LB2501 is a first-in-class, replication-incompetent lentiviral vector engineered to selectively transduce T cells in vivo and generate CD19/CD20 dual-targeting CAR-T cells directly within patients. Unlike conventional CAR-T therapies, LB2501 is administered as a single intravenous infusion and does not require ex vivo cell manufacturing or lymphodepleting chemotherapy.

The ongoing Phase I study enrolled heavily pretreated patients with relapsed/refractory B-cell NHL who had progressed after at least two prior lines of therapy.

Safety Outcomes-

• Infusion-related reactions occurred in 9 patients (75.0%); all were Grade 1 or 2, resolved within a median of 2.0 days, and required no tocilizumab or glucocorticoids. 

• Cytokine release syndrome occurred in 66.7% patients (Grade 1 in 58.3%, Grade 2 in 8.3%).

• No neurotoxicity (ICANS) was observed. 

• Grade≥3 LVV-related and CAR-T-related adverse events were limited to decreased lymphocyte count (33.3% each) and decreased neutrophil count (25.0% and 50.0%, respectively).

KOL Insights-

“The early clinical experience with LB2501 is highly encouraging and represents an important step toward the next generation of CAR-T cell therapy. The depth of responses achieved with a single infusion across treated patients highlights the potential of this platform to further enhance cellular therapy outcomes. Building on the strong scientific and commercial foundation established with CARVYKTI, these findings provide confidence in the feasibility of advancing innovative CAR-T delivery approaches and support continued clinical development of LB2501.”– Expert Opinion

“The responses observed at the higher dose level achieved a 100% objective response rate, together with a favorable safety profile and the absence of lymphodepletion, support further investigation of LB2501 as a novel in vivo CAR-T approach. The additional pharmacokinetic and translational findings presented at EHA further support the feasibility of generating CAR-T cells directly within the patient.”– Expert Opinion

Conclusion-

Non-Hodgkin lymphoma (NHL) accounts for approximately 4–5% of all cancers globally, with diffuse large B-cell lymphoma representing the most common aggressive subtype. Although CAR-T therapies have transformed outcomes for relapsed/refractory B-cell malignancies, their adoption remains constrained by manufacturing complexity, prolonged vein-to-vein times, high costs, and the need for lymphodepletion.

The first-in-human Phase I study of LB2501 introduces a novel therapeutic paradigm by enabling direct in vivo generation of CD19/CD20 dual-targeting CAR-T cells following a single intravenous infusion. Early results demonstrated impressive clinical activity, including a 100% objective response rate and 83.3% complete response rate at DL2, alongside a favorable safety profile characterized by low-grade CRS, absence of neurotoxicity, and no treatment-related serious adverse events. While longer follow-up and larger patient cohorts are required, LB2501 provides the first clinical evidence that in vivo CAR-T therapy may offer a scalable, readily accessible, and potentially practice-changing alternative to traditional ex vivo CAR-T approaches in B-cell malignancies.