Seven out of eight patients treated on Part A of the study are without disease progression at one-year median follow-up

ATLAS™-identified neoantigens generate broad, sustained T cell responses starting after only 4 weeks and lasting for up to 6 months after the last vaccination

CAMBRIDGE, Mass., May 13, 2020 (GLOBE NEWSWIRE) -- Genocea Biosciences, Inc. (NASDAQ: GNCA), a biopharmaceutical company developing next-generation neoantigen immunotherapies, will present updated durability, safety and immunogenicity clinical data from Part A of its ongoing Phase 1/2a trial for GEN-009, the company’s lead neoantigen vaccine candidate at the virtual 2020 American Society for Clinical Oncology (ASCO) Annual Meeting from May 29-31.

The analysis evaluates eight patients from Part A of the trial who were vaccinated with GEN-009 as adjuvant therapy, focusing on the onset and duration of induced immunity and clinical outcomes. Seven out of the eight patients enrolled have continued without progression with a median follow up of over one year. All patients received dosing as planned with five doses given over a six-month period. No significant adverse side effects were reported with the administration of GEN-009, with only mild symptoms associated with the vaccine adjuvant.

GEN-009 vaccination also generated immune responses across 99% of neoantigen targets while avoiding inhibitory peptides also known as Inhibigens™, or antigens that drive inhibitory T cell responses. Both CD8⁺ and CD4⁺ responses were measured in both ex vivo and in vitro assays, and were detected as early as day 29 extending as far out as 12 months.

“I am pleased to see early and durable immune responses and favorable patient outcomes in Part A of the GEN-009 trial,” said Roger Cohen, M.D., Associate Director of Clinical Research, Abramson Cancer Center. “While we can’t assess the specific contribution of the vaccine in the adjuvant setting in this mixed population, the progression-free survival, safety and immunogenicity results support the role that GEN-009 could play in the therapy of multiple tumor types.”

“We are very pleased to find that these patients have done so well with GEN-009 vaccination. The breadth and durability of immune response as well as the clinical outcomes strengthen our excitement to see the effects of combination therapy in patients with measurable tumors,” said Thomas Davis, M.D., Chief Medical Officer of Genocea. “We are eager to elaborate further on our latest GEN-009 findings at the upcoming ASCO meeting and look forward to sharing additional data from Part B of this study on the benefits of the vaccine in patients receiving immune checkpoint inhibitors later this year.”

ASCO POSTER SESSION: Developmental Therapeutics – Immunotherapy
Abstract 3107

Title: GEN-009, a neoantigen vaccine containing ATLAS selected neoantigens, to generate broad sustained immunity against immunogenic tumor mutations and avoid inhibitory peptides.

Presenter: Roger B. Cohen, M.D., University of Pennsylvania Abramson Cancer Center
Date: May 29, 2020
Time: 8:00 – 11:00 a.m. EDT

About Genocea Biosciences, Inc.
Genocea’s mission is to conquer cancer by developing personalized cancer immunotherapies in multiple tumor types.  Our unique ATLAS™ platform comprehensively profiles each patient’s T cell responses to potential targets, or antigens, on the tumor. ATLAS enables us to optimize the neoantigens for inclusion in our immunotherapies and exclude inhibitory antigens that can exert an immunosuppressive effect. We are advancing two ATLAS-enabled programs: GEN-009, our neoantigen vaccine for which we are conducting a Phase 1/2a clinical trial and expect preliminary clinical results in the third quarter of 2020, and GEN-011, our neoantigen-specific cell therapy using T cells derived from peripheral blood, for which we intend to file an Investigational New Drug Application in the second quarter of 2020. To learn more, please visit www.genocea.com.

Forward-Looking Statements
This press release includes forward-looking statements, including statements relating to GEN-009 and GEN-011, 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, 2019 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.

Investor Contact:
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