Caribou Biosciences CB-011 shows 83% CR rate in r/r myeloma at EHA
Caribou Biosciences has presented updated data from its CaMMouflage phase 1 trial of CB-011, an allogeneic BCMA-targeted CAR-T cell therapy, at the European Hematology Association Annual Meeting in Stockholm. The new readout, covering 12 BCMA-naïve patients treated at the recommended dose for expansion (RDE) of 450 million CAR-T cells, showed an 83% complete response or stringent complete response rate, 91% MRD negativity and 50% of patients maintaining a complete response or better at 15 months, with a median follow-up of 17.7 months.
The overall response rate in that cohort was 92%. The data are from a single-dose regimen, which Caribou says distinguishes CB-011 from currently available off-the-shelf approaches that require continued administration.
Trial design and safety profile
A total of 48 patients had been treated with CB-011 across the dose escalation portion of the trial as of the May 2026 efficacy cut-off. CB-011 is engineered with a B2M knockout and insertion of a B2M-HLA-E-peptide fusion protein, a strategy Caribou describes as immune cloaking, intended to reduce rejection of the allogeneic product by the host immune system. The FDA has granted CB-011 Regenerative Medicine Advanced Therapy, Fast Track and Orphan Drug designations.
The safety read across all 48 patients was notable for the absence of graft-versus-host disease and several other immune effector cell-associated toxicities associated with allogeneic cell products. In patients treated with the selected lymphodepletion regimen, there was one CB-011-related death attributed to immune effector cell-associated haematotoxicity. In the 12-patient RDE cohort, one patient experienced grade 3 or higher cytokine release syndrome, five experienced grade 3 or higher prolonged cytopenias, and there were no cases of grade 3 or higher neurotoxicity.
Caribou also presented a case study of a 71-year-old patient who had received eight prior lines of therapy, including ciltacabtagene autoleucel, an approved autologous CAR-T. That patient achieved a complete response at day 28 that remained ongoing at the data cut-off, a result that will attract attention given the difficulty of retreating BCMA-exposed patients.
Market context and competitive positioning
Binod Dhakal, professor of medicine at the Medical College of Wisconsin and a CaMMouflage investigator, noted that only around 10% of multiple myeloma patients currently receive autologous CAR-T therapy. Manufacturing timelines, cost and patient fitness are the principal barriers. Off-the-shelf allogeneic products have long been proposed as a structural solution to those access constraints, though earlier-generation programmes struggled to demonstrate durable responses before immune rejection curtailed activity.
The allogeneic CAR-T space in haematology remains competitive. Several programmes from companies including Allogene Therapeutics and other academic and commercial groups are in various stages of clinical development, targeting multiple myeloma and other blood cancers. Durability at 15-plus months, if confirmed in the broader dose expansion cohort, would represent a meaningful differentiator; most prior allogeneic data have shown shorter response durations. The arrival of initial dose expansion data, guided by the 450 million cell RDE, in the second half of 2026 will be the key event to watch. Those data will include both BCMA-naïve and BCMA-exposed patients and will provide a broader picture of CB-011's activity profile ahead of any potential pivotal programme.
Rachel Haurwitz, Caribou's president and chief executive, said the results "reinforce CB-011's potential as a single-dose, off-the-shelf approach that could meaningfully expand access to cellular therapies and change the treatment paradigm" for relapsed or refractory multiple myeloma patients.