8-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): September 29, 2016

GENOCEA BIOSCIENCES, INC.

(Exact name of registrant as specified in its charter)

Delaware	001-36289	51-0596811
(State or other jurisdiction of incorporation)	(Commission File Number)	(IRS Employer Identification No.)

Cambridge Discovery Park 100 Acorn Park Drive, 5th Floor
Cambridge, MA	02140
(Address of principal executive offices)	(Zip Code)

(Registrant’s telephone number, including area code): (617) 876-8191

Not Applicable

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

oWritten communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

oSoliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

oPre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

oPre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Item 7.01. Regulation FD Disclosure.

On September 29, 2016, Genocea Biosciences, Inc. (the “Company”) issued a press release announcing positive viral shedding data from the Company’s planned interim analysis of data collected at the immediate post-dosing observation period in its ongoing Phase 2b trial evaluating a new Phase-3 ready formulation of GEN-003 for the treatment of genital herpes. A copy of the press release, dated September 29, 2016, is attached to this Current Report on Form 8-K as Exhibit 99.1 and is incorporated herein by reference.

On September 29, 2016, the Company will give a presentation to certain investors regarding the positive viral shedding data from the post-dosing analysis of the Company’s Phase 2b trial evaluating a new Phase-3 ready formulation of GEN-003 for the treatment of genital herpes.  A copy of the presentation is attached to this Current Report on Form 8-K as Exhibit 99.2 and is incorporated herein by reference.  The presentation is also available on the Company’s website, www.genocea.com, however the Company’s website and any information contained on the website are not incorporated herein.

The information contained in this Item 7.01 of this Current Report on Form 8-K, including the exhibits attached hereto, is being furnished and shall not be deemed “filed” for any purpose, and shall not be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Securities Exchange Act of 1934, as amended, regardless of any general incorporation language in any such filing.

Item 9.01 Financial Statements and Exhibits.

See Exhibit Index attached hereto.

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

	GENOCEA BIOSCIENCES, INC.
By:	/s/ Jonathan Poole
	Jonathan Poole Chief Financial Officer

Date: September 29, 2016

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EXHIBIT INDEX

Exhibit No.	Description
99.1	Press Release issued by Genocea Biosciences, Inc. on September 29, 2016
99.2	Investor Presentation dated September 29, 2016

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EX-99.1

Exhibit 99.1

Genocea’s Genital Herpes Immunotherapy GEN-003 Demonstrates Significant Reduction of Viral Shedding in Phase 2b Clinical Trial

- Trial achieves primary endpoint -

- Dose confirmed for subsequent trials -

- Phase 3 expected to start in 2H 2017 -

- Company to host conference call at 9 a.m. ET today -

CAMBRIDGE, Mass., September 29, 2016 --(GLOBE NEWSWIRE)-- Genocea Biosciences, Inc. (NASDAQ:GNCA), a biopharmaceutical company developing T cell-directed vaccines and immunotherapies, today announced positive results from its ongoing Phase 2b trial evaluating a new Phase 3-ready formulation of GEN-003 for the treatment of genital herpes. The study achieved its primary endpoint, with GEN-003 demonstrating a statistically significant reduction of 40 percent in the rate of viral shedding in the 60 µg per protein / 50 µg of Matrix-M2 dose group compared to both baseline and placebo. The viral shedding rate reduction for this dose was consistent with its performance at the same time point in a prior Phase 2 trial.

“We are very encouraged by this positive data and have now selected a dose of 60 µg per protein / 50 µg of Matrix-M2 of GEN-003 for our planned Phase 3 trials. This is the third consecutive trial in which GEN-003 has demonstrated a statistically significant reduction in viral activity immediately post-dosing. In the previous Phase 2 trial, success in this measure translated into a significant impact on genital herpes clinical disease, durable to at least 12 months,” said Chip Clark, president and chief executive officer of Genocea. “This body of data supports our strong belief that GEN-003 could be a cornerstone treatment for genital herpes. We look forward to reporting six-month placebo-controlled clinical data from this trial in January 2017 and expect to commence our Phase 3 program in the second half of 2017.”

