Clinical Report: Promising Phase 1 Results for In Vivo CAR T Therapies

Overview

Recent phase 1 trials demonstrate significant efficacy of in vivo CAR T therapies, with Legend Biotech's LB2501 achieving complete responses in five out of six patients with B-cell malignancies. Additionally, Kelonia Therapeutics' in vivo BCMA CAR T therapy showed complete disease elimination in all 18 patients with relapsed or refractory multiple myeloma.

Background

The development of in vivo CAR T therapies represents a significant advancement in the treatment of hematologic malignancies, potentially simplifying the manufacturing process and improving patient outcomes. Current CAR T therapies require complex ex vivo processing, which can limit accessibility and increase costs. The promising results from recent trials highlight the potential for in vivo approaches to enhance efficacy while minimizing adverse effects.

Data Highlights

Key Findings

• LB2501 achieved a 83% complete response rate in a phase 1 trial for B-cell malignancies.
• All 18 patients treated with Kelonia's in vivo BCMA CAR T therapy showed no signs of disease one month post-treatment.
• Only one patient required intervention for cytokine release syndrome after receiving LB2501.
• Dual CAR T therapy has enabled kidney transplants in patients previously deemed incompatible.
• Engineering CAR T cells with CCR7 improved their migration and efficacy against lymphoma in preclinical models.

Clinical Implications

The findings from these trials suggest that in vivo CAR T therapies may provide effective treatment options for patients with hematologic malignancies while reducing the burden of complex manufacturing processes. Clinicians should consider the potential of these therapies in their treatment plans, particularly for patients with limited options.

Conclusion

In vivo CAR T therapies are showing promising early results, indicating a potential shift in the treatment landscape for hematologic malignancies. Continued research and longer-term follow-up will be essential to fully understand their efficacy and safety profiles.

Related Resources & Content

1. The Medicine Maker, 2026 -- This Week’s CGT News: Lilly’s $7B In Vivo CAR-T Bet
2. The Medicine Maker, 2026 -- This Week’s CGT News: CAR-T Breaks New Ground in Alzheimer’s
3. The ASCO Post, 2026 -- Early Findings From First Human Study of In Vivo CAR T in Myeloma
4. PubMed, 2025 -- Large B-cell lymphoma (LBCL): EHA Clinical Practice Guidelines for diagnosis, treatment, and follow-up
5. Franklin / MDSpire — Current Ex Vivo CAR-T Benchmarks Define the Bar for Emerging In Vivo CRISPR-Based T Cell Engineering
6. In vivo chimeric antigen receptor (CAR)-T cell therapy | Nature Reviews Drug Discovery
7. Large B-cell lymphoma (LBCL): EHA Clinical Practice Guidelines for diagnosis, treatment, and follow-up - PubMed