Genocea Doses First Patients and Completes Enrollment in Part A of Phase 1/2a Clinical Trial for Neoantigen Vaccine Candidate...

Genocea Biosciences, Inc. (NASDAQ: GNCA), a biopharmaceutical company developing personalized cancer immunotherapies, today announced the dosing of the first patients in its Phase 1/2a clinical trial testing the safety, immunogenicity, and clinical efficacy of its neoantigen cancer vaccine candidate GEN-009. Genocea also announced that enrollment of patients in the first part of the clinical trial has been completed.

“Dosing the first patients with our GEN-009 vaccine represents a significant milestone for Genocea,” said Tom Davis, M.D., the company’s Chief Medical Officer. “Importantly, our GEN-009 vaccines use our ATLAS™ platform for neoantigen identification. Unlike machine-based approaches that predict neoantigens and only evaluate the patient’s tumor, ATLAS also uses each patient’s own immune cells not only to identify true neoantigens that already trigger anti-tumor cytokine responses, but also to eliminate “inhibitory” antigens that are frequently selected for vaccine inclusion by such in silico approaches. I am grateful to the patients eager to participate in our trial, to our investigators, and to my colleagues here at Genocea for creating the first vaccine that is genuinely personalized to each individual’s T cells and their tumor mutations.”

Dr. Davis added: “With Part A of the trial now fully enrolled, we are in a better position to predict when we will have the first immunogenicity data from these patients. As a result, we are updating our guidance today and look forward to reporting top-line results from this part of the study late in the second quarter of this year or early in the third quarter."

This Phase 1/2a GEN-009 clinical trial consists of three parts. Part A is studying the safety and immunogenicity of GEN-009 as monotherapy in cancer patients with no evidence of disease, but at high risk of relapse. This part of the program has accrued nine patients previously treated for melanoma, non-small cell lung cancer, head and neck cancer, or urothelial carcinoma. Following proof of immunogenicity, Genocea expects to study GEN-009 in combination with checkpoint inhibitors in patients with advanced or metastatic solid tumors (Part B) and in patients who have progressed despite checkpoint inhibitor therapy (Part C).

About Genocea Biosciences, Inc.Genocea's mission is to help conquer cancer by designing and delivering targeted cancer vaccines and immunotherapies. While traditional immunotherapy discovery methods have largely used predictive methods to propose T cell targets, or antigens, Genocea has developed ATLAS™, its proprietary technology platform, to identify clinically relevant antigens of T cells based on actual human immune responses. Genocea is currently studying the safety, immunogenicity, and efficacy of its lead neoantigen cancer vaccine, GEN-009, in a Phase 1/2a clinical trial. For more information, please visit www.genocea.com.

Genocea Forward-Looking Statement This press release includes forward-looking statements, including statements relating to the expected clinical development of GEN-009, within the meaning of the Private Securities Litigation Reform Act. Such forward-looking statements are subject to risks and uncertainties that could cause actual results to differ materially from those expressed or implied in such statements. Genocea cautions that these forward-looking statements are subject to numerous assumptions, risks and uncertainties that change over time. Applicable risks and uncertainties include those identified under the heading "Risk Factors" included in Genocea's Annual Report on Form 10-K for the year ended December 31, 2017 and any subsequent SEC filings. These forward-looking statements speak only as of the date of this press release and Genocea assumes no duty to update forward-looking statements, except as may be required by law.

Contact: Jennifer LaVin [e-mail]