SAN RAMON, CA, USA I April 19, 2016 I 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 data from the booster phase of the Company’s GALE-301/GALE-302 Phase 1/2a clinical trial was presented at the American Association for Cancer Research (AACR) Annual Meeting.

The poster, entitled, “Comparing an attenuated booster (E39’) vs. E39 booster to potentiate the clinical benefit of the folate binding protein (FBP)-derived vaccine (E39 + GM-CSF) in a phase I/IIa trial to prevent recurrence in endometrial (EC) and ovarian cancer (OC) patients,” was presented today by Dr. Doreen Jackson from the San Antonio Military Medical Center.  In the Phase 2a portion of the trial, patients were randomized to two different boosters: E39 (GALE-301), versus E39’ (GALE-302). The purpose of the study was to evaluate the immune responses and determine which booster, if either, would provide a sustained immune response and potentially longer disease free survival (DFS) rates. 

The use of the wildtype peptide (GALE-301/E39) demonstrated the same tolerable safety profile as the attenuated peptide (GALE-302/E39’) with only Grade 1 local reactions and minimal Grade 2 toxicities.  Importantly, the percentage of patients who received two booster inoculations and remained disease free was significantly better in the drug treatment arm, versus the control arm (p=0.02), regardless of which booster was used. At median follow up of 16 months, the boosters demonstrated equivalent efficacy after two booster inoculations with an estimated, two-year DFS rate of 66.7% (GALE-301 n=7, GALE-302 n=7) in each booster arm versus 36% (n=22) in the control arm.

“In our GALE-301 Phase 2a trial, we randomized patients to determine an optimal boosting strategy and to see if there was an observable difference between boosting patients with GALE-301 versus the attenuated version of the peptide, GALE-302,” stated Bijan Nejadnik, M.D., Executive Vice President and Chief Medical Officer.  “The results show that both boosters were effective with no measurable difference between them, and we will consider this as we continue to evaluate the best path forward for our compounds targeting FBP.  The primary analysis of this trial will be presented at the upcoming American Society of Clinical Oncology meeting in June.” 

A total of 51 patients were enrolled in the Phase 1/2a trial with 29 HLA-A2-positive patients in the vaccine group (VG) and 22 HLA-A2-negative patients in the control group (CG).  Six monthly intradermal inoculations of GALE-301 plus 250mcg GM-CSF were administered to the VG to complete the primary vaccine series (PVS).  Patients were then randomized to receive two booster inoculations of 500mcg of GALE-301 or GALE-302 plus 250mcg GM-CSF at six and twelve months post-PVS.  Seventeen patients continued onto the booster series and were randomized with 14 receiving two boosters. There were no significant demographic or baseline differences between groups, no difference in toxicities were observed, and there were no Grade 3 or 4 toxicities in either group.

About GALE-301 and GALE-302

GALE-301 and GALE-302 are cancer immunotherapies that consist 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.  GALE-301 is the E39 peptide, while GALE-302 is an attenuated version of this peptide, known as E39’.  FBP is a well-validated therapeutic target that is highly over-expressed in ovarian, endometrial and breast cancers, and is the source of immunogenic peptides that can stimulate cytotoxic T lymphocytes (CTLs) to recognize and destroy FBP-expressing cancer cells. Two trials are ongoing with FBP peptides in gynecological cancers: the GALE-301 Phase 2a portion of the Phase 1/2a clinical trial is ongoing in ovarian and endometrial adenocarcinomas (ClinicalTrials.gov Identifier: NCT01580696); the GALE-301 plus GALE-302 Phase 1b clinical trial is ongoing in breast and ovarian cancers (ClinicalTrials.gov Identifier: NCT02019524).

About Ovarian/Endometrial Cancers

New cases of ovarian cancer occur at an annual rate of 12.1 per 100,000 women in the U.S., with an estimated 21,290 cases for 2015. Although ovarian cancer represents about 1.3% of all cancers, it represents about 2.4% of all cancer deaths, or an estimated 14,180 deaths in 2015.  Approximately 1.3% of women will be diagnosed with ovarian cancer at some point during their lifetime (2010 – 2012 data).  The prevalence of ovarian cancer in the U.S. is about 192,000 women, and the five-year survivorship for women with ovarian cancer is 45.6%. 

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 25.1 per 100,000 women in the U.S., with an estimated 54,870 cases for 2015. Although endometrial cancer represents about 3.3% of all cancers, it represents about 1.7% of all cancer deaths, or an estimated 10,170 deaths in 2015.  Approximately 2.8% of women will be diagnosed with endometrial cancer at some point during their lifetime (2010 – 2012 data).  The prevalence of endometrial cancer in the U.S. is about 620,000 women, and the five-year survivorship for women with endometrial cancer is 81.7%. 

Source: National Cancer Institute Surveillance, Epidemiology, and End Results Program

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.

SOURCE: Galena Biopharma