SAN DIEGO, Aug. 15, 2016 /PRNewswire/ -- OncoSec Medical
Incorporated ("OncoSec") (NASDAQ: ONCS), a company developing
DNA-based intratumoral cancer immunotherapies, today announced the
publication of research showing that partially exhausted CD8+ cells
infiltrating melanoma tumors accurately predicted most patients'
responses to anti-PD-1 therapies. The findings, published in the
Journal of Clinical Investigation, show that the response to
pembrolizumab strongly correlated to the percent of CD8+
tumor-infiltrating lymphocytes (TILs) that expressed high levels of
both PD-1 and CTLA-4. The study was led by University of California, San Francisco (UCSF)
researchers and physicians. This exhaustion marker is currently
being used to select patients for the ongoing Phase II
investigator-sponsored clinical trial evaluating the combination of
OncoSec's investigational therapy, ImmunoPulse® IL-12,
and the approved anti-PD-1 therapy, pembrolizumab, in patients with
unresectable metastatic melanoma.
With tumor samples from a discovery cohort of 20 patients who
had received anti-PD-1 therapy, researchers used multiparameter
flow cytometry to sort cells according to immune biomarker
expression in the study. Researchers examined CD8+ cells to see
whether they expressed PD-1, CTLA-4, and other proteins. The number
of partially exhausted CD8+ cells in tumors that expressed high
levels of both PD-1 and CTLA-4 was a reliable biomarker of response
to anti-PD-1 therapy, with response defined by standard RECISTv1.1
criteria. This observation was confirmed in a separate validation
cohort of 20 patients.
"This paper supports the concept that the 'target cell' of
anti-PD-1 monoclonal antibodies (mAb) is the partially exhausted
CD8+ T-cell within the tumor, which can be readily quantified using
flow cytometry," said Robert H.
Pierce, MD, OncoSec Chief Scientific Strategist and
co-author of the paper. "We've taken advantage of this assay's
ability to strongly predict patients, who are unlikely to respond
to anti-PD-1 mAb monotherapy, and select these patients in our
ongoing Phase II trial, where we are combining intratumoral
electroporation of plasmid IL-12 and pembrolizumab."
"These findings represent an advance in the field of cancer
immunotherapy," said Adil Daud, MD,
director of Melanoma Clinical Research at the UCSF Helen Diller
Family Comprehensive Cancer Center. "Many tests examining PD-L1
levels in tumor tissue can only modestly discriminate between
responders and non-responders. This analysis accurately predicts
response to anti-PD-1 therapy and can be utilized in the clinic to
appropriately select patients with a high likelihood of achieving a
clinical response to PD-1 pathway inhibition."
OncoSec is assessing the anti-tumor activity, safety, and
tolerability of the combination of ImmunoPulse® IL-12
and pembrolizumab in melanoma patients in a Phase II clinical trial
sponsored by UCSF. This multi-center, open-label, single-arm trial
is the first study to use UCSF's T-cell exhaustion marker assay.
The study will test the hypothesis as to whether the addition of
ImmunoPulse® IL-12 to pembrolizumab can increase the
response rate in melanoma patients, who have a low likelihood of
responding to monotherapy with anti-PD-1 blockade. The key
endpoints of the study include: best overall response rate (BORR)
by RECIST v1.1 and immune-related Response Criteria (irRC); safety
and tolerability; duration of response; 24-week landmark
progression-free survival; median progression-free survival; and
overall survival. OncoSec expects to present data from this trial
in the second half of 2016.
About OncoSec Medical Incorporated
OncoSec is a
biotechnology company developing DNA-based intratumoral
immunotherapies with an investigational technology,
ImmunoPulse®, for the treatment of cancer.
ImmunoPulse® is designed to enhance the local delivery
and uptake of DNA-based immune-targeting agents, such as IL-12. In
Phase I and II clinical trials, ImmunoPulse® IL-12 has
demonstrated a favorable safety profile and evidence of anti-tumor
activity in the treatment of various solid tumors and has shown the
potential to reach beyond the site of local treatment to initiate a
systemic immune response. ImmunoPulse® IL-12, OncoSec's
lead program, is currently in clinical development for several
indications, including metastatic melanoma and triple-negative
breast cancer. The program's current focus is on the significant
unmet medical need in patients with melanoma who are refractory or
non-responsive to anti-PD-1/PD-L1 therapies. In addition to
ImmunoPulse® IL-12, the Company is also identifying and
developing new immune-targeting agents for use with the
ImmunoPulse® platform. For more information, please
visit www.oncosec.com.
University of California
Disclaimer
The information stated above was prepared by
OncoSec Medical Incorporated and reflects solely the opinion of the
corporation. Nothing in this statement shall be construed to imply
any support or endorsement of OncoSec Medical Incorporated, or any
of its products, by The Regents of the University of California, its officers, agents and
employees.
Cautionary Note Regarding Forward-Looking
Statements
This press release contains "forward-looking
statements" within the meaning of the U.S. Private Securities
Litigation Reform Act of 1995. Forward-looking statements can be
identified by words such as "can," "predict," "likelihood," "will,"
"hypothesis," "expect," "potential," "designed," "may," "could,"
and similar references to future periods.
Forward-looking statements are neither historical facts nor
assurances of future performance. Instead, they are based on
management's current preliminary expectations and are subject to
risks and uncertainties, which may cause our results to differ
materially and adversely from the statements contained herein.
Potential risks and uncertainties that could cause actual results
to differ from those predicted include, among others, the
following: uncertainties inherent in pre-clinical studies and
clinical trials, such as the ability to enroll patients in clinical
trials and the risk of adverse events; unexpected new data, safety
and technical issues; our ability to raise additional funding
necessary to fund continued operations; and the other factors
discussed in OncoSec's filings with the Securities and Exchange
Commission.
Undue reliance should not be placed on forward-looking
statements, which speak only as of the date they are made. OncoSec
disclaims any obligation to update any forward-looking statements
to reflect new information, events or circumstances after the date
they are made, or to reflect the occurrence of unanticipated
events.
Contact:
Mary
Marolla
OncoSec Medical Incorporated
855-662-6732
media@oncosec.com
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