bluebird bio’s Analyst Day Highlights Commercial Path to Patients and Research Engine Focused on Next-Generation Gene and Cell Therapies

New Collaboration with Seattle Children’s Research Institute Targets
New Immunotherapy Approaches to Acute Myeloid Leukemia

Phase 1/2 Study for Merkel Cell Carcinoma Planned with Fred
Hutchinson Cancer Research Center

Additional Preclinical Programs Across Both the Severe Genetic
Disease and Oncology Therapeutic Areas Support IND Goals

Company Will Webcast Live from the Event Beginning at 8:30 a.m. EDT

CAMBRIDGE, Mass.–(BUSINESS WIRE)–bluebird
bio, Inc. (Nasdaq: BLUE) today will host an Analyst Day in New York
that will highlight significant progress in the company’s emerging
immuno-oncology and severe genetic disease pipeline, provide updates on
launch expectations for its first gene therapy product and share key
aspects of its long-term growth strategy. The company also is announcing
a new research collaboration with Seattle Children’s Research Institute
in Acute Myeloid Leukemia (AML), a Phase 1/2 study planned in
Merkel Cell Carcinoma (MCC) with the Fred Hutchinson Cancer Research
Center and programs in Diffuse Large B-cell Lymphoma (DLBCL) and MAGE-A4
positive solid tumors.

“bluebird is at a significant inflection point, with the potential
approval and launch of our first gene therapy product this year and
submissions for regulatory approval for potentially three additional
products through 2022,” said Nick Leschly, chief bluebird. “We have the
opportunity to leverage our gene and cell therapy expertise across our
platform and enable a steep innovation curve for next-generation
products. We are fueled by what is just the beginning of our efforts to
recode the science, systems and status quo to reach new innovation
frontiers and make a significant impact on patients’ lives.”

Further strengthening its leadership position in developing
transformative first-in-class and best-in-class gene and cell therapies,
bluebird bio will discuss several key milestones and collaboration
updates across its research pipeline, which is focused on
next-generation, disruptive solutions for devastating diseases. In
addition to the two clinic-ready programs planned for 2019, the company
is on track to submit 1-2 investigational new drug applications in 2020
and beyond.

“Relentless innovation is in our DNA at bluebird. Our 1-to-Many research
strategy rapidly integrates and iterates our tools and technologies
across our core platforms of gene editing, gene addition and cellular
immunotherapy, to develop the next generation of gene and cell therapies
with the potential to improve patients’ lives,” said Philip Gregory, D.
Phil., chief scientific officer, bluebird bio. “Our research engine, in
partnership with our network of academic and industry collaborations, is
designed to take on big problems that, if successful, will disrupt our
field.”

Research highlights include:

• AML Research Collaboration with Seattle Children’s Research
  Institute: The research collaboration is intended to address two
  challenges of tackling AML, specifically the heterogeneity of the
  disease as well as the salvage of normal tissues with the potential
  for on-target/off-tumor targeting. Our T cell immunotherapy approach
  is expected to leverage technology that enables T cells to target
  multiple antigens on the surface of cancer cells as well as bluebird’s
  proprietary Dimerizing Agent Regulated Immunoreceptor Complex (DARIC)
  platform. By utilizing the DARIC platform in potential product
  candidates, we expect to be able to exert pharmacologic control of CAR
  T cell activity in vivo, allowing the investigator to switch on
  and switch off the activity of the engineered T cells in the patient
  as needed by administering a small molecule drug. Combined with
  Seattle Children’s world-class bench-to-bedside expertise in the arena
  of oncology cell therapies, the research collaboration’s goal is to
  rapidly accelerate development of potential new therapies for patients
  with AML.
• Phase 1/2 Trial for Merkel Cell Carcinoma: An academic,
  proof-of-concept phase 1/2 single-arm study evaluating Merkel Cell
  Polyomavirus (MCPyV) TCR-engineered autologous T cells in combination
  with avelumab (anti-PDL1) is FDA-approved and in the final initiation
  stages of trial approval at the Fred Hutchinson Cancer Research Center
  for the treatment of MCC, a rare neuroendocrine cancer. Exploratory
  clinical data generated by researchers at the Fred Hutchinson Cancer
  Research Center exploring patient derived MCPyV reactive T cells in
  combination with PD1 axis blockade has shown promising depth and
  durability of response. Results from the academic phase 1/2 single-arm
  study are expected to inform next-generation T cell approaches
  including TCR engineering and checkpoint inhibition.
• MAGE-A4: Through its collaboration with Medigene, bluebird has
  developed a next-generation MAGE-A4 TCR expected to enter the clinic
  for solid tumors in 2020. This co-receptor-independent TCR candidate
  has shown robust anti-tumor activity controlling tumors in a
  subcutaneous melanoma xenograft model as a single agent. Moreover,
  this highly active TCR can be combined with bluebird’s chimeric TGF-β
  receptor signal converter technology to “flip” the immunosuppressive
  signals present in the tumor microenvironment toward T cell
  stimulation and proliferation. This is the first collaboration target
  with Medigene of a potential six TCR products that the companies have
  agreed to work on together.
• Diffuse Large B-cell Lymphoma Candidate: Our DLBCL
  preclinical program builds on the knowledge gained from the current
  generation of CD19-targeting cell therapies by incorporating multiple
  next-generation technologies to potentially address both the depth and
  durability of response. Specifically, our potential DLBCL product
  candidate combines (i) dual-targeting directed to two novel antigens;
  (ii) within a unique CAR construction that is designed to enhance T
  cell activation; and (iii) gene editing for potential potency and
  durability enhancements, all in a single product candidate.
• Mucopolysaccharidosis (MPSI): Our MPSI program is focused on
  the severe form of MPSI, an ultra-rare metabolic condition that causes
  severe neurologic impairment and organ damage, also referred to as
  Hurler Syndrome. In our academic collaboration with the University of
  Minnesota, we expect to leverage key learnings from our hematopoietic
  stem cell lentiviral vector (HSC LVV) platform technology to deliver
  gene-modified cells that can potentially cross the blood-brain barrier
  and express high and sustained levels of therapeutic enzyme.
  Preclinical data in the MPS1 mouse model demonstrates full molecular
  correction of the disease across all critical organs impacted by the
  disease, including the brain, following administration of an HSC
  LVV-gene-modified stem cell product. These robust preclinical data
  support the potential clinical application of this product candidate.

