Atara Biotherapeutics, Inc. Q2 FY2021 earnings call

• Tab-cel: Aligned with FDA on comparability methodologies for BLA submission, provided data on nearly all tab-cel lots, planning to submit BLA in Q1 2022; made progress in Europe with MAA submission for EBV positive PTLD in November 2021. • ATA188: Important new data including MTR imaging and two-year clinical data to be presented at ECTRIMS in October; progressing with Phase 2 EMBOLD study. • CAR T programs: ATA2271 and ATA3271 in partnership with Bayer, ATA2271 to present Phase 1 data in Q4 2021; ATA3219 to submit IND in Q1 2022. • Financials: Cash burn in Q2 was $61.8 million, ended Q2 2021 with $373.4 million in cash, funded into 2023.

No specific financial performance by product segments with absolute revenue and contribution % provided in the transcript.

• Plan to submit tab-cel BLA in Q1 2022, with US launch in second half of 2022. • ATA188: Interim analysis of Phase 2 study in first half of 2022. • CAR T: ATA2271 Phase 1 data in Q4 2021; ATA3271 IND submission in second half of 2022; ATA3219 IND submission in Q1 2022.

• Uncertainties in FDA review process potentially delaying tab-cel BLA submission. • Dependence on successful regulatory approvals for product launches and commercialization.

Q: John Newman asks about Type B meeting timing and ALLELE data duration.

A: Jakob Dupont responds that Type B meetings will occur within the next two months and the Q2 ALLELE data cut is sufficient for BLA submission.

Q: Jonathan Miller asks about response duration and IND timelines.

A: Jakob Dupont explains on response duration criteria and IND gating factors as refined manufacturing timelines.

Q: Salim Syed asks about MTR and FDA use as biomarker.

A: AJ Joshi talks about MTR correlation with myelination and potential biomarker use in future discussions.

Q: Phil Nadeau asks about comparability differences and Q1 filing.

A: Jose Vidal explains comparability differences (virus source and manufacturing place) and Jakob Dupont states confidence in data package for FDA review.

Q: Matt Phipps asks about Type B meetings and MTR data.

A: Pascal Touchon and AJ Joshi respond on meeting timeline and MTR data collection in Phase 1 study.

Q: Ben Burnett's question (via Kylie Brisa) about ATA2271 and ATA3219.

A: Jakob Dupont answers on ATA2271 Phase 1 data plans and ATA3219 preclinical data availability from ASH 2020 presentation