Tabelecleucel BLA Resubmitted to FDA for EBV-Positive PTLD

The biologics license application (BLA) for tabelecleucel (tab-cel; Ebvallo) has been resubmitted to the FDA for the treatment of patients with relapsed/refractory Epstein-Barr virus (EBV)–positive post-transplant lymphoproliferative disease (PTLD), according to a news release from Atara Biotherapeutics.¹ The BLA was resubmitted by Atara’s partner, Pierre Fabre Pharmaceuticals (PFP), which holds the application. Atara stated it anticipates providing a revised Prescription Drug User Fee Act (PDUFA) target action date as it becomes available.

What does the tabelecleucel resubmission include?

PFP, with Atara’s support, resubmitted the BLA based on feedback received from a Type A meeting with the FDA held in April 2026. The resubmission includes an updated data package with additional patients and longer follow-up from the ongoing pivotal phase 3 ALLELE study (NCT03394365) of tab-cel in adults and children 2 years of age and older with relapsed/refractory EBV-positive PTLD following solid organ transplant (SOT) or hematopoietic cell transplant (HCT). The resubmission also includes supplemental data from the expanded access programs, a separate clinical study, and commercial experience in Europe.

“We are grateful to the agency for their continued guidance and engagement with our partner, PFP, and us,” said Cokey Nguyen, PhD, president and chief executive officer of Atara, in the news release.¹ “We will continue to support PFP as it prepares for the review process and anticipate providing a revised anticipated PDUFA date as it becomes available.”

What is the regulatory history of tabelecleucel in the US?

Previously, the FDA issued a complete response letter (CRL) for tabelecleucel in January 2026, in which the agency stated that findings from the ALLELE trial were no longer sufficient to support accelerated approval because the study’s design, conduct, and analysis confounded its interpretability.² The agency identified no safety issues and noted that developers had satisfactorily resolved the Good Manufacturing Practices issues cited in a prior CRL. That CRL followed an earlier CRL in January 2025 that primarily related to observations at a third-party manufacturing facility.³ A subsequent clinical hold on the investigational new drug application was later lifted in May 2025, and the FDA accepted and granted priority review to a resubmitted BLA in July 2025.^4,5 Additionally, tab-cel has received orphan drug designation and was granted breakthrough therapy designation at the time the ALLELE primary data were submitted.

What did the ALLELE trial show?

In the international, open-label, multicenter phase 3 ALLELE trial, patients received tabelecleucel at 2.0 × 10⁶ cells/kg intravenously on days 1, 8, and 15 of each approximately 5-week cycle, with the primary end point of overall response rate (ORR). Among all patients (n = 75), the ORR was 50.7% (95% CI, 38.9%-62.4%), including complete responses in 28.0% and partial responses in 22.7%.⁶

The ORR was 50.0% among 26 patients with prior HCT and 51.0% among 49 patients with prior SOT. At 12 months, the overall survival (OS) rate was 55.7% among all patients, 78.7% in those with a response, and 28.2% in those without a response; the median OS was 18.4 months (95% CI, 5.7-not evaluable [NE]) overall, NE (95% CI, 18.6 months-NE) in responders, and 3.7 months (95% CI, 1.8-11.0) in nonresponders.

Treatment-emergent serious adverse effects occurred in 62.7% of patients, including 8.0% that were related to treatment, with no instances of tumor flare reactions, infusion-related reactions, cytokine release syndrome, or immune effector cell–associated neurotoxicity syndrome reported.

References

1. Atara Biotherapeutics reports that the tabelecleucel biologics license application has been resubmitted to the US Food and Drug Administration. News release. Atara Biotherapeutics, Inc. September 30, 2026. Accessed October 1, 2026. https://tinyurl.com/44cttxj9
2. Atara Biotherapeutics provides regulatory and business update on EBVALLO (tabelecleucel). News release. Atara Biotherapeutics. January 12, 2026. Accessed October 1, 2026. https://tinyurl.com/5h34yxtx
3. Atara Biotherapeutics provides regulatory and business update on EBVALLO (tabelecleucel). News release. Atara Biotherapeutics. January 16, 2025. Accessed October 1, 2026. https://tinyurl.com/3p9jrrtj
4. Atara Biotherapeutics provides regulatory updates on EBVALLO (tabelecleucel). News release. Atara Biotherapeutics. May 5, 2025. Accessed October 1, 2026. https://tinyurl.com/3cekvud5
5. Pierre Fabre Pharmaceuticals Inc. announces FDA acceptance and priority review of the biologics license application (BLA) for tabelecleucel for the treatment of Epstein-Barr virus positive post-transplant lymphoproliferative disease (EBV+ PTLD). News release. Pierre Fabre Pharmaceuticals. July 25, 2025. Accessed October 1, 2026. https://tinyurl.com/5hfdh7cn
6. Dierick D, Ghobadi A, Baiocchi R, et al. Updated results: multicenter open-label ph 3 study of tabelecleucel for SOT or HCT recipients with EBV+ PTLD after failure of rituximab or rituximab + chemotherapy. Presented at: 51st Annual Meeting of the European Society for Blood and Marrow Transplantation; March 30-April 2, 2025; Florence, Italy. Abstract OS17-03.