Immatics PRAME TCR Therapy Yields Six-Month Remission in Pediatric Nephroblastoma
A 17-year-old with advanced nephroblastoma and lung, liver and brain metastases received a PRAME-directed TCR therapy after all options failed and achieved deep remission with marked tumor regression. Remission persists at six months with PET, MRI and liquid biopsy showing no detectable disease.
1. Patient Background and Disease Profile
A 17-year-old adolescent presented with PRAME-positive advanced nephroblastoma characterized by a 16 cm abdominal lesion and metastases to the lung, liver and brain. Standard chemotherapy, radiation and surgical options were exhausted, rendering the case ineligible for existing clinical trials.
2. PRAME-Directed TCR Treatment
Under a named-patient use protocol, Immatics provided its IMA203CD8 PRAME-directed TCR encoded by a lentiviral vector. Autologous T cells were engineered and infused at a specialized pediatric cancer center following lymphodepletion to target PRAME-expressing tumor cells.
3. Treatment Response and Monitoring
The patient exhibited a deep anti-tumor response with remission observed three months post-infusion and sustained at six months. Imaging via PET and MRI demonstrated marked regression across all lesions, while liquid biopsy detected no tumor-derived DNA, indicating molecular remission.
4. Safety and Future Development
The only reported adverse event was manageable cytokine release syndrome, resolved with multi-modal anti-cytokine therapy and corticosteroids. Immatics is evaluating a potential first-in-pediatrics Phase 1/2 basket study in HLA-A*02:01-positive, PRAME-expressing relapsed or refractory solid tumors to expand clinical development.