SAN FRANCISCO, July 20, 2019 /PRNewswire/ -- Marker
Therapeutics, Inc. (Nasdaq: MRKR), a clinical-stage
immuno-oncology company specializing in the development of
next-generation T cell-based immunotherapies for the treatment of
hematological malignancies and solid tumor indications, today
announced interim data from an ongoing investigator-sponsored
clinical trial led by Baylor College of
Medicine, evaluating the Company's MultiTAA T cell therapy
in patients with pancreatic adenocarcinoma. The data were reviewed
today in an oral presentation during a plenary session, as well as
a poster presentation, at the American Association for Cancer
Research's (AACR) Immune Cell Therapies for Cancer: Successes and
Challenges of CAR T Cells and Other Forms of Adoptive Therapy
conference held in San Francisco,
California from July 19-22, 2019.
"Pancreatic cancer continues to be one of the most challenging
solid tumor malignancies to treat and survival rates have not seen
a meaningful improvement in more than 40 years," said Brandon
G. Smaglo, M.D., FACP, lead investigator and Assistant Professor of
Oncology at Baylor College of Medicine. "We are encouraged by
these interim data which suggest that MultiTAA therapy may
contribute to more durable responses without added toxicity when
used in combination with standard-of-care chemotherapy, or as a
second-line therapy for patients who are chemo-refractory.
Additionally, despite the particularly dense desmoplastic stroma
surrounding pancreatic tumors—which has been long considered a
major obstacle for T cell effectiveness—our study of patients with
borderline surgically resectable disease suggests that MultiTAA
cells are capable of meaningfully infiltrating the tumor."
Trial Overview
Title: Targeting pancreatic cancer using non-engineered,
multi-antigen specific T cells (TACTOPS)
The trial plans to enroll a total of 45 patients with advanced
or borderline resectable pancreatic adenocarcinoma in a three-arm
trial. Arm A is for patients with unresectable/metastatic disease
who are responding to standard first-line chemotherapy. Arm B is
for patients with progressive disease or therapy intolerance. Arm C
is an exploratory arm for patients with surgically resectable
disease. To date, a total of 19 patients have been
administered infusions of MultiTAA T cell therapy (ten patients in
Arm A, six patients in Arm B and three patients in Arm C).
Interim Results
Arm A: This arm was designed to evaluate the safety and
potential efficacy of using MultiTAA cells as part of first-line
treatment for patients with pancreatic cancer. These patients in
the chemo-responsive arm have completed or will complete at least
three months of standard-of-care chemotherapy
(gemcitabine/nab-paclitaxel or FOLFIRINOX) – the period during
which a response to chemotherapy would typically occur – before
receiving up to six administrations of MultiTAA T cells in
conjunction with chemotherapy.
- Out of the 9 evaluable patients (one patient was too early to
be evaluated):
-
- 3 patients experienced objective responses after administration
of MultiTAA cells
-
- 1 patient experienced a complete response
- 2 patients experienced partial responses
- 4 patients experienced stable disease; 2 patients within stable
disease boundaries (+20%/-30%) saw reversal of tumor growth –
tumors previously growing after chemotherapy alone showed shrinkage
after administration of MultiTAA cells
- 1 patient experienced a mixed response (some lesions increased
in size and others decreased for a net zero change in size of tumor
lesions)
- 1 patient experienced disease progression
- Overall tumor volume shrinkage was observed in six out of the
eight patients with a measurable tumor after administration of
MultiTAA cells. One evaluable patient did not have tumor
measurements for analysis.
- Of the 9 evaluable patients, over half have survived to or
beyond the historical median overall survival associated with their
respective chemotherapy regimens, and 7 of the 9 patients remain
alive.
- In patients responding to therapy, significant expansion of the
infused MultiTAA cells was observed, along with broad-based epitope
spreading, with significant expansion of endogenous T cells
specific for other tumor specific antigens.
Arm B: This arm was designed to evaluate the use of
MultiTAA cells as a second-line therapy for patients who have
failed first-line chemotherapy. The patients in this
chemo-refractory arm are either ineligible for chemotherapy or have
progressed on chemotherapy and have received or are receiving up to
six doses of MultiTAA T cells as a monotherapy.
- Of the 6 patients treated and evaluable:
-
- 3 patients experienced stable disease or clinical disease
stabilization
-
- 2 patients who previously had progressive disease experienced
clinical disease stabilization for up to two months
- 1 has maintained stable disease for 7 months (ongoing)
- 3 experienced clinical decline
- Among the patients who saw clinical disease stabilization,
significant expansion of the infused MultiTAA cells was observed,
along with broad-based epitope spreading, with significant
expansion of endogenous T cells specific for other tumor specific
antigens.
Arm C: This arm was designed to assess T cell
infiltration and expansion. These patients with borderline
surgically resectable disease received or will receive a dose of T
cells following chemotherapy, radiotherapy or combination prior to
surgical resection and up to five additional doses of T cells after
surgery.
