Galena Biopharma Presents Positive Final GALE-301 (E39) Phase 1/2a Clinical Trial Data

SAN RAMON, Calif., March 17, 2017 (GLOBE NEWSWIRE) — Galena Biopharma, Inc. (NASDAQ:GALE), a biopharmaceutical company developing hematology and oncology therapeutics that address unmet medical needs, today announced the final analysis from the Company’s GALE-301 (E39) investigator-sponsored Phase 1/2a clinical trial.  The data was given during an oral presentation by Dr. Larry Maxwell at the Annual Meeting on Women’s Cancer 2017 hosted by the Society of Gynecologic Oncology. The presentation was entitled, “Analysis of a Phase I/IIa Trial Assessing E39+GM-CSF, a Folate Binding Protein Vaccine, to Prevent Recurrence in Ovarian and Endometrial Cancer Patients.” GALE-301 is a cancer immunotherapy consisting of a peptide derived from Folate Binding Protein (FBP) combined with the immune adjuvant, granulocyte macrophage-colony stimulating factor (GM-CSF) for the prevention of cancer recurrence in ovarian and endometrial cancer patients in the adjuvant setting. 

“This final data from our early stage clinical trial demonstrates that GALE-301 is well tolerated and we were able to obtain statistically significant disease free survival in a small number of patients treated with the optimal dose,” said Bijan Nejadnik, M.D., Executive Vice President and Chief Medical Officer. “The data also showed a meaningful correlation between delayed type hypersensitivity reactions and clinical outcomes indicating that the vaccine is able to generate an immune response.  The results of the trial also reiterate our focus on treating patients with primary disease after their initial standard of care treatment where we believe GALE-301 may provide the most benefit. On behalf of the entire Galena team, we would like to thank Dr. Maxwell and Dr. George Peoples whose work on our immunotherapy vaccines targeting FBP have set the stage for potential future trials to prevent ovarian cancer recurrence.”

The trial began as a dose-escalation Phase 1 trial, transitioning to a Phase 2a comparing expanded dose cohorts with a total of 51 patients enrolled, n=29 in the HLA-A2 positive vaccine group (VG) and n=22 in the HLA-A2 negative control group (CG).  Forty patients were enrolled after standard of care treatment of primary disease and 11 patients after treatment of recurrent disease (5 in the VG, 6 in the CG). All patients were disease-free at enrollment.  Following administration of vaccine, local and systemic toxicities were mild at the completion of the series with no grade 4 or 5 toxicities, and only 1 patient experienced grade 3 toxicity, with the most common local toxicities being induration at the injection site, erythema, and pruritus.   Systemic toxicities for the 1000mcg group did not show any significant difference as compared to the <1000mcg group.  The most common systemic toxicities were muscle pain, headache, and fatigue.

The final endpoint for the trial was disease free survival (DFS) after two years, or 24 months. The overall DFS for the VG (n=29) was 50% versus 44% for the CG (n=22)(p=0.594).  Importantly, the two-year DFS was significantly higher in the optimally dosed 1000mcg group  (n=15) with 77% DFS versus 44% DFS in the CG (n=22) patients (p=0.05). Patients with primary disease who received the 1000mcg dose appear to maintain a statistically significant benefit while those with recurrent disease were not. Given the small number of patients in the recurrence group, this finding needs to be confirmed in a larger trial. In the trial, those patients with a lower expression of FBP performed better with an 86% DFS in the VG (n=8) versus 18% in the CG (n=11), p=0.01.  This reiterated our prior analysis that high levels of FBP expression associated with more aggressive disease may outpace the immune response and diminish the therapeutic effects of the vaccine. The correlation between delayed type hypersensitivity (DTH) reactions and clinical outcome was also analyzed. DTH was significantly increased from pre- to post-vaccination in the group receiving the optimal dose of 1000 mcg (p=0.03).

