Tomostrocel (MSC-FFM) for steroid- or treatment-refractory pediatric aGvHD: Real-world outcomes

Results from a multicenter, retrospective, real-world study evaluating the efficacy and safety of tomostrocel, a mesenchymal stromal cell (MSC) product designed to minimize inter-donor variability, in pediatric patients (<18 years) with heavily pretreated, steroid- or treatment-refractory acute graft-versus-host disease (aGvHD) were published in Haematologica by Vogelsang et al. Data were collected from 140 treatment episodes in 139 pediatric patients who received tomostrocel between 2017 and 2025 across 34 centers. Patients received a median of 3.5 prior therapies, including ruxolitinib in 76 cases.

Key data: The overall response rate (ORR) was 62.9% (complete response [CR], 22.1%; partial response [PR], 40.7%) at Day 28 and 66.9% (CR, 44.9%; PR, 22.1%) at Day 60. In patients pretreated with ruxolitinib, the ORR was 64.5% at Day 28 and 64.9% at Day 60. The organ stage in patients with skin, liver, lower gastrointestinal (GI), and upper GI involvement improved from baseline to Day 28 in 69.4%, 57.5%, 58.6%, and 39.5% of patients, respectively. Overall survival (OS) was 64.1%, 55.1%, and 50.6% at 6, 12, and 24 months, respectively. Tomostrocel was well tolerated, with four adverse drug reactions reported in three patients. Infections occurred in 39.3% of patients, none of which were considered related to tomostrocel.

Key learning: These real-world data highlight the meaningful response rates and favorable safety profile of tomostrocel in heavily pretreated pediatric patients with steroid- or treatment-refractory aGvHD, including those previously treated with ruxolitinib, supporting its potential as a therapeutic option in this population.