- In these patients, MultiTAA T cells were measurable in
meaningful numbers as detected by correlative analysis of resected
tumor, and significant expansion of the infused MultiTAA cells was
observed, along with broad-based epitope spreading, with
significant expansion of endogenous T cells specific for other
tumor specific antigens.
Overall, investigators observed a clinical benefit correlated
with the detection of tumor-reactive T cells in patient peripheral
blood (Arms A, B and C) and within tumor biopsy samples (Arm C)
post-infusion. T cells exhibited activity against both targeted
antigens as well as non-targeted TAAs including WT-1, AFP, MART-1
and numerous antigens of the MAGE family, indicating induction of
antigen/epitope spreading.
No infusion-related systemic- or neurotoxicity was observed, and
patients continue to be evaluated and enrolled in the trial.
Peter L. Hoang, President &
CEO of Marker Therapeutics commented: "We are encouraged by the
early clinical results we have seen in this clinical trial for
patients who otherwise have few therapeutic options and a dire
prognostic outcome, and we are optimistic about the prospect of
potentially validating the use of MultiTAA therapy in the context
of first-line and second-line care for patients with pancreatic
adenocarcinoma. Moreover, we are very pleased with the data we see
of MultiTAA T cell infiltration and subsequent epitope spreading
observed in this trial, suggesting that MultiTAA therapy may
initiate and contribute to a potent and durable treatment effect.
We plan to continue following these patients and enroll new
patients to further evaluate durability."
Conference Call and Webcast
For those
unable to attend the presentations at AACR, Marker will host a
conference call and webcast on Monday, July
22nd at 5:30am
PDT/8:30am EDT featuring Dr.
Brandon Smaglo, as well as Marker
senior management. A live webcast of the investor presentation will
be available in the investors section of the Company's
website at https://www.markertherapeutics.com/ and will
be available for replay following the event.
About MultiTAA
Marker's Multi-Antigen Targeted
(MultiTAA) platform is a novel, non-genetically modified cell
therapy approach that selectively expands tumor-specific T cells
from a patient's blood capable of recognizing a broad range of
tumor antigens. In early clinical trials, the multi-antigen
approach has been well tolerated and shown to enhance tumor
destroying capability and is one of the first therapies to
consistently demonstrate epitope spreading – inducing the patient's
own T cells to expand, potentially contributing to a lasting
anti-tumor effect. Unlike other cell therapies which require
pre-conditioning regimens and hospitalization, MultiTAA is designed
to be administered in an outpatient setting.
About Marker Therapeutics, Inc.
Marker
Therapeutics, Inc. is a clinical-stage immuno-oncology company
specializing in the development of next-generation T cell-based
immunotherapies for the treatment of hematological malignancies and
solid tumor indications. Marker's cell therapy technology is based
on the selective expansion of non-engineered, tumor-specific T
cells that recognize tumor associated antigens (i.e. tumor targets)
and kill tumor cells expressing those targets. This population of T
cells is designed to attack multiple tumor targets following
infusion into patients and to activate the patient's immune system
to produce broad spectrum anti-tumor activity. Because Marker does
not genetically engineer its T cells therapies, we believe that our
product candidates will be easier and less expensive to
manufacture, with reduced toxicities, compared to current
engineered CAR-T and TCR-based approaches, and may provide patients
with meaningful clinical benefit. As a result, Marker believes its
portfolio of T cell therapies has a compelling product profile, as
compared to current gene-modified CAR-T and TCR-based
therapies.
Marker is also advancing a number of innovative peptide- and
gene-based immuno-therapeutics for the treatment of metastatic
solid tumors, including the Folate Receptor Alpha program (TPIV200)
for breast and ovarian cancers and the HER2/neu program
(TPIV100/110) for breast cancer, currently in Phase 2 clinical
trials.
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Forward-Looking Statement Disclaimer
This release
contains forward-looking statements for purposes of the safe harbor
provisions of the Private Securities Litigation Reform Act of 1995.
Statements in this news release concerning the Company's
expectations, plans, business outlook or future performance, and
any other statements concerning assumptions made or expectations as
to any future events, conditions, performance or other matters, are
"forward-looking statements." Forward-looking statements include
statements regarding our intentions, beliefs, projections, outlook,
analyses or current expectations concerning, among other things:
the final trial results for MultiTAA T cell therapy in patients
with pancreatic adenocarcinoma; our research and development
activities relating to our non-engineered multi-tumor antigen
specific T cell therapies; our TPIV200 and TPIV100/110 programs;
the effectiveness of these programs or the possible range of
application and potential curative effects and safety in the
treatment of diseases; and, the timing and success of our clinical
trials, as well as clinical trials conducted by our collaborators.
Forward-looking statements are by their nature subject to risks,
uncertainties and other factors which could cause actual results to
differ materially from those stated in such statements. Such risks,
uncertainties and factors include, but are not limited to the risks
set forth in the Company's most recent Form 10-K, 10-Q and other
SEC filings which are available through EDGAR at www.sec.gov. The
Company assumes no obligation to update our forward-looking
statements whether as a result of new information, future events or
otherwise, after the date of this press release.
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SOURCE Marker Therapeutics, Inc.