(GALE) Phase 3 NeuVax™ Trial Achieves 70th Qualifying Disease Free Survival Event

Interim analysis results expected by the end of the second quarter

SAN RAMON, Calif., March 29, 2016  — Galena Biopharma, Inc. (NASDAQ:GALE), a biopharmaceutical company committed to the development and commercialization of targeted oncology therapeutics that address major unmet medical needs, today announced that the 70^th qualifying disease free survival (DFS) event has been achieved in the NeuVax™ (nelipepimut-S) Phase 3, PRESENT (Prevention of Recurrence in Early-Stage, Node Positive Breast Cancer with Low to Intermediate HER2 Expression with NeuVax Treatment) clinical trial. NeuVax is a peptide immunotherapy vaccine currently being evaluated for the prevention of cancer recurrence and is Galena’s lead development agent in multiple ongoing and planned clinical trials.

Based on clinical and radiological data, seventy qualifying DFS events have been confirmed by the trial’s independent Endpoint Adjudication Committee (EAC), comprised of two oncologists and one radiologist with expertise in the conduct of clinical trials in breast cancer. In the ensuing months, Galena will compile and submit the clinical data to the trial’s Independent Data Monitoring Committee (IDMC) to perform the Interim Analysis. The Interim Analysis is a pre-specified futility and overall safety analysis to evaluate the likelihood of the study to achieve its primary objectives. Upon completion of this prospective analysis, the IDMC will provide a recommendation to the Company regarding further continuation of the trial.

“We are pleased that we have achieved this important milestone in the PRESENT trial and that the rate of recurrences are in line with the original assumptions that led to the study design,” stated Bijan Nejadnik, M.D., Executive Vice President and Chief Medical Officer. “Reaching the 70^th qualifying DFS event triggers the pre-planned Interim Analysis. We will now prepare the data package for the IDMC in order for the committee to evaluate the safety of NeuVax for all patients enrolled, perform a futility analysis, and provide its recommendation on continuing the trial.  We anticipate reaching this next milestone in the PRESENT trial at the end of the second quarter.”

Dr. Nejadnik continued, “The 70^th event also represents a significant maturation of the program and is a meaningful time point as it brings us halfway to the full number of 141 events required for the primary endpoint analysis in conjunction with three years minimum follow-up. I am grateful to our clinical team, our committee’s physician experts, and our trial sites, as they have been instrumental in achieving this milestone.  With this point of progress in the trial, we are assembling our internal teams responsible for drafting our Biologics License Application.”

For the PRESENT trial, a qualifying DFS event is defined as: a recurrence of the primary breast cancer, either locally in the breast, regionally in the lymph nodes, or distantly as metastatic disease; an occurrence of another cancer; or, death from any cause. All qualifying DFS events are confirmed by the EAC. The IDMC is comprised of two medical oncologists, one cardiologist, and one statistician and will perform the Interim Analysis.

About PRESENT

PRESENT (Prevention of Recurrence in Early-Stage, Node-Positive Breast Cancer with Low to Intermediate HER2 Expression with NeuVax Treatment) is an international, Phase 3 study to evaluate NeuVax plus granulocyte macrophage-colony stimulating factor (GM-CSF) versus placebo plus GM-CSF to prevent cancer recurrence.  The trial is being run under a Special Protocol Assessment (SPA) granted by the U.S. Food and Drug Administration (FDA). PRESENT is targeting patients who are node positive, HER2 IHC 1+/2+, and HLA A2+ and/or A3+.  The study is double blind, randomized 1:1, and is stratified by stage, type of surgery, hormone receptor status, and menopausal status. Galena enrolled a total of 758 patients who constitute the Intention to Treat (ITT) population, and the primary endpoint for the trial is disease free survival (DFS) upon reaching 141 events with 3 years minimum follow-up.  Additional information on the trial can be found here and at clinicaltrials.gov identifier: NCT01479244.

About NeuVax™ (nelipepimut-S)

NeuVax™ (nelipepimut-S) is a first-in-class, HER2-directed cancer immunotherapy under evaluation to prevent breast cancer recurrence after standard of care treatment in the adjuvant setting.  It is the immunodominant peptide derived from the extracellular domain of the HER2 protein, a well-established target for therapeutic intervention in breast carcinoma. The nelipepimut-S sequence stimulates specific CD8+ cytotoxic T lymphocytes (CTLs) following binding to specific HLA molecules on antigen presenting cells (APC). These activated specific CTLs recognize, neutralize and destroy, through cell lysis, HER2 expressing cancer cells, including occult cancer cells and micrometastatic foci. The nelipepimut-S immune response can also generate CTLs to other immunogenic peptides through inter- and intra-antigenic epitope spreading.

In addition to PRESENT, Galena also has two breast cancer studies ongoing with NeuVax in combination with trastuzumab (Herceptin®; Genentech/Roche): a Phase 2b trial in node positive and triple negative HER2 IHC 1+/2+ (clinicaltrials.gov identifier: NCT01570036); and, a Phase 2 trial in high risk, node positive or negative HER2 IHC 3+ patients (clinicaltrials.gov identifier: NCT02297698).  Phase 2 clinical trials with NeuVax are also planned in patients with ductal carcinoma in situ (DCIS), and in patients with gastric cancer.

About HER2 1+/2+ Breast Cancer

According to the National Cancer Institute, over 230,000 women in the U.S. are diagnosed with breast cancer annually. Of these women, only about 25% are HER2 positive (IHC 3+). NeuVax targets approximately 50%-60% of these women who are HER2 low to intermediate (IHC 1+/2+ or FISH < 2.0) and achieve remission with current standard of care, but have no available HER2-targeted adjuvant treatment options to maintain their disease-free status.

About Galena Biopharma

Galena Biopharma, Inc. is a biopharmaceutical company committed to the development and commercialization of targeted oncology therapeutics that address major unmet medical needs. Galena’s development portfolio is focused primarily on addressing the rapidly growing patient populations of cancer survivors by harnessing the power of the immune system to prevent cancer recurrence. The Company’s pipeline consists of multiple mid- to late-stage clinical assets, including novel cancer immunotherapy programs led by NeuVax™ (nelipepimut-S) and GALE-301.  NeuVax is currently in a pivotal, Phase 3 breast cancer clinical trial with several concurrent Phase 2 trials ongoing both as a single agent and in combination with other therapies. GALE-301 is in a Phase 2a clinical trial in ovarian and endometrial cancers and in a Phase 1b given sequentially with GALE-302.   For more information, visit www.galenabiopharma.com.

Forward-Looking Statements

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995.  Such statements include, but are not limited to, statements about the progress of the development of Galena’s product candidates, patient enrollment in our clinical trials, as well as other statements related to the progress and timing of our development activities including the Phase 3 trial for NeuVax, present or future licensing, collaborative or financing arrangements, expected outcomes with regulatory agencies, and projected market opportunities for product candidates or that otherwise relate to future periods. These forward-looking statements are subject to a number of risks, uncertainties and assumptions, including those identified under “Risk Factors” in Galena’s Annual Report on Form 10-K for the year ended December 31, 2015 and most recent Quarterly Reports on Form 10-Q filed with the SEC. Actual results may differ materially from those contemplated by these forward-looking statements. Galena does not undertake to update any of these forward-looking statements to reflect a change in its views or events or circumstances that occur after the date of this press release.

NeuVax is a trademark of Galena Biopharma, Inc.

Contact:

Remy Bernarda
SVP, Investor Relations & Corporate Communications
(925) 498-7709
ir@galenabiopharma.com