The trial was conducted as a prospective Phase 1/2a trial of E39+GM-CSF to prevent recurrence in disease-free ovarian and endometrial cancer patients at high risk for recurrence after standard of care treatments. Eligible patients included patients with primary or recurrent endometrial, ovarian, fallopian tube, or peritoneal cancer.  Once enrolled, HLA-A2 positive patients were inoculated with E39+GM-CSF and HLA-A2 negative patients were followed prospectively as matched controls. The primary vaccination series consisted of six total vaccinations, one given every 21-28 days, and the dose escalation scheme consisted of dosing cohorts of 3 patients each receiving one of the following doses: 100μg, 500μg, and 1000μg in addition to 250μg GM-CSF.  Two booster inoculations were given, one every six months.  In vivo immune monitoring was assessed using DTH measured pre- and post-vaccination. Patients were monitored for evidence of clinical recurrence every 3 months and the pre-specified intention-to-treat analysis was performed at 12 and 24 months after the last patient was enrolled.

About GALE-301

GALE-301 is a cancer immunotherapy that consists of a peptide derived from Folate Binding Protein (FBP) combined with the immune adjuvant, granulocyte macrophage-colony stimulating factor (GM-CSF) for the prevention of cancer recurrence in the adjuvant setting.  FBP is a well-validated therapeutic target that is highly over-expressed in ovarian, endometrial and breast cancers. FBP is the source of immunogenic peptides that can stimulate cytotoxic T lymphocytes (CTLs) to recognize and destroy FBP-expressing cancer cells. Enrollment has been completed in the GALE-301 Phase 2a portion of the Phase 1/2a clinical trial in ovarian and endometrial cancer.

About Ovarian/Endometrial Cancers1

New cases of ovarian cancer occur at an annual rate of 11.9 per 100,000 women in the U.S., with an estimated 22,280 new cases and 14,240 deaths in 2016. Approximately 46.2% of ovarian cancer patients are expected to survive five years after diagnosis. Approximately 1.3% of women will be diagnosed with ovarian cancer at some point during their lifetime (2011 – 2013 data).  The prevalence data from 2013 showed an estimated 195,767 women living with ovarian cancer in the United States.

Due to the lack of specific symptoms, the majority of ovarian cancer patients are diagnosed at later stages of the disease, with an estimated 75% of women presenting with advanced-stage (III or IV) disease. These patients have their tumors routinely surgically debulked to minimal residual disease, and then are treated with platinum- and/or taxane-based chemotherapy. While many patients respond to this treatment regimen and become clinically free-of-disease, the majority of these patients will relapse.  Depending upon their level of residual disease, the risk for recurrence after completion of primary therapy ranges from 60% to 85%.  Unfortunately for these women, once the disease recurs, treatment options are limited and the disease remains incurable.

New cases of endometrial cancer occur at an annual rate of 25.4 per 100,000 women in the U.S., with an estimated 60,050 new cases and 10,470 deaths in 2016. Approximately 81.7% of endometrial cancer patients are expected to survive five years after diagnosis. Approximately 2.8% of women will be diagnosed with endometrial cancer at some point during their lifetime (2010 – 2013 data).  The prevalence data from 2013 showed an estimated 635,437 women living with endometrial cancer in the United States.

1National Cancer Institute Surveillance, Epidemiology, and End Results Program

About Galena Biopharma

Galena Biopharma, Inc. is a biopharmaceutical company developing hematology and oncology therapeutics that address unmet medical needs. Galena’s pipeline consists of multiple mid-to-late-stage clinical assets led by its hematology asset, GALE-401, and its novel cancer immunotherapy programs including NeuVax™ (nelipepimut-S) and GALE-301/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 evaluation of strategic alternatives, the timetable for completing the evaluation of strategic alternatives, 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, Galena’s current and prospective financial condition, liquidity and access to capital, 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, 2016, most recent Quarterly Reports on Form 10-Q, current reports on Form 8-K, and the prospectus supplement 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.

Source: Galena Biopharma, Inc.

CONTACT: Contact:

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