Bluebird Bio Has Serious Cash Flow Concerns; Inability To Strike Reimbursement Deals In Europe Partly To Blame Bluebird bio's exit from Europe last year signals rough seas ahead for gene therapy developers, who are trying to gain market access for their products. Evidently, bluebird bio couldn’t strike deals with European payers for its EMA-approved gene therapies, Zynteglo (beti-cel) and Skysona (eli-cel).