Presentation provides immunologic and booster data on GALE-301/GALE-302
SAN RAMON, Calif., Nov. 14, 2016 (GLOBE NEWSWIRE) — Galena Biopharma, Inc. (NASDAQ:GALE), a biopharmaceutical company committed to the development and commercialization of hematology and oncology therapeutics that address unmet medical needs, today announced that data from Galena’s GALE-301/GALE-302 clinical program was presented at the Society for Immunotherapy of Cancer Conference 2016 in National Harbor, Maryland. GALE-301 (E39) and GALE-302 (E39’ – variant of E39) 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. The Phase 1b is a single-center, randomized, single-blinded, three-arm study in patients with breast or ovarian cancer diagnosis who were treated with standard of care and showed no evidence of disease at enrollment. This trial augments the Phase 1/2a trial with single-agent GALE-301 in ovarian and endometrial cancers.
Previous trials have demonstrated that although boosting vaccinations help to maintain long-lasting immunity, attenuated peptides may be a better choice for boosting because over-stimulation with an immunogenic peptide may lead to cytotoxic T lymphocyte (CTL) exhaustion and death. This phenomenon is known as antigen-induced cell death. The presentation, entitled, “Phase Ib Trial of Two Folate Binding Protein (FBP) Peptide Booster Vaccines (E39 and E39′) in Breast and Ovarian Cancer Patients,” reported the peptide-specific immune response to E39 and E39′ after different combinations of vaccination and boosting.
Both E39 and E39′ are well tolerated with all related adverse events at grade 1 or grade 2. Though numbers were small, patients boosted with the attenuated peptide showed increased CTL response to boosting regardless of significant residual immunity (SRI) resulting from the primary vaccination series (PVS). While this data needs to be confirmed with a larger sample size, this is consistent with the theoretical advantage of boosting with an attenuated peptide, which is expected to induce less antigen-induced cell death of CTLs.
“This data set on our FBP-targeted agents GALE-301 and GALE-302 provides critical information to understand how different booster regimens may impact the outcome for patients,” said Bijan Nejadnik, M.D., Executive Vice President and Chief Medical Officer. “Cancers are different in their level of over-expression of FBP. High expressors, such as ovarian cancer, are more likely to develop tolerance and may need a higher dosage or more antigen stimulation with a stronger vaccine such as GALE-301 to overcome the tolerance and be effective. On the other hand, ninety percent of patients enrolled In this Phase 1/2a trial were breast cancer patients with lower FBP expression who have less tolerance and may benefit from a more attenuated antigen such as GALE-302, or alternatively from a lower dosage of the immunodominant antigen vaccine such as GALE-301. This will lead to the desired balance with maximum effect, while preventing CTL exhaustion and antigen induced CTL death. We expect the final data set from this trial to be presented next year.”
Ex-vivo immunologic recognition of E39 was assessed by clonal expansion of CTLs and in-vivo response by delayed-type hypersensitivity (DTH). Immunologic data was gathered at 1- and 6-months post-booster and was then analyzed. The 6-month post-PVS immunologic data was used to assess patients for SRI, defined as ≥2-fold increase from pre-PVS in E39-specific CD8+T-cells. Patients were sorted into two groups: those with SRI (SRI) and without (nSRI). Patients within each group were randomized to one booster of either E39’ or E39 resulting in four groups:
- SRI receiving E39 (SRI-E39)
- SRI receiving E39′ (SRI-E39′)
- nSRI receiving E39 (nSRI-E39)
- nSRI receiving E39′ (nSRI-E39′)
Sixteen patients were found to have SRI and 12 had nSRI; these patients were randomized to booster arms (SRI-E39:n=9; SRI-E39′:n=7; nSRI-E39:n=7; nSRI-E39′:n=5). There were no clinicopathologic differences between groups. When comparing DTH pre-booster and at 1- and 6- months post-booster there were no significant differences between SRI vs nSRI (p=0.350, p=0.276, p=0.133, respectively), E39 vs. E39′ (p=0.270, p=0.329, p=0.228), nor between all four groups (p=0.394, p=0.555, p=0.191). Comparing the change in CTL’s from pre- and 6-months post-booster, regardless of SRI, patients boosted with E39’ had increased CTL (+0.02) while those boosted with E39 had decreased CTL (-0.07, p=0.077). There was no difference comparing the change in DTH between groups (p=0.927).
HLA-A2-positive breast or ovarian cancer patients were enrolled after completion of standard of care and without evidence of disease, regardless of FBP expression level. The PVS includes six inoculations, one every 3-4 weeks containing 250mcg GM-CSF plus 500mcg peptide in the first five patients per arm (n=14) and 250mcg GM-CSF + 1000mcg of peptide in the second five patients (n=16). Thirty-nine patients were randomized into three arms with 30 breast (n=27) or ovarian (n=3) cancer patients completing the PVS and assessed for this presentation:
- E39 (GALE-301) x 6 inoculations (n=10)
- E39 (GALE-301) x 3 inoculations followed by E39’ (GALE-302) x 3 inoculations (n=10)
- E39’ (GALE-302) x 3 inoculations followed by E39 (GALE-301) x 3 inoculations (n=10)
The poster presentation from the conference will be available on Galena’s website here.
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 CTLs to recognize and destroy FBP-expressing cancer cells. Two trials are ongoing with FBP peptides: 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 Breast Cancer1
New cases of breast cancer occur at an annual rate of 125 per 100,000 women in the U.S., with an estimated 246,660 new cases and 40,450 deaths in 2016. Approximately 89.7% of breast cancer patients are expected to survive five years after diagnosis. Approximately 12.4% of women will be diagnosed with breast cancer at some point during their lifetime (2011 – 2013 data). The prevalence data from 2013 showed an estimated 3,053,450 women living with breast cancer in the United States.
About Ovarian Cancer1
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.
1National 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 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 novel cancer immunotherapy programs including NeuVax™ (nelipepimut-S) and GALE-301/GALE-302. For more information, visit www.galenabiopharma.com.
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, including GALE-301 and GALE-302, patient enrollment in our clinical trials, as well as other statements related to the progress and timing of our development activities, 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.
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