During the 28-day observation period immediately after completion of dosing, the 60 µg per protein / 50 µg of Matrix-M2 dose of GEN-003 demonstrated a statistically significant 40 percent reduction from baseline in the viral shedding rate versus a marginal increase of 6 percent for placebo. The 60 µg per protein / 75 µg of Matrix-M2 dose demonstrated a 27 percent reduction in the viral shedding rate. The top-line viral shedding rate reductions for all of the dose groups in the trial are summarized in the following table:

	60 µg per protein / 50 µg of Matrix-M2	60 µg per protein / 75 µg of Matrix-M2	Placebo
Viral shedding rate reduction	-40%	-27%	+6%
p-value vs. baseline*	0.03	0.16	0.76
p-value vs. placebo*	0.05	0.20	NA

* Statistical analysis performed using a modified Poisson model (refined since Phase 2a trial with reference to advances in the field: Magaret, Amalia, "Models for HSV shedding must account for two levels of overdispersion" (January 2016). UW Biostatistics Working Paper Series. Working Paper 410. http://biostats.bepress.com/uwbiostat/paper410)

Safety in the trial was continuously reviewed by an independent Data Safety Monitoring Board. There was no grade 4 reactogenicity or related serious adverse events in this trial and discontinuations due to adverse events were low and similarly distributed across active dose groups and placebo.

“The established clinical profile of GEN-003 is one that could be highly beneficial to patients looking for an effective treatment which potentially offers greatly improved convenience over daily oral antivirals, the only current treatment option for the millions of people suffering from genital herpes,” said Lori A. Panther, M.D., MPH, Infectious Diseases specialist at Beth Israel Deaconess Medical Center and Assistant Professor of Medicine at Harvard Medical School. “I’m extremely encouraged by these results, once again demonstrating that GEN-003 reduces viral shedding. Control of viral shedding is fundamental to the control of genital herpes outbreaks and the epidemic spread of the disease.”

About the GEN-003 Phase 2b Clinical Trial

This Phase 2b trial is the first study testing potential Phase 3 endpoints with an improved formulation of GEN-003 - manufactured with commercially-scalable processes - which will be used in future Phase 3 trials. The trial enrolled 131 subjects from 9 institutions in the United States. Subjects have been randomized to one of three dose groups - placebo, 60 µg per protein / 50 µg of Matrix-M2 and 60 µg per protein / 75 µg of Matrix M2 - and have received three injections at 21-day intervals. Viral shedding rate reductions were measured to demonstrate the efficacy of the new formulation. The study will also compare GEN-003 efficacy to placebo for the clinical endpoints of: the proportion of patients who are lesion free at six and 12 months after dosing; the time to first lesion recurrence after dosing; and, the impact on percentage of days with genital herpes lesions at six and 12 months after dosing. All subjects will be followed for 12 months after the last dose.

For more information about this clinical study of GEN-003 please visit www.clinicaltrials.gov.

Conference Call

Genocea management will host a conference call and webcast today at 9 a.m. ET to review this data. The conference call may be accessed by dialing (844) 826-0619 for domestic participants and (315) 625-6883 for international callers (reference conference ID 87103963). A live webcast of the conference call will be available online from the investor relations section of the Company's website at http://ir.genocea.com. A webcast replay of the conference call will be available on the Genocea website beginning approximately two hours after the event, and will be archived for 30 days.

About GEN-003

Inducing a T cell response against genital herpes is critical to treating the clinical symptoms of disease and controlling transmission of the infection. GEN-003 is a first-in-class T cell directed immunotherapy designed to elicit both a T cell and B cell (antibody) immune response. The immunotherapy was designed using Genocea's ATLAS™ platform, which profiles the comprehensive spectrum of actual T cell responses mounted by humans in response to disease, to identify antigen targets that drive T cell response. GEN-003 includes the antigens ICP4 and gD2 along with Matrix-M2^TM adjuvant, which Genocea licenses from Novavax, Inc. For more information about GEN-003, please visit http://www.genocea.com/platform-pipeline/pipeline/gen003-for-genital-herpes/.

About Genital Herpes

Genital Herpes affects more than 400 million people worldwide and causes recurrent, painful genital lesions. It can be transmitted to sexual partners, even when the disease is asymptomatic. Current genital herpes therapies only partially control clinical symptoms and viral shedding, a process which drives disease transmission. Incomplete control of genital lesions and transmission risk, expense and the perceived inconvenience of taking a daily medication are hurdles for long-term disease management. Immunity through T cells is believed to be particularly critical to the control and possible prevention of genital herpes infections.

About Genocea

Genocea is harnessing the power of T cell immunity to develop life-changing vaccines and immunotherapies. T cells are increasingly recognized as a critical element of protective immune responses to a wide range of diseases, but traditional discovery methods have proven unable to identify the targets of such protective immune response. Using ATLAS, its proprietary technology platform, Genocea identifies these targets to potentially enable the rapid development of medicines to address critical patient needs. Genocea's pipeline of novel clinical stage T cell-enabled product candidates includes GEN-003 for genital herpes, GEN-004 for the prevention of infection by all serotypes of pneumococcus (development suspended pending further data analysis and consultation with our advisers), and earlier-stage programs in cancer immunotherapy, chlamydia, genital herpes prophylaxis and malaria. For more information, please visit the company's website at www.genocea.com.

