Planned 2020 Milestones – Distilling to Practice Ide-cel (bb2121) MM US BLA submission ZYNTEGLO completion of US BLA submission Lenti-D CALD EU MAA and US BLA Submissions Ide-cel (bb2121) KarMMa and CRB-401 data* LentiGlobin SCD Phase 3 HGB-210 Study Start Lenti-D ALD-102 data update Zynteglo Phase 3 (HGB-207 and HGB-212) data LentiGlobin SCD HGB-206 data and regulatory update ZYNTEGLO first commercial patients treated ZYNTEGLO QTC and Sick Fund contracts in place ZYNTEGLO Access and Reimbursement in additional EU countries established ZYNTEGLO and ide-cel US Launch Ready 1-2 New INDs CASH RUNWAY INTO SECOND HALF 2021 SECOND HALF 2020 FIRST HALF 2020 Regulatory Submissions Clinical Updates Commercial and Foundation Building *submission for data presentation planned in H1:20 Exhibit 99.1

T H E G E N E T H E R A P Y P R O D U C T S C O M P A N Y LentiGlobin SCD LentiGlobin TDT Lenti-D CALD Ide-cel (bb2121) Multiple Myeloma Products on the Market 4 INDs Per Year Beginning 2020 1-2 Clinical Programs 5+ bluebird 2022 Vision – The Leading Cell and Gene Therapy Company Patient Impact ∞ A Bold Vision in 2019 1: Many translational engine delivering Launched/ Submitted Launched with label expansions Launched Launched and heading towards earlier line approvals A Bold Vision in 2019… Becoming Even Bolder in 2020