Novartis and BMS Halt Autoimmune CD19 CAR-T Trials Due to Deaths and Inflammatory Toxicity
Safety Signals and Trial Halt
Novartis (NVS) halted screening, randomization, and dosing in eight autoimmune and neuroimmune disease trials of its autologous CD19-targeting CAR-T, rapcabtagene autoleucel (rap-cel, YTB323), on August 24, 2026. The decision followed three cases of immune effector cell-associated hemophagocytic syndrome (IEC-HS) and the subsequent deaths of three patients. The affected conditions included systemic lupus erythematosus (SLE), lupus nephritis, myasthenia gravis, and multiple sclerosis. The Phase 2 AUTOGRAPH study (NCT06581198) for SLE and lupus nephritis, involving 179 patients, is now under significant strain, impacting mid-stage development timelines and patient recruitment beyond exploratory trials.
BMS Program and Manufacturing Controversy
Bristol Myers Squibb (BMY) voluntarily halted enrollment in its autologous CD19 CAR-T, zolacabtagene autoleucel (zola-cel, BMS-986353), after observing transient and reversible inflammatory events. Zola-cel is a Phase 1-focused program using the CD19 CAR structure of the approved Breyanzi and the next-generation NEX-T rapid manufacturing process. The Breakfree-1 trial previously reported one IEC-HS case. While both rap-cel's T-Charge and zola-cel's NEX-T were designed to shorten culture time and enhance in vivo expansion, rapid cell expansion appears to pose inflammatory toxicity risks in autoimmune patients with heightened immune activity. This suggests the need for independent validation of CAR structure, cell composition, dosing, manufacturing duration, and patient selection.
Competitive Landscape and Differentiation Criteria
Kyverna Therapeutics (KYTX)'s mivocabtagene autoleucel (miv-cel, KYV-101), a fully human CD19 CAR-T with a CD28 costimulatory domain, reported no high-grade cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), or clinical hold signals. The candidate is in sequential BLA submission for ankylosing spondylitis and Phase 3 for generalized myasthenia gravis, positioning it as a frontrunner in the race for the first autoimmune CAR-T approval. Cabaletta Bio (CABA)'s resecabtagene autoleucel (rese-cel, CABA-201), a CD19 CAR-T using a traditional 9-day manufacturing process, is advancing in the Phase 1/2 RESET program and late-stage myositis trials, citing no IEC-HS cases as a key differentiator. Allogene Therapeutics (ALLO), CRISPR Therapeutics (CRSP), and Fate Therapeutics (FATE), which are pursuing allogeneic approaches, are also competing with off-the-shelf therapies featuring reduced inflammatory cell composition.
Market, Regulatory, and Standard of Care Context
The global SLE market is projected to grow from USD 3.71 billion in 2026 to USD 5.32 billion in 2031. However, CAR-T therapies must compete with lower toxicity standards set by established treatments such as Benlysta (belimumab, BLyS inhibitor), Saphnelo (anifrolumab, IFNAR1 inhibitor), and Lupkynis (voclosporin, calcineurin inhibitor) for lupus nephritis. The FDA approved Benlysta on March 9, 2011, Saphnelo on August 2, 2021, and the subcutaneous pen version of Saphnelo on April 27, 2026. Rap-cel and zola-cel remain in pre-approval stages for autoimmune indications, with no AdComm meetings held. Novartis is currently reviewing safety data with regulatory authorities. Unlike oncology, where life-threatening conditions justify aggressive therapies, chronic autoimmune diseases with lower mortality require long-term remission without treatment. However, the three IEC-HS-related deaths significantly raise the risk-benefit threshold for CAR-T in this context.
In the short term, the halt of Novartis' eight trials, including the Phase 2 rap-cel study, and the enrollment suspension of BMY's Phase 1 zola-cel program will increase clinical timelines, safety monitoring costs, and valuation discounts for autoimmune CAR-T. In the medium to long term, Kyverna's miv-cel BLA and Phase 3 myasthenia gravis program, along with Cabaletta's rese-cel late-stage myositis trial, will serve as key benchmarks for evaluating the risk differences between rapid manufacturing platforms and traditional processes. In the USD 3.71 billion SLE market in 2026, CAR-T's potential for single-dose administration and drug-free remission could offer economic advantages over the standard of care involving repeated dosing with Benlysta, Saphnelo, and Lupkynis. However, the three IEC-HS-related deaths are likely to shift the regulatory competitive landscape, making patient selection, cell composition, dosing, and toxicity response protocols critical assets. Going forward, manufacturing and clinical execution capabilities, rather than platform-wide innovations, are expected to determine success among companies in the autoimmune CAR-T space.
Source: BioPharma Dive (rss)