Juno Therapeutics Establishes Manufacturing Presence in Washington State

SEATTLE, Feb. 9, 2015 -- Juno Therapeutics, Inc. (JUNO) today announced that it has entered into a lease agreement for a facility in Bothell, Washington to manufacture the company's cell therapy products. The facility, which is expected to come online in early 2016, will support Juno's planned JCAR015 multicenter clinical trial, additional clinical programs in Juno's pipeline, and the company's first commercial products.

"The Bothell manufacturing facility is an important milestone for Juno," said Hans Bishop, CEO and president of Juno. "The manufacturing expertise we are developing is key to our long term success, increasing our ability to run multiple clinical trials and commercialize our pipeline, and as a platform to introduce the various innovations we are investing in to optimize patient outcomes."

Washington governor Jay Inslee stated, "We are thrilled to have Juno as a part of our life science ecosystem and look forward to supporting the growth of this industry. The expansion of Juno Therapeutics' manufacturing presence in Washington state will increase Juno's ability to provide their potentially lifesaving treatments to more patients across the country and will produce high wage jobs in the region."

Juno will continue to work with its existing contract manufacturing partners to augment its manufacturing capabilities. Among other advantages, this will enhance flexibility, provide redundancy, and increase capacity in a cost effective manner.

About Juno

Juno Therapeutics, Inc. is building a fully integrated biopharmaceutical company focused on revolutionizing medicine by re-engaging the body's immune system to treat cancer. Founded on the vision that the use of human cells as therapeutic entities will drive one of the next important phases in medicine, Juno is developing cell-based cancer immunotherapies based on chimeric antigen receptor and high-affinity T cell receptor technologies to genetically engineer T cells to recognize and kill cancer. Juno is developing multiple cell-based product candidates to treat a variety of B-cell malignancies as well as solid tumors. Several product candidates have shown compelling evidence of tumor shrinkage in the clinical trials in refractory leukemia and lymphoma conducted to date. Juno's long-term aim is to improve and leverage its cell-based platform to develop new product candidates that address a broader range of cancers and human diseases. Juno brings together innovative technologies from some of the world's leading research institutions, including the Fred Hutchinson Cancer Research Center, Memorial Sloan Kettering Cancer Center, Seattle Children's Research Institute, and The National Cancer Institute.

www.JunoTherapeutics.com

Forward Looking Statements

This press release contains forward-looking statements, including statements regarding Juno's lease agreement for a facility located in Bothell, Washington, the activities and timing of events related to that facility, the success of Juno's development and commercialization efforts, the optimization of Juno's manufacturing capabilities, and patient outcomes. Forward-looking statements are subject to risks and uncertainties that could cause actual results to differ materially and reported results should not be considered as an indication of future performance. These risks and uncertainties include, but are not limited to: risks associated with the success, cost and timing of our product development activities and clinical trials; the approval and commercialization of our product candidates; and increased regulatory requirements; amongst others. For a further description of the risks and uncertainties that could cause actual results to differ from those expressed in these forward-looking statements, as well as risks relating to Juno's business in general, see Juno's Prospectus filed with the Securities and Exchange Commission on December 19, 2014. These forward-looking statements speak only as of the date hereof. Juno Therapeutics disclaims any obligation to update these forward-looking statements.