Galapagos Snags FDA RMAT Designation for R/R Mantle Cell Lymphoma CAR T-Cell Therapy

Galapagos' GLPG5101, an investigational CD19-directed chimeric antigen receptor (CAR) T-cell therapy product, has received regenerative medicine advanced therapy (RMAT) designation from the FDA for the treatment of relapsed/refractory (R/R) mantle cell lymphoma (MCL).¹

The RMAT designation was granted based on data from patients with R/R B-cell non-Hodgkin lymphoma treated in the phase 1/2 ATALANTA-1 clinical trial (NCT06561425), which includes a subset of patients with R/R MCL. According to Galapagos, among the findings were “high objective and high complete response rates.” The safety profile was characterized as “manageable”, with rates of high-grade cytokine release syndrome and immune effector cell–associated neurotoxicity syndrome being low. The company also stated that rates of participants dropping out of the trial were also low.

“This designation reflects the promising clinical activity and safety profile observed in our ongoing phase 1/2 study and supports our commitment to delivering an effective and timely treatment option to patients in need,” Omotayo Fasan, MRCP, DTM&H, MBBS, the head of the clinical development program at Galapagos, said in a statement.¹ “With RMAT status allowing for closer collaboration with the FDA, this will enable additional opportunities for accelerated development and assessment timelines.”

Alongside the announcement of the RMAT designation, Galapagos noted that it plans to present updated data from the ongoing ATALANTA-1 trial at an unspecified future medical conference. Notably, the ATALANTA-1 trial is evaluating the feasibility and efficacy of decentralized manufacturing for GLPG5101, which is given intravenously in a single fixed dose, as a secondary objective. The study includes eligibility for 8 hematologic malignancies.

Earlier this year, Galapagos presented data from ATALANTA-1 at the European Hematology Association (EHA) 2025 Congress, held June 12 to 15, both virtually and in Milan, Italy. CGTLive® interviewed Fasan during the conference to learn more about some of the key findings presented.

Fasan highlighted that the vein-to-vein time for GLPG5101 was short, with about 9 in 10 patients receiving their infusion in the 7-day window following leukapheresis, thus not necessitating bridging therapy. For reference, he pointed out that currently available CAR T-cell products typically have a vein-to-vein time of 4 to 6 weeks. He also noted that fresh CAR T-cell product was given to 95% of the treated patients, stating that fresh CAR T-cell product circumvents the need for cryopreservation and is associated with benefits such as reduced toxicity and good expansion.

“This therapy is manufactured using Galapagos’ innovative decentralized platform, which enables delivery of fresh, stemlike early memory T-cells in a median vein-to-vein time of just 7 days...” Fasan told CGTLive. “Galapagos’ EHA results suggest a meaningful advance in CAR [T-cell] therapy delivery and safety. The decentralized, 7-day manufacturing approach demonstrates that fresh, early memory CAR T cells can be reliably delivered in a decentralized manner, enhancing physician confidence and expanding treatment access—especially for patients too fragile to wait weeks for traditional CAR-T production.”

Notably, Galapagos is also tracking long-term follow-up of patients treated with GLPG5101 and several of its other CAR T-cell products through its phase 3 HESPERIA long-term follow-up study (NCT06652633).² Earlier this year, CGTLive covered the design of the HESPERIA study as part of our Clinical Trials in Progress series. The study is assessing the long-term safety and efficacy of patients treated with Galapagos CAR T-cell products over 15 years post treatment. According to the company’s pipeline page on its own website, Galapagos CAR T-cell products include GLPG5101, which is being evaluated in ATALANTA-1; GLPG5201, which is being evaluated in the phase 1/2 EUPLAGIA-1 clinical trial (CTIS: 2022-501686-47-00); and GLPG5301, which is being evaluated in the phase 1/2 PAPILIO-1 clinical trial (EU CT 2022-500782-27-00).

REFERENCES
1. Galapagos NV announces U.S. FDA regenerative medicine advanced therapy (RMAT) designation granted to GLPG5101 for the treatment of relapsed/refractory mantle cell lymphoma. News release. August 6, 2025. Accessed August 13, 2025. https://www.glpg.com/press-releases/galapagos-nv-announces-u-s-fda-regenerative-medicine-advanced-therapy-rmat-designation-granted-to-glpg5101-for-the-treatment-of-relapsed-refractory-mantle-cell-lymphoma/
2. Our pipeline. Galapagos NV. February 13, 2025. Accessed August 13, 2025. https://www.glpg.com/innovation/pipeline/