Last updated: September 2, 2026
Novartis paused eight autoimmune trials of its CD19 CAR T therapy after three patient deaths, Bristol Myers Squibb paused its rival program, and the same day Roche paid Simcere Zaiming $75 million upfront for a preclinical trispecific antibody aimed at the same B cell biology.
This page covers the September 1 autoimmune cell therapy safety pauses at Novartis and Bristol Myers Squibb, the Roche and Simcere Zaiming license, ArsenalBio’s pivot, Novartis’s REMODEL multiple sclerosis results, Alumis’s lupus readout, GSK’s mRNA flu vaccine, the Boston Scientific cyberattack, and Tuesday’s market closes.
Why did Novartis halt its autoimmune CAR T trials?
Novartis temporarily halted its autoimmune program for rapcabtagene autoleucel (rap-cel, also known as YTB323) after three patient deaths from immune effector cell associated hemophagocytic syndrome, or IEC-HS, according to company statements reported by Fierce Biotech and BioSpace. There is no standalone Novartis press release; the figures here come from those statements as carried by trade press.
Rapcabtagene autoleucel is an autologous CD19 directed CAR T cell therapy manufactured on Novartis’s T-Charge rapid manufacturing platform. IEC-HS is a severe systemic hyperinflammatory reaction that can follow rapid expansion of engineered T cells. Novartis said the temporary halt “will allow for a more comprehensive review of the evolving clinical and safety data across the program,” and that it is analyzing the data to identify all contributing factors while engaging independent committees on enhanced monitoring and management. The company’s oncology studies of the same therapy, in chronic lymphocytic leukemia, diffuse large B cell lymphoma, and acute lymphoblastic leukemia, continue unaffected.
Which rapcabtagene autoleucel trials are paused?
Eight autoimmune studies are paused across two phases, per Fierce Biotech’s reporting. The Phase 2 studies cover four diseases and the Phase 1/2 studies cover four more.
| Phase | Indication |
|---|---|
| Phase 2 | Systemic lupus erythematosus / lupus nephritis |
| Phase 2 | Systemic sclerosis |
| Phase 2 | ANCA associated vasculitis |
| Phase 2 | Idiopathic inflammatory myopathies |
| Phase 1/2 | Rheumatoid arthritis |
| Phase 1/2 | Sjogren’s disease |
| Phase 1/2 | Generalized myasthenia gravis |
| Phase 1/2 | Multiple sclerosis (relapsing and non active progressive) |
Why did Bristol Myers Squibb pause its zola-cel trials?
Bristol Myers Squibb voluntarily paused enrollment in autoimmune trials of zolacabtagene autoleucel (zola-cel, BMS-986353) after what the company called transient and reversible inflammatory events. BMS reported no deaths. Zola-cel is also an autologous CD19 directed CAR T built on a rapid manufacturing process, in this case the NEXT T platform.
BMS said it acted “out of an abundance of caution” and wants to complete its evaluation and resume enrollment as quickly as possible. William Blair analysts, cited in the trade coverage, noted at least one prior IEC-HS case associated with zola-cel and suggested a common thread worth investigating: rapid manufacturing platforms may produce cells that expand more aggressively in patients, which could drive both the potency these programs promised and the toxicity now under review. That is a hypothesis, not a finding, and both companies also point to patient level factors as candidates.
What did Roche pay for Simcere Zaiming’s SIM0660?
Roche paid $75 million upfront for exclusive global rights to SIM0660, a preclinical trispecific antibody, with the deal worth up to $1.53 billion including milestones plus tiered royalties reaching double digits, per Simcere Zaiming’s September 1 press release. The upfront is about 4.9 percent of the headline value.
