Atara Biotherapeutics to Present Recent Progress and Key Upcoming Milestones at the 42nd Annual J.P. Morgan Healthcare Conference - Seite 2

• Positive new clinical data from a combined analysis, including the first reported data from the multicohort Phase 2 EBVision trial, were presented during an oral session at the ESMO Immuno-Oncology Annual Congress
• In the pooled analysis, an ORR of 77.8% was observed in 18 central nervous system (CNS) EBV+ PTLD patients including 1 CNS EBV+ PTLD patient with no prior treatment, who achieved a complete response
• One- and two-year overall survival rates were higher in responders (85.7% and 66.7%, respectively) versus non-responders (0% and 0%, respectively)
• Tab-cel was well tolerated, with no reports of serious treatment-related fatal or life-threatening treatment-emergent adverse events (TEAEs), and no reports of serious treatment-related TEAEs of neurotoxicity, organ rejection, graft versus host disease, or tumor flare reaction of any grade
• Enrollment is continuing at sites in the potential label expansion multi-cohort Phase 2 EBVision trial evaluating new patient populations, including 1L EBV+ PTLD and EBV+ immunodeficiency-associated lymphoproliferative diseases (IA-LPDs)

CAR-T Programs (Hematological Malignancies and Autoimmune Conditions)

ATA3219

• Atara is progressing development of ATA3219, an allogeneic, off-the-shelf CAR T targeting CD19, optimized for a memory phenotype and incorporating a next generation 1XX signaling domain
• Pre-clinical data support a potential best-in-class profile with longer persistence and superior anti-tumor efficacy compared to an autologous CD19 CAR T benchmark
• Site selection and activation is ongoing for the Phase 1 study in relapsed/refractory B-cell non-Hodgkin’s lymphoma (NHL) and progressing toward enrolling the first patient in Q1 2024
• Preliminary clinical data in lymphoma anticipated H2 2024
• Planned Q1 2024 IND submission in Lupus Nephritis following compelling clinical results from autologous CD19 CAR T academic clinical study showing 8/8 patients attaining remission¹
• Atara’s EBV CAR T cells may offer a differentiated therapeutic approach—off-the-shelf accessibility, no requirement for gene editing, and a less differentiated phenotype driving cellular fitness—with the potential for rapid and deep B-cell depletion
• ATA3219 autoimmune development is building upon the favorable safety profile of Atara's allogeneic EBV T cells in autoimmune disease

ATA3431