On December 8, 2025 Pierre Fabre Pharmaceuticals Inc., reported updated results presented at the 67th American Society of Hematology (ASH) (Free ASH Whitepaper) Annual Meeting of the pivotal Phase 3 ALLELE study of tabelecleucel in adults and children with R/R EBV+ PTLD following HCT or SOT. The two abstracts included sub-analyses of pediatric patients and by prior therapy.
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"These two sub-analyses highlight the potential of tabelecleucel to improve outcomes for patients, both pediatric and adult, with R/R EBV+ PTLD who after undergoing a potentially life-saving solid organ or hematopoietic cell transplant suddenly face yet another life-threatening illness," said presenter and clinical investigator, Dr. Sarah Nikiforow, Assistant Professor, Stem Cell Transplantation, Dana-Farber Cancer Institute. "The updated data support the potential of tabelecleucel as an important advancement in addressing the significant unmet need for patients with EBV+ PTLD, who currently have no FDA-approved treatment options and may experience poor overall survival of only weeks to a few months following the failure of standard treatment."
ALLELE is an ongoing multicenter, open-label Phase 3 study. This analysis encompassed a larger cohort of 86 patients (29 HCT, 57 SOT). In the study, patients received a median of two treatment cycles. Each cycle of tabelecleucel consisted of three infusions given on days 1, 8 and 15 with an imaging assessment of efficacy on day 28.
The updated findings showed patients receiving tabelecleucel had an objective response rate (ORR) of 47.7% with the HCT cohort achieving an 48.3% ORR and SOT cohort achieving a 47.4% ORR. The median (95% CI) overall survival (OS) from Kaplan-Meier survival estimates for the HCT cohort was 18.6 months. For the SOT cohort, median OS was not estimable as more than half of the patients remained in follow-up. In a sub-analysis of treatment response by prior therapy in SOT patients, ORR was 52.4% for those receiving rituximab and 44.4% for those receiving rituximab and chemotherapy.
Safety findings presented were consistent with previously published data. Serious adverse events (SAEs) were reported in 58.6% of HCT and 66.7% of SOT patients. These events were related to study treatment in 1 HCT patient and 7 SOT patients. Fatal SAEs were reported in 5 HCT and 9 SOT patients, and none were reported by investigators to be treatment related. Pyrexia was reported in 1 SOT patient and considered as a potential sign of cytokine release syndrome possibly related to treatment. In the updated ALLELE study data, there were no reports of tumor flare or infusion reactions, immune effector cell-associated neurotoxicity syndrome, or transmission of infectious diseases. No events of graft vs host disease or organ rejection were reported as tabelecleucel related.
A new sub-analysis of 12 pediatric patients less than 17 years of age found the ORR was 50.0% with complete response reported in 4 of 12 patients, and partial response observed in 2 of 12 patients. Efficacy and safety observed in the pediatric sub-group was consistent with that reported in the overall population. Six patients developed treatment emergent adverse events (TESAEs); 4 TESAEs in 2 patients were considered treatment related. Fatal SAEs were reported in 2 patients, neither considered related to treatment. There were no reports of tumor flare, infusion reactions, immune effector cell-associated neurotoxicity syndrome, graft vs. host disease, transmission of infection or bone marrow/solid organ transplant rejection.
"The growing body of evidence supporting the efficacy and safety of tabelecleucel in treatment of people living with EBV+PTLD enhances our confidence in the potential of this innovative cell therapy. These patients have undergone a difficult journey to receive a life-saving transplant only to be diagnosed with this ultra rare form of cancer and they deserve an effective treatment option following failure of standard-of-care therapy," said Adriana Herrera, Chief Executive Officer of Pierre Fabre Pharmaceuticals Inc., the Pierre Fabre Laboratories pharmaceutical subsidiary in the United States. "We look forward to our FDA target action date in January 2026 and if approved, the opportunity to address the significant unmet medical need of these patients who urgently need new treatment options."
A BLA for tabelecleucel is currently under FDA review with a target action date of January 10, 2026. The application is granted priority review for tabelecleucel indicated as monotherapy for treatment of adult and pediatric patients two years of age and older with EBV+ PTLD who have received at least one prior therapy including an anti-CD20 containing regimen. The BLA is supported by pivotal study data from the ALLELE study and supportive data covering more than 430 patients treated with tabelecleucel.
About Tabelecleucel
Tabelecleucel is an allogeneic, off-the-shelf, EBV-specific T-cell immunotherapy designed to selectively target and eliminate EBV-infected cells. Unlike autologous CAR-T therapies, allogeneic T-cells are derived from third-party donors and are not genetically modified. T-cells are collected from the blood of healthy donors and activated by exposure to Epstein-Barr virus antigens, enriching for a population of T-cells that recognize EBV. These EBV-specific T-cells are then expanded, characterized, and cryopreserved for future use to treat patients.
About EBV+PTLD
EBV+ PTLD is an ultra-rare, acute, and potentially deadly blood malignancy that occurs after transplantation when patient T-cell immune responses are compromised by immunosuppression. It can impact patients who have undergone allogeneic HCT or SOT. Poor median survival of 3 weeks and 4.1 months for HCT and SOT, respectively, is reported in EBV+ PTLD patients for whom standard of care failed, underscoring the significant need for new therapeutic options.
(Press release, Pierre Fabre, DEC 8, 2025, View Source [SID1234661285])