SIM0660 targets CD79a, CD19, and CD3. The CD3 arm engages the patient’s own T cells while the two B cell antigen arms direct the killing, a design intended to deplete B cells, including in patients already treated with CD20 or CD19 directed therapies, while limiting cytokine release. Simcere Zaiming positions it for B cell mediated diseases including autoimmune conditions. Roche receives worldwide development, manufacturing, and commercialization rights; Simcere says it has now signed six licensing deals worth more than $6.1 billion in aggregate, a company figure.
| Term | Value |
|---|---|
| Upfront | $75 million |
| Total potential value | Up to $1.53 billion |
| Royalties | Tiered, up to double digits |
| Stage | Preclinical |
| Rights | Global, exclusive, to Roche |
| Cash share of headline value | ~4.9% |
On the cash share curve this newsletter tracks, 4.9 percent lands exactly in the preclinical and platform band of roughly 4 to 5 percent, alongside Genentech and DualityBio’s ADC license at about 4 percent. The curve’s logic held again: the earlier the asset, the smaller the fraction of the headline number that is real money today.
How do CAR T and T cell engagers compare for autoimmune B cell depletion?
Both approaches aim to reset the immune system by deleting pathogenic B cells, but they differ in manufacturing, dosing, and now, visibly, in risk surface. Tuesday’s news moved capital from one column to the other.
| Feature | Ex vivo CAR T (rap-cel, zola-cel) | Trispecific T cell engager (SIM0660) | In vivo CAR T (ArsenalBio’s new focus) |
|---|---|---|---|
| What it is | Patient’s T cells engineered outside the body, reinfused | Off the shelf antibody recruiting T cells to B cell targets | Gene delivery engineers T cells inside the patient |
| Manufacturing | Per patient, days to weeks even on rapid platforms | Standard biologics manufacturing | No cell manufacturing step |
| Dosing control | One infusion; expansion in the patient is hard to throttle | Dose and schedule adjustable, can be stopped | Depends on delivery vehicle |
| Status in autoimmune disease | Novartis and BMS programs paused | Preclinical (SIM0660); other engagers in clinic across the industry | Preclinical at ArsenalBio |
What happened at ArsenalBio?
Arsenal Biosciences is laying off the majority of its staff, 99 employees according to BioSpace, and refocusing on in vivo CAR T, where the engineering happens inside the patient and the per patient manufacturing step disappears. Fierce Biotech notes this follows a 50 percent workforce reduction last year. The decision predates Tuesday’s safety headlines, but it points the same direction: the industry is losing patience with the cost and complexity of ex vivo cell therapy outside oncology.
What did the REMODEL trials show for remibrutinib in multiple sclerosis?
Both REMODEL-1 and REMODEL-2 met their primary endpoints, with remibrutinib significantly reducing annualized relapse rate versus teriflunomide in relapsing multiple sclerosis, per Novartis’s September 1 release. The release publishes no effect sizes; detailed data go to a late breaker at MSToronto2026.
| Item | Detail (Novartis release) |
|---|---|
| Design | Two identical Phase 3 trials, randomized 1:1, double blind, active comparator |
| Enrollment | About 2,000 patients globally, EDSS 0.0 to 5.5 |
| Arms | Remibrutinib 100 mg vs teriflunomide |
| Primary endpoint | Annualized relapse rate: met in both trials, figures not disclosed |
| Key secondaries | Fewer new or enlarging T2 lesions and gadolinium enhancing T1 lesions; positive trend on 3 month confirmed disability progression; nominally significant 6 month confirmed disability progression in a preplanned combined analysis |
| Liver safety | No liver signal, zero Hy’s law cases; profile consistent with the chronic spontaneous urticaria program of more than 4,500 participants |
| Next step | Global regulatory submissions planned; data at MSToronto2026 |
The liver line matters because hepatotoxicity has been the recurring worry for the oral BTK inhibitor class in multiple sclerosis. Remibrutinib is already approved in the United States as Rhapsido for chronic spontaneous urticaria, so the MS filing would extend an approved molecule rather than introduce a new one.
Why did Alumis stock fall more than 50 percent?
