TAMPA, Florida, May 29, 2019 /PRNewswire/ -- GT Biopharma, Inc.
(OTCQB: GTBP) (OTC: GTBP.PA) an immuno-oncology company focused on
innovative treatments based on the Company's proprietary NK cell
engager (TriKE) platform and Multi-Target Directed Bispecific Drug
Conjugate (MTBDC) platform, announced today that the results of its
second Phase I-II trial (NCT02370160) for GTB-1550 (DT2219), an
MTBDC targeting CD22 and CD19 for treatment of refractory B-cell
malignancies, will be published (J Clin Oncology 37, 2019 suppl;
abstract e19066) on-line in conjunction with the 55th
Annual Meeting of the American Society of Clinical Oncology (ASCO)
in Chicago from May 31 – June
4.
Top Line Results Summary:
- Treatment was well tolerated at 60 mcg/kg x 8 doses and the
most common adverse events included capillary leak syndrome,
elevated AST/ALT, low albumin, weight gain and leukopenia.
All were Grade 1-2 and resolved after 3-5 days allowing day 15
GTB-1550 administration.
- There were no neutropenic fever or immune mediated adverse
events. Four patients experienced dose limiting toxicity
(DLT) at dose 80 μg/kg/day: Grade 4 capillary leak syndrome (n=1),
Grade 3 liver function test (LFT) abnormalities (n=2) and Grade 4
thrombocytopenia >7 days duration (n=1).
- Thirteen patients were evaluable for response, and 3
experienced objective clinical benefit. One patient with
primary refractory pre-B acute lymphoblastic leukemia achieved
complete remission after 1st cycle. Two patients with
transformed lymphoma demonstrated transient tumor shrinkage,
however, GTB-1550 therapy was discontinued due to DLT and increased
neutralizing antibody titer after 1st cycle (pre C1 28%, pre C2
108%).
- Correlative studies showed a low incidence of neutralizing
antibody in Non-Hodgkin Lymphoma (NHL) patients recently exposed to
Rituximab.
Mr. Anthony Cataldo, the Chairman
and Chief Executive Officer of GT Biopharma commented,
"We are pleased with the results
GTB-1550 has shown in the current Phase I-II clinical trial and in
our earlier Phase I-II clinical trial. This now positions us to
move forward with the FDA phase II clinical trial."
Dr. Veronika Bachanova, Associate Professor of Medicine,
Division of Hematology, Oncology and Transplantation at the
University of Minnesota and the
Principal Investigator for both clinical trials commented, "We are
excited about the progress GTB-1550 is making in the clinic, and
look forward to the possibility of exploring additional monotherapy
and synergistic combination studies against various B-cell
malignancies." Both clinical studies were conducted at the
University of Minnesota's Masonic
Cancer Center in Minneapolis.
About GTB-1550 Multi-Target Directed Bispecific
Therapy
GTB-1550 targets cancer cells expressing the CD19 receptor or
CD22 receptor or both receptors thereby maximizing cancer cell
recognition by binding to CD19+, CD22+ and CD19+/CD22+ cancer
cells. When GTB-1550 binds to cancer cells, the cancer cells
internalize GTB-1550, and are killed due to the action of drug's
cytotoxic diphtheria toxin payload. GTB-1550 has previously
demonstrated success in a Phase I-II human clinical trial in
patients with relapsed/refractory B-cell lymphoma or leukemia. At
the time of the interim review, 13 patients met the evaluation
criteria, including nine NHL and four ALL patients. More than
50% of patients (seven of 13) exhibited a clinical benefit, defined
as stable disease, partial remission or complete remission at Day
29. Of the seven patients, one demonstrated a complete
remission (CR), one demonstrated a partial remission (PR) and five
demonstrated stable disease (SD).
