Juno Therapeutics' CAR T Cell Product Candidate JCAR017 Continues to Demonstrate Encouraging Outcomes in Pediatric Patients With Relapsed/Refractory CD19 Positive Acute Lymphoblastic Leukemia

SEATTLE, April 21, 2015 (GLOBE NEWSWIRE) -- Juno Therapeutics, Inc. (Nasdaq:JUNO), a biopharmaceutical company focused on re-engaging the body's immune system to revolutionize the treatment of cancer, announced today encouraging clinical responses in a Phase 1 study evaluating JCAR017 in pediatric patients with relapsed/refractory acute lymphoblastic leukemia (ALL). The results of this trial to date demonstrated that 91% of patients achieved a complete remission as documented by flow cytometry. Adverse events were consistent with what has been previously reported. JCAR017 is a chimeric antigen receptor (CAR) T cell product candidate subject to a licensing arrangement with Seattle Children's Research Institute. The results were presented in an oral presentation at the American Association for Cancer Research (AACR) Annual Meeting 2015 in Philadelphia, Pennsylvania.

"The 91% remission rate in this Phase 1 study of JCAR017 is highly encouraging, particularly when considering these pediatric patients failed to respond to standard treatments," said Michael Jensen, M.D., Scientific Co-Founder, Juno Therapeutics, and Director of the Ben Towne Center for Childhood Cancer Research, Seattle Children's Research Institute. "Based on these results we are eager to advance this study, and to continue advancing the use of cell therapies to change how we treat cancer and provide patients the opportunity for better treatment options."

Data from the ongoing, open-label, Phase 1 dose escalation study were presented by Dr. Jensen at AACR today. The study is evaluating escalating doses of JCAR017 in pediatric patients with relapsed/refractory CD19 positive ALL. JCAR017, a defined cell product candidate, was successfully manufactured for all enrolled patients. The study was designed and conducted by Seattle Children's Research Institute with patients from Seattle Children's Research Institute.

In an intent-to-treat analysis, a complete remission documented by flow cytometry in 20 of 22 patients (91%) was measured. The complete remissions were observed at all doses evaluated in patients with prior CD19-directed therapy as well as in patients with infantile ALL. Severe cytokine release syndrome and/or severe neurotoxicity was observed in 8 patients. Four relapses have been observed to date, only one of which had CD19 positive disease.

"These data provide valuable translational insights into the biology of our therapies, furthering our mission of developing innovative cellular therapeutic treatments to re-direct the immune system to fight cancer," said Hans Bishop, chief executive officer of Juno Therapeutics. "Given the impressive clinical results with this defined cell product candidate, we are encouraged to begin testing of JCAR017 in adult patients with B cell malignancies, including non-Hodgkin lymphoma, later this year."

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.

Forward Looking Statements

This press release contains forward-looking statements, including statements regarding the continuation of the study at Seattle Children's Research Institute, the advancement of cell therapies, the provision of better treatment options, Juno's mission, and future testing supported by Juno. 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, and Juno's ability to finance these activities and 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 research institution 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 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 Prospectus filed with the Securities and Exchange Commission on December 19, 2014 and Juno's 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.

CONTACT: Investor Relations Contact: David Walsey, W2O Group dwalsey@w2ogroup.com, 858-617-0772 Media Contact: Andreas Marathovouniotis, W2O Group amarathis@w2ogroup.com, 212-301-7174

Source:Juno Therapeutics