- Galinpepimut-S (GPS) induced immune activation against Wilms tumor-1 (WT1) antigen as well as multifunctional
cross-epitope T-cell reactivity in patients with aggressive multiple myeloma
- Correlation noted between clinical and immune responses with promising progression free survival benefit
NEW YORK, March 19, 2018 (GLOBE NEWSWIRE) -- SELLAS Life Sciences Group, Inc. (NASDAQ:SLS) (“SELLAS” or “the Company”) today
announced the presentation of open label Phase 2 clinical and immunological data for its lead cancer immunotherapeutic candidate,
galinpepimut-S (GPS), in the treatment of high-risk multiple myeloma at the 44th Annual European Society for Blood and
Marrow Transplantation (EBMT) Meeting. Safety results from the study were also presented. The EBMT presentation is being delivered
by Guenther Koehne, M.D., Ph.D., Chief of Bone Marrow Transplantation and Hematologic Oncology at Miami Cancer Institute, Baptist
Health South Florida.
Median progression-free survival (PFS) of 23.6 months was reported in the high-risk disease setting, compared to historically
inferior outcomes while on an immunomodulatory drug (IMID) or proteasome inhibitor post-ASCT maintenance. Median overall
survival has not been reached to date. The open-label Phase 2 study consisted of 19 patients with multiple myeloma who had
high-risk cytogenetics at diagnosis and remained at least minimal residual disease (MRD)-positive after a successful autologous
stem cell transplant (“ASCT”).
“These results are encouraging particularly given the patients’ poor prognosis due to their high-risk cytogenetic profile at
disease presentation and their still harboring minimal residual disease prior to GPS treatment”, said Angelos M. Stergiou, M.D.,
Sc.D. h.c., President and CEO of Sellas. “The improved PFS at 23.6 months in this setting instills further confidence in our
advancing GPS development as an important immuno-therapeutic treatment option for aggressive multiple myeloma.”
GPS was administered to patients in the study who achieved a stable disease or better status following ASCT, but still exhibited at
least measurable minimal residual disease. GPS, a novel WT1-targeting direct immunizer, was evaluated as consolidation
therapy to potentially stimulate a highly-specific immune response against WT1 to prevent or delay myeloma progression.
In the study, key data findings were:
- Clinical activity was linked to antigen-specific immune responses.
- GPS stimulated time-dependent and robust CD4+ T cell or CD8+ T cell immune responses (IRs) specific for all four WT1 peptides
within GPS, two of which are heteroclitic (mutated, by design). In addition, GPS stimulated similar IRs against the two
counterpart native peptides. The IRs were confirmed in up to 91% of patients across HLA allele types, with multivalent IRs
emerging in up to 64% of patients.
- Multifunctional cross-epitope T cell reactivity was observed in 75% of patients to antigenic epitopes against which hosts
were not specifically immunized, in a pattern akin to epitope spreading.
- The GPS data suggest a distinctive link between clinical and immune responses, which has not been previously described for a
peptide vaccine in multiple myeloma. The results offer mechanistic underpinnings for immune activation against WT1 in patients
with aggressive multiple myeloma and are supportive of further testing of the putative anti-myeloma activity of GPS in more
extensive clinical studies.
Dr. Koehne’s complete EBMT presentation covering the GPS results can be accessed at: www.sellaslifesciences.com/publications/galinpepimut-s-gps/default.aspx.
“High-risk multiple myeloma is a disease subset with high potential of short-term disease progression following autologous stem
cell transplants, providing opportunities to improve on this limited clinical outcome. We are seeing an encouraging signal from GPS
in our Phase 2 study with progression-free survival (PFS) exceeding historical outcomes with standard therapies,” stated Guenther
Koehne, M.D., Ph.D. Dr. Koehne added that “Currently, post-transplant maintenance therapies for these difficult-to-treat
patients are seemingly limited, with PFS rarely exceeding 12-14 months”. Dr. Koehne was the Principal Investigator for this study
while at MSKCC.
About galinpepimut-S (GPS):
GPS is a heteroclitic multivalent, multi-peptide cancer immunotherapeutic agent composed of four peptides, addressing over 20
epitopes, and derived from the WT1 protein, which has been ranked by the National Cancer Institute as a top priority among cancer
antigens for immunotherapy. Importantly, because the WT1 antigen is overexpressed in many malignancies, and is not found in
most normal tissues, GPS has the potential to be a broad immunotherapy, effective across a multitude of diverse cancer types and
patient populations.
About SELLAS Life Sciences Group:
SELLAS is a clinical-stage biopharmaceutical company focused on novel cancer immunotherapeutics for a broad range of cancer
indications. SELLAS’ lead product candidate, galinpepimut-S (GPS), is licensed from Memorial Sloan Kettering Cancer Center and
targets the Wilms Tumor 1 (WT1) protein, which is present in an array of tumor types. SELLAS has Phase 3 clinical trials planned
(pending funding availability) for GPS in two indications, acute myeloid leukemia (AML) and malignant pleural mesothelioma (MPM),
and is also developing GPS as a potential treatment for multiple myeloma and ovarian cancer. SELLAS plans to study GPS in up
to four additional indications. SELLAS has received Orphan Drug designations from the U.S. Food & Drug Administration (FDA),
as well as the European Medicines Agency, for GPS in AML and MPM; GPS also received Fast Track designation for AML and MPM from the
FDA.
For more information on SELLAS, please visit www.sellaslifesciences.com.
Forward-Looking Statements
This press release contains forward-looking statements, including, but not limited to, statements related to the results of
clinical studies and as to further development of GPS for multiple myeloma as well as for a broad range of cancer indications.
These forward-looking statements are based on current plans, objectives, estimates, expectations and intentions, and inherently
involve significant risks and uncertainties. Actual results and the timing of events could differ materially from those anticipated
in such forward-looking statements as a result of these risks and uncertainties, which include, without limitation, risks and
uncertainties associated with immune-oncology product development and clinical success thereof, uncertainties related to timing and
ability to obtain needed shareholder consent in a timely manner, the uncertainty of regulatory approval, the uncertainty of
partnering its clinical assets, and other risks and uncertainties affecting SELLAS and its development programs. Other risks and
uncertainties of which SELLAS is not currently aware may also affect SELLAS’ forward-looking statements and may cause actual
results and the timing of events to differ materially from those anticipated. The forward-looking statements herein are made only
as of the date hereof. SELLAS undertakes no obligation to update or supplement any forward-looking statements to reflect actual
results, new information, future events, changes in its expectations or other circumstances that exist after the date as of which
the forward-looking statements were made.
Investor Contact:
Will O’Connor
Stern Investor Relations, Inc.
212-362-1200
ir@sellaslife.com
David Moser, JD
Sellas Life Sciences Group
813-864-2571
info@sellaslife.com
Source: SELLAS Life Sciences Group, Inc.
