business UpdateNov 10, 2025RESET-MG: A Study to Evaluate the Safety and Efficacy of CABA-201 in Participants With Generalized Myasthenia GravisNCT06359041
Trial design and its limits
The trial's registered primary endpoint is safety, not efficacy: it measures adverse event incidence and severity in a single-arm, open-label design with no comparator arm. A 12-patient, non-registrational trial with a safety-first primary endpoint is built to establish tolerability, not a decision-grade efficacy claim. The enrollment target has not changed since the trial's design, holding at 12 patients, which the trial's own operational-risk profile treats as a routine, unremarked figure. The primary completion date has moved once, from July 2028 to September 2029, a change recorded in April 2024, well before the current catalyst window. NCT06359041RESET-MG: A Study to Evaluate the Safety and Efficacy of CABA-201 in Participants With Generalized Myasthenia GravisNCT06359041
Competitive and mechanistic context
No CD19-targeted CAR T therapy has reached approval or late-stage testing in generalized myasthenia gravis. The nearest direct comparator is Novartis's rapcabtagene autoleucel, another CD19-directed CAR T in Phase 1/2 testing for the same indication (NCT06704269); Amgen's inebilizumab, a CD19-targeting monoclonal antibody, is also in Phase 2 testing in the same disease (NCT06987539). Neither has disclosed comparable clinical results. Established gMG therapies such as argenx's efgartigimod target FcRn rather than CD19, a different mechanistic hypothesis, and are not direct comparators. With no validated CD19-depletion precedent in this indication, a complete dataset that reproduces the interim response pattern across the full enrolled cohort, rather than in a subset of evaluable patients, would be the result that distinguishes this update from the April preview.
This analysis was produced using AI-assisted reporting systems, AppliedXL data, and official public records. These systems undergo editorial review, quality checks, and regular audits by human experts. Errors may still occur, as with any automated system. Always consult the linked primary sources. Read our AI Editorial Policy.