Vivacta Bio Unveils Promising Data for GT801 at 2025 ASH Meeting

Vivacta Bio has announced encouraging preliminary results from a first-in-human study of GT801, a novel in vivo CAR-T therapy, specifically targeting Non-Hodgkin’s Lymphoma (NHL). This update was shared during an oral presentation at the 2025 American Society of Hematology (ASH) Annual Meeting held in Orlando, Florida, on December 6, 2025.

In this innovative study, Dr. Pin Wang, Chief Scientific Officer of Grit Biotherapeutics, presented findings that highlighted the potential of GT801 to transform CAR-T treatment delivery. The therapy utilizes a T-LNP/mRNA platform that targets CD19, aiming to reshape the landscape of CAR-T therapies for oncology and autoimmune diseases.

Study Overview and Results

The Phase 1 study, which is investigator-initiated, focuses on evaluating the safety, tolerability, and preliminary efficacy of GT801 in patients with relapsed or refractory CD19-positive B-cell malignancies. As of the cutoff date of November 30, 2025, two patients with NHL had undergone multiple administrations of GT801 without the need for lymphodepleting chemotherapy. This aspect of the treatment is particularly noteworthy as it demonstrates the feasibility of generating functional CAR-T cells in vivo without cytotoxic conditioning.

Patient 1 received three doses of 0.5 mg, while Patient 2 received four doses of 1.5 mg. The results indicated that GT801 was generally well tolerated across both patients. High CAR expression was observed within circulating T cells, and durable CAR-T expansion occurred following each administration. Notably, researchers did not detect any CAR expression in peripheral blood monocytes, suggesting minimal off-target delivery and underscoring the selectivity of the T-LNP platform.

The pharmacodynamic activity of GT801 was rapid and profound, leading to significant B-cell depletion not only in peripheral blood but also across various tissues, including bone marrow and lymph nodes. By the fourth week after the final infusion, both patients achieved a partial response, as assessed by investigators.

Expert Insights and Future Directions

Dr. Yarong Liu, Founder and CEO of Vivacta Bio, expressed optimism regarding the findings, stating, “We are encouraged by the promising safety profile and compelling efficacy signals observed with GT801 in heavily pretreated NHL patients.” Liu emphasized that these initial results demonstrate GT801’s capability to generate potent CAR-T responses without requiring lymphodepleting chemotherapy. This advancement represents a significant step towards enhancing scalability, patient accessibility, and commercial viability of CAR-T therapies.

GT801 employs a unique systemically administered in vivo CAR-T approach that leverages T-cell–targeted lipid nanoparticles (T-LNPs) to deliver optimized mRNA encoding an anti-CD19 CAR. The platform integrates Grit Bio’s proprietary CLAMP (Controllable Ligand Attachment Modification and Purification) technology, which enables site-specific antibody conjugation, precise ligand density control, and selective T-cell targeting while minimizing off-target effects.

Vivacta Bio is dedicated to innovating next-generation in vivo CAR-T therapies for cancer and autoimmune diseases. By utilizing cutting-edge T-cell–targeted LNP design and advanced mRNA engineering, the company aims to simplify complex manufacturing workflows into a scalable, repeat-dose treatment paradigm that enhances global access to transformative immunotherapies.

Founded in 2019, Grit Biotherapeutics has been at the forefront of developing advanced immunotherapies. Its research focuses on tumor-infiltrating lymphocyte (TIL)-based therapies and innovative in vivo cell-therapy platforms. Grit’s lead product, GT101, is currently in pivotal Phase II studies, while GT201, the world’s first membrane-bound IL-15 complex–engineered TIL product, has received Investigational New Drug (IND) clearance in both China and the United States.

As the field of CAR-T therapies continues to evolve, the results from this study provide a promising glimpse into the future of personalized cancer treatment.