Forward-Looking Statements

Statements herein relating to future business performance, conditions or strategies and other financial and business matters, including expectations regarding clinical developments, are forward-looking statements within the meaning of the Private Securities Litigation Reform Act. Genocea cautions that these forward-looking statements are subject to numerous assumptions, risks and uncertainties, which change over time. Factors that may cause actual results to differ materially from the results discussed in the forward-looking statements or historical experience include risks and uncertainties, including Genocea's ability to progress any product candidates in preclinical or clinical trials; the ability of ATLAS to identify promising oncology vaccine and immunotherapy product candidates; the scope, rate and progress of its preclinical studies and clinical trials and other research and development activities; anticipated clinical trial results; current results may not be predictive of future results; even if the data from preclinical studies or clinical trials is positive, regulatory authorities may require additional studies for approval and the product may not prove to be safe and efficacious; Genocea's ability to enter into future collaborations with industry partners and the government and the terms, timing and success of any such collaboration; risks associated with the manufacture and supply of clinical and

commercial product; the cost of filing, prosecuting, defending and enforcing any patent claims and other intellectual property rights; Genocea's ability to obtain rights to technology; competition for clinical resources and patient enrollment from drug candidates in development by other companies with greater resources and visibility; the rate of cash utilized by Genocea in its business and the period for which existing cash will be able to fund such operation; Genocea's ability to obtain adequate financing in the future through product licensing, co-promotional arrangements, public or private equity or debt financing or otherwise; general business conditions; competition; business abilities and judgment of personnel; the availability of qualified personnel and other factors set forth under "Risk Factors" in Genocea's Annual Report on Form 10-K for the fiscal year ended December 31, 2015 and other filings with the Securities and Exchange Commission (the "SEC"). Further information on the factors and risks that could affect Genocea's business, financial conditions and results of operations is contained in Genocea's filings with the SEC, which are available at www.sec.gov. These forward-looking statements speak only as of the date of this press release and Genocea assumes no duty to update forward-looking statements.

For media:         For investors:

Liz Bryan        Jonathan Poole

Spectrum Science Communications        Genocea Biosciences

O: 202-587-2526        O: 617-876-8191

lbryan@spectrumscience.comjonathan.poole@genocea.com

EX-99.2

Positive Viral Shedding Efficacy Results GEN-003 Immunotherapy for Genital Herpes Phase 2b Study September 29, 2016 Exhibit 99.2

This presentation contains “forward-looking” statements that are within the meaning of federal securities laws and are based on our management’s beliefs and assumptions and on information currently available to management. Forward-looking statements include information concerning our possible or assumed future results of operations, business strategies, financing plans, competitive position, industry environment, potential growth opportunities, potential market opportunities and the effects of competition. Forward-looking statements include all statements that are not historical facts and can be identified by terms such as “anticipates,” “believes,” “could,” “seeks,” “estimates,” “intends,” “may,” “plans,” “potential,” “predicts,” “projects,” “should,” “will,” “would” or similar expressions and the negatives of those terms. Forward- looking statements represent our management’s beliefs and assumptions only as of the date of this presentation. Our operations involve risks and uncertainties, many of which are outside our control, and any one of which, or combination of which, could materially affect our results of operations and whether the forward-looking statements ultimately prove to be correct. Factors that may materially affect our results of operations include, among other things, those listed in our Annual Report on Form 10-K and other filings with the Securities and Exchange Commission (“SEC”). Except as required by law, we assume no obligation to update these forward-looking statements publicly, or to update the reasons actual results could differ materially from those anticipated in the forward-looking statements, even if new information becomes available in the future. You may get copies of our Annual Report on Form 10-K, Quarterly Report on Form 10-Q and our other SEC filings for free by visiting EDGAR on the SEC website at http://www.sec.gov. 2 Safe Harbor Statement

• 60 µg per protein / 50 µg of Matrix-M2 adjuvant dose hit primary clinical trial endpoint – 40% viral shedding rate reduction consistent with prior trial • Safety profile acceptable – Low discontinuation rates due to AEs; distributed across dose groups, including placebo – No grade 4 reactogenicity or related AEs • GEN-003 on track for 2H 2017 Phase 3 start – Phase 2b 6 month clinical efficacy data expected: January 2017 – FDA end of Phase 2 meeting expected: Q1 2017 – Phase 2 antiviral combination study start expected: Q4 2016 3 Highlights

