Legend Biotech reports 100% ORR in Phase 1 in vivo CAR-T NHL trial
Legend Biotech has disclosed early Phase 1 data for LB2501, its investigational in vivo CAR-T therapy targeting both CD19 and CD20, ahead of a late-breaking oral presentation at the European Hematology Association (EHA) Congress in Stockholm on 14 June. The readout, from an ongoing first-in-human study in relapsed/refractory B-cell non-Hodgkin lymphoma (R/R B-NHL), showed a 100% objective response rate (ORR) and an 83.3% complete response rate in the six patients enrolled at dose level 2, with all responses ongoing at the April 2026 data cutoff.
The trial enrolled 12 patients across two dose cohorts. Median follow-up for the higher dose level was 2.2 months — short enough that durability conclusions cannot yet be drawn — but the pharmacokinetic data showed CAR-T cells persisting in peripheral blood for up to 116 days, suggesting sustained in vivo expansion. Crucially, LB2501 is designed to generate CAR-T cells directly inside the patient after a single intravenous infusion, removing the need for the ex vivo cell manufacturing and lymphodepleting chemotherapy that define conventional CAR-T protocols.
Safety and platform mechanics
The safety profile reported was notably clean for a CAR-T programme. No dose-limiting toxicities, serious adverse events, or deaths were observed. Cytokine release syndrome occurred in 66.7% of patients but was confined to Grade 2 or below, and no cases of immune effector cell-associated neurotoxicity syndrome (ICANS) were reported — a meaningful marker given that ICANS has been a persistent concern with approved ex vivo CAR-T products. Infusion-related reactions were common (75% of patients) but similarly mild. Grade 3 or above adverse events were limited to lymphocyte and neutrophil count reductions, consistent with the therapy's mechanism.
LB2501 is built on Legend's proprietary TaVec lentiviral vector platform, which the company says is engineered for T-cell specificity and to restrict transduction of non-T cells — a design intended to reduce off-target genotoxicity risk that has been a central regulatory concern for in vivo gene-delivery approaches.
Market context and competitive landscape
The in vivo CAR-T space is one of the more contested frontiers in cell and gene therapy. A handful of companies, including Umoja Biopharma and several academic spin-outs, are pursuing lentiviral vector-based in vivo approaches, while others — notably Interius BioTherapeutics — are exploring adeno-associated viral vectors. The appeal of the modality is straightforwardly economic and logistical: removing the apheresis and manufacturing steps could dramatically reduce the cost and complexity that have constrained uptake of approved ex vivo CAR-T products such as Legend's own CARVYKTI in multiple myeloma.
That context matters for reading these results. B-NHL is already served by several approved ex vivo CD19-targeted CAR-Ts, including axicabtagene ciloleucel and lisocabtagene maraleucel. The dual CD19/CD20 targeting of LB2501 is positioned to address antigen escape — a recognised mechanism of resistance — though clinical evidence that this dual approach improves durable remission rates over CD19 alone remains to be established in a larger, longer-follow-up dataset. The EHA presentation on 14 June will be the first opportunity for the haematology community to scrutinise the full data package, including dose level 1 results not yet disclosed in the abstract.
Legend Biotech, which employs over 3,000 people and markets CARVYKTI with Johnson & Johnson, said it intends to continue enrolment and provide further updates as the Phase 1 study matures. Investors will be watching for an indication of the regulatory pathway and any signals on whether a pivotal study design is under discussion with the FDA or EMA.