Alumis’s TYK2 inhibitor envudeucitinib missed the primary endpoint of its Phase 2b LUMUS trial in systemic lupus erythematosus in the overall population, and the stock closed down 56.6 percent at $9.47. The company is taking a biomarker defined subgroup story to regulators for Phase 3.
| Item | Detail (Alumis release) |
|---|---|
| Design | Phase 2b, 408 patients, moderate to severe autoantibody positive SLE, three doses vs placebo, 48 weeks |
| Primary endpoint | BICLA response at week 48: not met in the overall population |
| Subgroup | Interferon gene signature high patients showed robust responses on BICLA and on CLASI-50, SRI-4, and LLDAS; effect sizes not published |
| Safety | Generally well tolerated, no new signals |
| Pharmacodynamics | Dose dependent target engagement, maximal at 40 mg twice daily |
| Next step | Engage regulators on Phase 3 in the interferon high population |
The interferon gene signature divides lupus patients by how strongly type I interferon pathways are switched on. A Phase 3 restricted to that population is a smaller commercial prize bought with a cleaner biological bet, and it will need the subgroup effect to be prespecified rather than rescued after the fact. Volume in ALMS ran near twenty times the prior session.
What is GSK’s mRNA flu vaccine plan?
GSK will start a Phase 3 trial this month for FLUm3HA.b-3NA, an mRNA influenza vaccine targeting both hemagglutinin and neuraminidase, after Phase 2 results in 971 adults that GSK says produced higher immune responses than standard dose and high dose comparators in younger and older adults respectively. GSK published no figures; detailed data were presented September 1 at the Options XIII influenza conference.
The competitive wrinkle is the neuraminidase component. Moderna already holds approval for mFlusiva, a three antigen hemagglutinin mRNA vaccine, and per Fierce Biotech previously paused its own hemagglutinin plus neuraminidase candidates during a pipeline review. If the NA component adds protection in Phase 3, GSK has a differentiation story; if not, Moderna kept its lead without the extra complexity. Moderna shares closed up 9.9 percent at $154.27, market data with no cause assigned.
What is the latest on the Boston Scientific cyberattack?
Boston Scientific posted its first update in two days on September 1 at 8:44 pm ET: the incident still limits manufacturing on certain systems, but the company is “expeditiously working towards partial restoration for the shipping of some products this week” and says confidence is increasing. There has been no indication of unauthorized activity since August 25, cloud systems remain unaffected, and electronic order intake continues with orders queued for future fulfillment. The company has not quantified the financial impact and has not characterized the incident as ransomware.
| Date | Update |
|---|---|
| Aug 25 | Incident identified; last date of any detected unauthorized activity |
| Aug 26 | Initial disclosure; global disruption to ordering and shipping |
| Aug 27 to 29 | Daily updates; on premise systems only, cloud unaffected |
| Aug 30 | Manufacturing impact disclosed; partial shipping restoration targeted for week of Aug 31 |
| Sept 1, 8:44 pm ET | Partial shipping restoration still targeted for this week, confidence increasing; EDI intake continues |
How did Tuesday’s stocks close?
Exchange closes, August 31 to September 1. Moves carry no assigned cause unless a company disclosure states one.
| Ticker | Aug 31 | Sept 1 | Move |
|---|---|---|---|
| NVS | $152.06 | $161.25 | +6.0% |
| ALMS | $21.81 | $9.47 | −56.6% |
| MRNA | $140.34 | $154.27 | +9.9% |
| GSK | $50.25 | $50.66 | +0.8% |
| BMY | $66.81 | $66.92 | +0.2% |
| BSX | $48.30 | $48.08 | −0.5% |
| AMLX | $33.75 | $33.81 | +0.2% |
| NVAX | $9.37 | $10.12 | +8.0% |
| CAPR | $9.91 | $10.01 | +1.0% |
| JAZZ | $250.68 | $243.71 | −2.8% |
Novartis carried two major stories on the same day, the REMODEL wins and the CAR T halt, so its 6.0 percent gain gets no single cause assigned here. Amylyx closed at $33.81, a third consecutive close below its $35.50 offering price, with the closing of the $500.2 million offering still unannounced as of the evening of September 1 based on a check of the company’s press release index.
Frequently asked questions
What is rapcabtagene autoleucel?
Rapcabtagene autoleucel, or rap-cel (YTB323), is a Novartis autologous CD19 directed CAR T cell therapy made on the T-Charge rapid manufacturing platform. It was in eight autoimmune trials, now paused, and continues in oncology studies.
What is IEC-HS?
Immune effector cell associated hemophagocytic syndrome is a severe systemic hyperinflammatory reaction that can follow CAR T infusion, in which expanding engineered T cells trigger runaway immune activation. It caused the three deaths in the Novartis autoimmune program, per company statements reported by trade press.
