Bristol Myers Squibb Presents Interim Safety, Efficacy Data From Its Multiple Sclerosis Groups Of Phase 1 Trial Of Zolacabtagene Autoleucel At MSToronto 2026

Bristol Myers Squibb (NYSE:BMY) today announced disclosure of interim safety and efficacy results from the multiple sclerosis (MS) cohorts of the Phase 1, single-arm, dose-escalation Breakfree-2 study evaluating zolacabtagene autoleucel (zola-cel; BMS-986353), an investigational, autologous CD19-directed CAR T cell therapy, in patients with highly active relapsing MS (haRMS) and progressive forms of MS (PMS). The data are being presented today in an oral presentation (Abstract #1615) at MSToronto 2026, the 10th Joint ACTRIMS-ECTRIMS Meeting taking place in Toronto, Canada.

The study included 66 patients (30 patients with haRMS and 36 patients with PMS) with ongoing disease activity or worsening disability despite treatment. Patients had a median of two prior disease-modifying therapies (DMTs) (range: 1-8 haRMS; 1-6 PMS). The primary endpoint of the study was safety, with efficacy as the secondary endpoint. The data presented show a safety profile consistent with previously reported zola-cel Phase 1 clinical trial data and early, promising efficacy across both haRMS and PMS with all patients treated at dose level 2 (DL2) (60/60) remaining off DMTs.

In the Breakfree-2 study, the majority of adverse events were brief and reversible, generally consistent with previously reported zola-cel Phase 1 clinical trial data.

• Overall, 42.4% of patients (28/66) had cytokine release syndrome (CRS) events. Majority were Grade 1 (36.4%), with some Grade 2 (6.1%) and all resolved in a median of two days.
• 7.6% of patients (5/66) had immune effector cell-associated neurotoxicity syndrome (ICANS), most of which were Grade 1/2, which resolved in a median of two days.
• One Grade 4 ICANS event occurred in a patient with PMS and was managed with corticosteroids and anakinra and resolved within four days.