Atara Biotherapeutics is a clinical-stage biopharmaceutical company that has effectively wound down its operations and now functions primarily as a royalty and milestone vehicle. Atara's sole meaningful asset is tab-cel (Ebvallo), an allogeneic, off-the-shelf EBV-specific T-cell therapy for EBV-associated post-transplant lymphoproliferative disease (EBV+ PTLD), a rare and often fatal cancer in immunocompromised transplant patients who fail first-line therapy. Ebvallo is approved in the EU, UK, and Switzerland, but has faced significant setbacks in the U.S., where the FDA has issued two Complete Response Letters — one related to manufacturing compliance and a second questioning the adequacy of the pivotal trial design. Atara has transferred all manufacturing, clinical, development, and regulatory responsibilities for tab-cel to its commercial partner Pierre Fabre, retaining rights to milestones (up to $864M in total remaining) and significant double-digit tiered royalties on global net sales. A portion of these receipts is owed to royalty financing partner HCRx before Atara sees cash flow. With roughly 80-90% of staff cut across four rounds of layoffs in 2025, Atara now has just 14 employees. Atara's board is actively exploring strategic alternatives, including a sale or merger. The company's value hinges almost entirely on Pierre Fabre securing FDA approval for tab-cel and Atara's ability to execute a strategic transaction.