Cabaletta Bio Announces Initial Clinical Data From Phase 1/2 RESET-Myositis And RESET-SLE Trials Of CABA-201

– No CRS, ICANS, infections or serious adverse events observed in either of the first two patients through data cut-off of May 28, 2024 –

– CABA-201 exhibited anticipated profile of CAR T cell expansion and contraction with complete B cell depletion observed in both patients by day 15 post-infusion –

– Improvements in both patients' specific disease measures, consistent with academic experience of a similar 4-1BB CD19-CAR T, suggest emerging clinical benefit with CABA-201 while discontinuing all disease-specific therapies other than a planned steroid taper in one patient –

– Immature, naïve B cell repopulation in first IMNM patient observed at week 8 consistent with a potential immune system reset –

– 18 sites open and recruiting across four Phase 1/2 RESET™ trials with 5 patients enrolled as of June 12, 2024; initial clinical and translational data support continued development of CABA-201 at the current dose –