Webcast

To access the live webcast of bluebird bio’s Analyst Day presentation,
please visit the “Events & Presentations” page within the Investors &
Media section of the bluebird bio website at http://investor.bluebirdbio.com.
A replay of the webcast will be available on the bluebird bio website
for 90 days following the meeting.

About bluebird bio, Inc.

bluebird bio is pioneering gene therapy with purpose. From our
Cambridge, Mass., headquarters, we’re developing gene therapies for
severe genetic diseases and cancer, with the goal that people facing
potentially fatal conditions with limited treatment options can live
their lives fully. Beyond our labs, we’re working to positively disrupt
the healthcare system to create access, transparency and education so
that gene therapy can become available to all those who can benefit.

bluebird bio is a human company powered by human stories. We’re putting
our care and expertise to work across a spectrum of disorders by
researching cerebral adrenoleukodystrophy, sickle cell disease,
transfusion-dependent β-thalassemia and multiple myeloma using three
gene therapy technologies: gene addition, cell therapy and
(megaTAL-enabled) gene editing.

bluebird bio has additional nests in Seattle, Wash.; Durham, N.C.; and
Zug, Switzerland. For more information, visit bluebirdbio.com.

Follow bluebird bio on social media: @bluebirdbio,
LinkedIn,
Instagram
and YouTube.

Forward-Looking Statements

This release contains “forward-looking statements” within the meaning
of the Private Securities Litigation Reform Act of 1995, including
statements regarding the plans for the potential commercial launch of
the Company’s product candidates, as well as the advancement of the
Company’s research and development plans. Any forward-looking statements
are based on management’s current expectations of future events and are
subject to a number of risks and uncertainties that could cause actual
results to differ materially and adversely from those set forth in or
implied by such forward-looking statements. These risks and
uncertainties include, but are not limited to, the risk that the
positive efficacy and safety results from our prior and ongoing clinical
trials of our product candidates will not continue or be repeated in our
ongoing or planned clinical trials; risks that the current or planned
clinical trials of our product candidates will be insufficient to
support future regulatory submissions or to support marketing approval
in the U.S. and EU; the risk that our collaborations with third parties
will not be successful; the risk that our planned clinical studies may
be delayed or not be initiated at all; and the risk that our product
candidates will not be successfully developed, approved or
commercialized. For a discussion of other risks and uncertainties, and
other important factors, any of which could cause our actual results to
differ from those contained in the forward-looking statements, see the
section entitled “Risk Factors” in our most recent Form 10-Q as well as
discussions of potential risks, uncertainties and other important
factors in our subsequent filings with the Securities and Exchange
Commission. All information in this press release is as of the date of
the release, and bluebird bio undertakes no duty to update this
information unless required by law.

Contacts

Investors & Media
bluebird bio
Investors:
Elizabeth
Pingpank, (617) 914-8736
[email protected]

Media:
Jenn
Snyder, (617) 448-0281
[email protected]