About the TriKE Platform
The Company's TriKE product candidates are single-chain,
tri-specific scFv recombinant fusion proteins composed of the
variable regions of the heavy and light chains (or heavy chain
only) of anti-CD16 antibodies, wild-type or a modified form of
IL-15 and the variable regions of the heavy and light chains of an
antibody designed to precisely target a specific tumor antigen. GT
Biopharma utilizes the NK stimulating cytokine human IL-15 as a
cross linker between the two scFvs which is designed to provide a
self-sustaining signal leading to the proliferation and activation
of NK cells thus enhancing their ability to kill cancer cells
mediated by antibody-dependent cell-mediated cytotoxicity
(ADCC). GT Biopharma has an exclusive worldwide license
agreement with the University of
Minnesota to further develop and commercialize cancer
therapies using proprietary TriKE technology developed by
researchers at the university to target NK cells to cancer.
About GT Biopharma, Inc.
GT Biopharma, Inc. is a clinical stage biopharmaceutical company
focused on the development and commercialization of immuno-oncology
products based off our proprietary Tri-specific Killer Engager
(TriKE) and Multi-Target Directed Bispecific Drug Conjugate (MTBDC)
technology platforms. Our TriKE platform is designed to harness and
enhance the cancer killing abilities of a patient's immune system
natural killer cells (NK cells). Our Multi-Target Directed
Bispecific Drug Conjugate (MTBDC) platform can generate product
candidates that are bi-specific, ligand-directed single-chain
fusion proteins that, we believe, represent the next generation of
targeted therapy.
Forward-Looking Statements
This press release contains certain forward-looking statements
that involve risks, uncertainties and assumptions that are
difficult to predict, including statements regarding the potential
acquisition, the likelihood of closing the potential transaction,
our clinical focus, and our current and proposed trials. Words and
expressions reflecting optimism, satisfaction or disappointment
with current prospects, as well as words such as "believes,"
"hopes," "intends," "estimates," "expects," "projects," "plans,"
"anticipates" and variations thereof, or the use of future tense,
identify forward-looking statements, but their absence does not
mean that a statement is not forward-looking. Our forward-looking
statements are not guarantees of performance and actual results
could differ materially from those contained in or expressed by
such statements. In evaluating all such statements, we urge you to
specifically consider the various risk factors identified in our
Form 10-K for the fiscal year ended December 31, 2018 in the
section titled "Risk Factors" in Part I, Item 1A and in our
subsequent filings with the Securities and Exchange Commission, any
of which could cause actual results to differ materially from those
indicated by our forward-looking statements.
Our forward-looking statements reflect our current views with
respect to future events and are based on currently available
financial, economic, scientific, and competitive data and
information on current business plans. You should not place undue
reliance on our forward-looking statements, which are subject to
risks and uncertainties relating to, among other things:
(i) the sufficiency of our cash position and our ongoing
ability to raise additional capital to fund our operations,
(ii) our ability to complete our contemplated clinical trials
for GTB-3550 or GTB-1550, or to meet the FDA's requirements with
respect to safety and efficacy, (iii) our ability to identify
patients to enroll in our clinical trials in a timely fashion,
(iv) our ability to achieve approval of a marketable product,
(v) design, implementation and conduct of clinical trials,
(vii) the results of our clinical trials, including the
possibility of unfavorable clinical trial results, (vii) the
market for, and marketability of, any product that is approved,
(viii) the existence or development of treatments that are
viewed by medical professionals or patients as superior to our
products, (ix) regulatory initiatives, compliance with
governmental regulations and the regulatory approval process, and
social conditions, and (x) various other matters, many of
which are beyond our control. Should one or more of these risks or
uncertainties develop, or should underlying assumptions prove to be
incorrect, actual results may vary materially and adversely from
those anticipated, believed, estimated, or otherwise indicated by
our forward-looking statements.
We intend that all forward-looking statements made in this press
release will be subject to the safe harbor protection of the
federal securities laws pursuant to Section 27A of the
Securities Act, to the extent applicable. Except as required by
law, we do not undertake any responsibility to update these
forward-looking statements to take into account events or
circumstances that occur after the date of this press
release. Additionally, we do not undertake any responsibility
to update you on the occurrence of any unanticipated events which
may cause actual results to differ from those expressed or implied
by these forward-looking statements.
For more information, please visit www.gtbiopharma.com.
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