Press Release

Eureka Therapeutics Announces Exclusive License Agreement Between Memorial Sloan Kettering Cancer Center And Juno Therapeutics For Use Of A Novel, Fully-Human MUC16 Binder In CAR T Cell Immunotherapy

EMERYVILLE, CA, Jan. 7th, 2016 – Eureka Therapeutics, Inc. announced today that Memorial Sloan Kettering Cancer Center and Juno Therapeutics, Inc. (Nasdaq: JUNO) have entered into an exclusive license agreement for a novel, fully-human binding domain targeting MUC16 to be used for the potential development and commercialization of chimeric antigen receptor (CAR) cell therapies for patients with MUC16 positive cancers, including ovarian, fallopian tube, and primary peritoneal cancers. The binder was developed under a collaboration agreement between Eureka Therapeutics and Memorial Sloan Kettering Cancer Center.

“We are excited that Juno Therapeutics, a leader in CAR and TCR technologies, will pursue the development of this binding domain as a CAR cell therapy,” said Dr. Cheng Liu, President and Chief Executive Officer of Eureka Therapeutics. “CAR cell therapy has shown promising potential for treating hematologic malignancies, and Eureka is working to accelerate the potential of the technology in a broader array of patients by developing antibodies that can recognize solid tumor antigens with the stringency required for CAR immunotherapy.”

“We are pleased to enter into this agreement, as we continue to pursue the development of fully-human binding domains, with the goal of optimizing cell persistence and potential patient benefit of our engineered cells,” said Mark Frohlich, M.D., Juno’s Executive Vice President, Development and Portfolio Strategy. “We opened a Phase I trial for our MUC16/IL-12 armored CAR product candidate in 2015, and if the safety and efficacy results are promising, this collaboration will allow us to more rapidly transition from the current murine binding domain to a fully-human binding domain.”

Under the terms of the exclusive license agreement, Memorial Sloan Kettering granted Juno Therapeutics an exclusive, worldwide license, under both Memorial Sloan Kettering’s and Eureka’s rights to certain MUC16 binding domains, to develop and commercialize the MUC16 binding domains as part of CAR cell therapies for all indications. In return, Memorial Sloan Kettering will receive an upfront payment and potential future payments upon achievement of certain development, regulatory, and sales milestones, and annual net sales royalty payments. Pursuant to the collaboration agreement between Eureka and Memorial Sloan Kettering, Eureka will receive a portion of these payments from Memorial Sloan Kettering. Juno will fund additional development and commercialization activities.

About Eureka Therapeutics, Inc.

Eureka Therapeutics, Inc. is a privately held biotechnology company, headquartered in the San Francisco Bay area, focused on developing first-in-class T cell immunotherapies for hematological malignancies and solid tumors. Its core technology platforms center around the discovery and engineering of fully human antibodies against intracellular targets via the MHCI complex. The company is developing a pipeline of novel cancer therapeutics targeting intracellular oncogenes.

Juno Therapeutics Forward-Looking Statements

This press release contains forward-looking statements, including statements regarding Juno’s business plans, the potential of T cell therapeutics, the potential of the MUC16 binding domain and other human binders, clinical trial results and clinical trial plans, and planned activities and potential payments under the collaboration between Juno and Memorial Sloan Kettering. Forward-looking statements are subject to risks and uncertainties that could cause actual results to differ materially from such forward-looking statements, 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 Juno’s product development activities and clinical trials; Juno’s ability to obtain regulatory approval for and to commercialize its product candidates; Juno’s ability to establish a commercially-viable manufacturing process and manufacturing infrastructure; regulatory requirements and regulatory developments; success of Juno’s competitors with respect to competing treatments and technologies; Juno’s dependence on third-party collaborators and other contractors in Juno’s research and development activities, including for the conduct of clinical trials and the manufacture of Juno’s product candidates; Juno’s dependence on Celgene for the development and commercialization outside of North America of product candidates for which Celgene exercises an option; Juno’s ability to obtain, maintain, or protect intellectual property rights related to its product candidates; 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 Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on November 12, 2015 and Juno’s other periodic reports filed with the Securities and Exchange Commission. These forward-looking statements speak only as of the date hereof. Juno disclaims any obligation to update these forward-looking statements.