• Market potential for GEN-003 • Phase 2b trial – Study design – Top line data • Physician perspective – Lori A. Panther, MD, MPH • Important 2017 clinical and regulatory milestones • Conclusions • Q&A 4 Agenda for Today’s Call

• Genital herpes characterized by viral shedding, leading to disease transmission and genital lesions • Oral antiviral therapy insufficient for millions – Viral shedding reduced only when patients are taking medication but most use episodically – Lesions still occur even on chronic therapy • GEN-003 designed using ATLAS to direct T and B cells to fight clinical disease by reducing viral activity • GEN-003 product profile drives revenue opportunity of >$1bn in U.S. alone* 5 The Need for New Genital Herpes Treatments Drives Large Market Opportunity *Based on Genocea-sponsored market research

• Overall goal – Select dose of Phase 3-ready formulation of GEN-003 for Phase 3 trials • Primary endpoint – Compare efficacy versus baseline of two dose levels of GEN-003 and placebo by impact on viral shedding • Secondary objectives – Evaluate impact on clinical disease versus placebo at 6 and 12 months(a) • Proportion recurrence free • Time to next recurrence • Lesion rates – Safety and tolerability – Immunogenicity(a) 6 Phase 2b Trial Goals and Objectives (a) Not part of top-line read-out

• Randomized, double-blind, placebo-controlled • 131 subjects with a history of recurrent genital herpes • 3 dose groups, followed for 12 months – Placebo (n=44) – 60 µg per protein / 50 µg of Matrix-M2 (n=43) – 60 µg per protein / 75 µg of Matrix-M2 (n=44) • Consistent with prior trials – Inclusion / exclusion criteria, demographics, sites, dose regimen, endpoints, observation periods, swabbing compliance 7 Study Design

6% -40% -27% -50% -40% -30% -20% -10% 0% 10% Placebo 60/50 µg 60/75 µg R e d u c ti o n in V ira l S h e d d in g R a te v s. B a se lin e • In prior Phase 2, this antiviral efficacy increased to 66% at 12 months; led to significant and durable clinical efficacy at 6 & 12 months • 60 / 75 µg dose showed a 27% reduction vs. baseline (not significant) • Robust control arm in placebo group 8 Statistically Significant 40% Viral Shedding Rate Reduction for 60 / 50 µg Dose Viral Shedding Rate Reduction by Dose Group *Poisson model analysis (refined since prior Phase 2 trial with reference to advances in the field: Magaret, Amalia, "Models for HSV shedding must account for two levels of overdispersion" (January 2016). UW Biostatistics Working Paper Series. Working Paper 410. http://biostats.bepress.com/uwbiostat/paper410) p-values* vs. baseline 0.03 vs. placebo 0.05

• Safety continuously reviewed by Independent Data Safety Monitoring Board • Low discontinuation rate due to AEs; similarly distributed across dose groups including placebo • Reactogenicity consistent between 2 trials for 60 µg /50 µg dose • No grade 4 reactogenicity or related SAEs in either this trial or prior Phase 2 trial 9 Overall Summary of Safety

Lori A. Panther, MD, MPH Infectious Diseases specialist at Beth Israel Deaconess Medical Center and Assistant Professor of Medicine at Harvard Medical School GEN-003 Physician Perspective 10

11 Potential H2 2017 Phase 3 Start for GEN-003 On Track 2016 2017 6 month 6 month clinical 12 month FDA EoP2 Phase 2b Phase 2b Antiviral Combination Phase 3 Regulatory • Confirm robust efficacy with Phase 3 material • Confirm Phase 3 program • Explore potential additive effect

• Virologic efficacy profile of Phase 3-ready GEN-003 formulation confirmed for 60 / 50 µg dose ahead of Phase 3 • GEN-003 safety profile appears acceptable • 60 / 50 µg dose selected for subsequent trials – Phase 2b antiviral combination study start expected in Q4 – Potential Phase 3 start in second half of 2017 on track • 6 month Phase 2b clinical efficacy data expected January 2017 – In prior trial, virologic efficacy post dose 3 translated into significant and durable clinical efficacy, at 6 and 12 month time points 12 Conclusions

Questions & Answers 13

Liz Bryan Spectrum Science Communications Phone: +1 202-587-2526 lbryan@spectrumscience.com Investor inquiries: Media inquiries: Jonathan Poole Chief Financial Officer Phone: +1 617-876-8191 jonathan.poole@genocea.com