TL;DR
Get health and wellness essentials delivered free with Prime
- Fast, free delivery on millions of items
- Prime Video, Amazon Music and more included
- Member-only deals all year
A participant in the phase I Breakfree-2 study of the CAR-T therapy zola-cel died of septic pneumonia 44 days after treatment. Investigators said the event followed high-dose cyclophosphamide and remains under investigation; the study’s reported potential benefits are based on early, uncontrolled data.
A participant in the phase I Breakfree-2 study of the investigational CAR-T therapy zolacabtagene autoleucel (zola-cel) died of septic pneumonia 44 days after treatment, according to a presentation by Cleveland Clinic neurologist Jeffrey Cohen. The fatal event, which occurred after the study’s June 2026 data cutoff, is still being investigated and adds a serious safety concern to early research into CAR-T treatment for multiple sclerosis.
Cohen reported the death at MSToronto2026, a joint meeting of the European and Americas committees for treatment and research in multiple sclerosis. The participant had highly active relapsing MS. On day 17 after the zola-cel infusion, the patient developed rigidity and tremor, described as extrapyramidal motor symptoms, and received intermittent corticosteroids and intravenous immunoglobulin.
On day 41, the patient received high-dose cyclophosphamide to target circulating CAR-T cells after clinicians identified no alternative cause for the symptoms. Septic pneumonia developed on day 43, and the patient died the following day. Cohen said the cause and development of the event are not fully understood. He also noted that the patient’s CAR-T cell expansion was in line with that of other participants.
The death was not reported as a case of immune effector cell-associated neurotoxicity syndrome (ICANS). The report said there were no other Grade 5 events in Breakfree-2 or among 190 patients who had received zola-cel in phase I studies for autoimmune diseases. Those details do not establish what caused this death; the event remains under review.
A Serious Safety Finding in MS CAR-T Research
The death matters because Breakfree-2 is testing an approach that may produce a different kind of immune intervention from established MS medicines. CAR-T cells are engineered to target cells carrying CD19, a marker found on B cells. The treatment is intended to deplete those cells and may, researchers propose, reset parts of the immune system. But the treatment process also involves lymphodepleting chemotherapy, and this participant received additional high-dose cyclophosphamide after developing symptoms.
The reported event underscores how much remains to be learned about risks, treatment protocols and patient monitoring in autoimmune-disease CAR-T studies. It does not establish that zola-cel, cyclophosphamide, or another factor alone caused the fatal infection. The timing and clinical details are important, but the mechanism has not been determined.
The study also reported possible signs of benefit, including that patients in the higher-dose group were off disease-modifying therapies at last follow-up. Those results need cautious interpretation: the trial is an early-phase study, was not described as controlled, and has limited follow-up. The safety finding and preliminary efficacy data are both part of an incomplete evidence picture, not proof of how the therapy would perform in wider clinical use.
multiple sclerosis symptom and medication tracking journal
As an affiliate, we earn on qualifying purchases.
As an affiliate, we earn on qualifying purchases.
What Breakfree-2 Has Reported So Far
Breakfree-2 was designed to study zola-cel in three groups: people with highly active relapsing MS, people with progressive MS, and people with refractory myasthenia gravis. Cohen’s presentation focused on the MS groups. They included 66 participants: 30 with highly active relapsing MS and 36 with progressive MS, comprising 12 with primary progressive and 24 with non-relapsing secondary progressive MS.
Participants received lymphodepleting treatment with fludarabine and cyclophosphamide before a single zola-cel infusion. Safety and tolerability were the primary endpoint; efficacy was secondary. The report said cytokine release syndrome occurred in 42.4% of participants, with reported cases at grade 1 or 2 resolving in a median of two days. ICANS occurred in 7.6%, mostly at grade 1 or 2 and resolving in a median of two days. One grade 4 ICANS event in a progressive MS participant resolved within four days after treatment with corticosteroids and anakinra.
At the June 2026 cutoff, the presentation reported that all 60 participants treated at dose level 2 remained off disease-modifying therapies, including nine followed for more than 12 months. Six of seven evaluated patients with highly active relapsing MS met the study’s no-evidence-of-disease-activity criteria at week 26 or later. No new MRI activity was reported in the progressive MS group, and 92% had stable or improved disability progression. These are study findings, not evidence of comparative effectiveness.
“The pathogenesis of that event is not fully understood.”
— Jeffrey Cohen, MD, of the Cleveland Clinic Mellen Center
medical appointment organizer for chronic illness
As an affiliate, we earn on qualifying purchases.
As an affiliate, we earn on qualifying purchases.
Cause and Safety Review Remain Open
The available report does not establish what caused the septic pneumonia or the patient’s death. Cohen said the event’s pathogenesis is not fully understood and that it is still being investigated. The participant received high-dose cyclophosphamide shortly before the pneumonia developed, but the sequence alone does not show that the drug caused the infection or death.
The account does not provide the full case review, any final determination by investigators, or whether the event will lead to changes in dosing, eligibility, monitoring or the study protocol. It also does not specify what additional safety information may be released or when. The reported safety and efficacy rates apply to the study populations and follow-up described, not to all people with MS or all CAR-T products.
digital thermometer for monitoring fever at home
As an affiliate, we earn on qualifying purchases.
As an affiliate, we earn on qualifying purchases.
Investigators Continue the Safety Review
The immediate next step is the ongoing investigation into the fatal event, including clarification of its cause and whether the treatment protocol or care contributed. The source report does not give a timeline for those findings or describe a specific decision about the Breakfree-2 trial following the death.
Separately, Bristol Myers Squibb paused its zola-cel program in September to evaluate safety findings, according to the report. It is not clear from the available information whether that pause was directly prompted by this participant’s death, which occurred after the study data cutoff. Further study updates will be needed to show how the case affects the program and to provide longer-term evidence on both safety and possible benefit.
medical alert bracelet for serious health conditions
As an affiliate, we earn on qualifying purchases.
As an affiliate, we earn on qualifying purchases.
Key Questions
What happened in the zola-cel MS study?
A participant with highly active relapsing MS developed motor symptoms after treatment, later received high-dose cyclophosphamide, developed septic pneumonia on day 43 and died on day 44 after the zola-cel infusion. The event occurred after the study’s June 2026 data cutoff.
Has the cause of death been determined?
No. Presenter Jeffrey Cohen said the event’s pathogenesis is not fully understood and that it remains under investigation. The reported timing does not by itself establish what caused the pneumonia or death.
Was the death attributed to ICANS?
The report said the death was not related to ICANS. It described the fatal event as septic pneumonia and said investigators were still examining its cause.
What did the study report about possible benefits?
The presentation reported that participants in the higher-dose group remained off disease-modifying therapies at last follow-up and described other disease-activity findings. These were early results from a phase I study with relatively short follow-up and no reported controlled comparison, so they do not establish effectiveness.
What happens next for the study?
Investigators are continuing to review the fatal event. The available report does not say when findings will be released or whether the case will lead to changes in the trial protocol or the broader zola-cel program.
Source: rss
Halloween Picks
halloween
As an affiliate, we earn on qualifying purchases.