How many patients died in the Novartis CAR T trials?
Three, according to Novartis statements reported by Fierce Biotech, BioSpace, and Bloomberg. Novartis has not issued a standalone press release, so there is no primary company document with the figure as of the evening of September 1.
Is Novartis’s cancer CAR T program affected?
No. The oncology studies of rapcabtagene autoleucel in chronic lymphocytic leukemia, diffuse large B cell lymphoma, and acute lymphoblastic leukemia continue, per the company’s statements.
What is zola-cel?
Zolacabtagene autoleucel (BMS-986353) is Bristol Myers Squibb’s autologous CD19 directed CAR T for autoimmune disease, made on the NEXT T rapid manufacturing platform. BMS paused enrollment after transient and reversible inflammatory events, with no deaths reported.
What is SIM0660?
SIM0660 is a preclinical trispecific antibody from Simcere Zaiming targeting CD79a, CD19, and CD3. It recruits a patient’s own T cells to deplete B cells, including in patients previously treated with CD20 or CD19 directed therapies, and is aimed at B cell mediated diseases including autoimmune conditions.
How much did Roche pay for SIM0660?
Roche paid $75 million upfront for exclusive global rights, with total potential payments up to $1.53 billion plus tiered royalties reaching double digits, per Simcere Zaiming’s September 1 release. The upfront is about 4.9 percent of the headline value.
What is a T cell engager?
A T cell engager is an antibody with one arm that grabs CD3 on a patient’s T cells and one or more arms that grab a target on the cells to be killed. Unlike CAR T, it is an off the shelf drug whose dose can be adjusted or stopped.
Did remibrutinib show liver problems in the MS trials?
No. Novartis reported no liver safety concerns and zero cases meeting Hy’s law criteria in REMODEL-1 and REMODEL-2, with a profile consistent with the chronic spontaneous urticaria program covering more than 4,500 participants.
When will remibrutinib MS data be presented?
Novartis will present detailed REMODEL results as a late breaker at MSToronto2026 and plans global regulatory submissions. The September 1 release contains no relapse rate figures.
What is the interferon gene signature in lupus?
It is a blood based measure of how strongly type I interferon driven genes are expressed. Alumis reported that interferon signature high patients responded robustly to envudeucitinib while the overall LUMUS population missed, and plans a Phase 3 focused on that subgroup.
Did Alumis’s lupus trial fail?
The Phase 2b LUMUS trial missed its primary BICLA endpoint at week 48 in the overall population of 408 patients. Alumis reported robust responses in the interferon signature high subgroup and will discuss a Phase 3 in that population with regulators.
When does GSK’s Phase 3 mRNA flu trial start?
This month, September 2026, using FLUm3HA.b-3NA, which targets both hemagglutinin and neuraminidase. Phase 2 in 971 adults showed higher immune responses than licensed comparators, per GSK, which did not publish figures.
Is Boston Scientific shipping products again?
Partially, in progress. As of the September 1 update the company was working toward partial restoration of shipping for some products this week, with electronic order intake continuing and orders queued. Manufacturing on certain systems remains affected.
Did Amylyx close its $500.2 million offering?
No closing announcement had appeared as of the evening of September 1 based on the company’s press release index. The offering priced August 19 at $35.50 with closing expected on or about August 21. AMLX has now closed below the offer price three sessions running.
Sources
Primary sources: Simcere Zaiming press release via PR Newswire (September 1, 2026); Novartis REMODEL-1/-2 press release (September 1, 2026); Alumis LUMUS topline press release via GlobeNewswire (September 1, 2026); Boston Scientific newsroom incident updates (August 26 through September 1, 2026); Amylyx press release index (checked September 1, 2026).
Trade press and other reporting: Fierce Biotech (Novartis and BMS CAR T pauses; Roche and Simcere deal; GSK mRNA flu Phase 3; ArsenalBio layoffs); BioSpace (CAR T pauses; ArsenalBio, 99 employees); Bloomberg (Novartis pause); William Blair analyst commentary as cited by Fierce Biotech and BioSpace.
Market data: Exchange closes for August 31 and September 1, 2026. No cause assigned to any move without a company disclosure.
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