Safety Review Committee Reports Encouraging
Drug Distribution and Tolerability
TORONTO and HOUSTON, Sept. 28,
2017 /PRNewswire/ - Medicenna Therapeutics Corp.
("Medicenna" or the "Company") (TSX: MDNA), a
clinical stage immuno-oncology company, announced today that based
on encouraging drug distribution and safety data observed in the
on-going Phase 2b clinical trial of MDNA55 for the treatment of
patients with recurrent glioblastoma (rGBM), the Company has
commenced implementation of an updated protocol following its
submission to the U.S. Food and Drug Administration (FDA) and
approval by the respective Institutional Review Boards (IRBs). The
amended protocol incorporates an enhanced drug delivery procedure
which will be used for the treatment of the remaining patients. The
updated protocol includes higher doses and volumes of MDNA55 as
well as an increase in the total expected study size – from 43
patients under the original protocol to 52 total planned patients
now expected to enroll. Patient enrolment and treatment continues
at multiple sites.
"Based on data that will be presented at the 2017 CNS conference
in Boston (7-11 October 2017), we are pleased with the
encouraging drug distribution, safety and tolerability of MDNA55 in
our ongoing Phase 2b rGBM study," stated Dr. Fahar Merchant, Chairman, President and CEO of
Medicenna. "These data indicate a wider therapeutic window than
originally anticipated and we can leverage this new, preliminary
safety understanding for the remainder of the study. The decision
to amend the study protocol by increasing the dosage and volume of
MDNA55 has the potential to address the needs of an expanded
patient population, including patients with larger or multi-focal
tumors."
This protocol amendment was based on a planned safety analysis
following a unanimous recommendation from MDNA55's Safety Review
Committee (SRC) after enrollment of the first six patients. Based
on the exceptional safety profile, the concentration of MDNA55 will
be doubled to 3.0 mg/mL and the volume administered will be
maximized to a fixed volume of 60mL to ensure complete tumor
coverage along with the surrounding margin of the tumor,
irrespective of tumor size. The protocol amendment was discussed
with all current investigators and input was received from thought
leaders in the area of glioblastoma and Convection-Enhanced
Delivery (CED) in order to optimize patient benefit following a
single treatment with MDNA55. The maximum dose of 180mg is
well within the established safety profile based on earlier
studies.
"By increasing the infusion volume, we are seeking to ensure
optimal coverage of the tumor and the surrounding penumbra. Early
results from the interim safety analysis indicates that the current
dose of MDNA55 has been well tolerated in the initial cohort of
patients," said John H. Sampson, MD,
PhD, MBA, MHSc, Chair of the Department of Neurosurgery,
Duke University School of Medicine.
In the amendment of the protocol, the primary endpoint of the
study remains the same: To determine the objective response rate
(ORR) per a modified RANO (Response Assessment in Neuro-Oncology)
criteria following a single intra- and peri-tumoral infusion of
MDNA55 using CED.
A single-stage binomial design test for a null ORR of 6% versus
an alternative ("pursue") ORR of 18%, at alpha = 0.1, 1-sided, will
have 80% power with 36 evaluable subjects. The sample size of the
study has been increased from 43 to 52 patients including 35
patients under the amended protocol. The Company expects enrollment
to be completed by early 2018, with interim top-line results
expected during the first half of 2018.
Details regarding the protocol amendment for MDNA55-05 will be
available on ClinicalTrials.gov.
About Medicenna Therapeutics Corp.
Medicenna is a clinical stage immuno-oncology company developing
novel highly selective versions of IL-2, IL-4 and IL-13 Superkines™
and first in class Empowered Cytokines™ (ECs). Its wholly
owned subsidiary, Houston-based Medicenna BioPharma, is
specifically targeting the Interleukin-4 Receptor (IL4R), which is
over-expressed by at least 20 different types of cancer affecting
more than one million new cancer patients every year. Medicenna's
lead IL4-EC, MDNA55 is enrolling patients in a Phase 2b clinical
trial for rGB at leading brain cancer centres in the US. MDNA55 has
completed 3 clinical trials in 72 patients, including 66 adults
with rGB, demonstrated compelling efficacy and obtained Fast-Track
and Orphan Drug status from USFDA. Unlike most other cancer
therapies, Medicenna's IL4-ECs have the potential to purge both the
tumor and the immunosuppressive tumor microenvironment, offering a
unique treatment paradigm for a large majority of cancer
patients.
For more information, please visit www.medicenna.com.
This news release contains forward-looking statements
relating to the future operations of the Company and other
statements that are not historical facts. Forward-looking
statements are often identified by terms such as "will", "may",
"should", "anticipate", "expects" and similar expressions. All
statements other than statements of historical fact, included in
this release, including, without limitation, statements regarding
future plans and objectives of the Company, the that optimal tumor
coverage will be achieved with the protocol amendment described,
the ongoing status of the Phase 2b clinical trial of MDNA55 for the
treatment of recurrent glioblastoma and others are forward-looking
statements that involve risks and uncertainties. There can be no
assurance that such statements will prove to be accurate and actual
results and future events could differ materially from those
anticipated in such statements. Important factors that could cause
actual results to differ materially from the Company's expectations
include the risks detailed in the annual information form of the
Company dated June 15, 2017 and in
other filings made by the Company with the applicable securities
regulators from time to time.
The reader is cautioned that assumptions used in the
preparation of any forward-looking information may prove to be
incorrect. Events or circumstances may cause actual results to
differ materially from those predicted, as a result of numerous
known and unknown risks, uncertainties, and other factors, many of
which are beyond the control of the Company. The reader is
cautioned not to place undue reliance on any forward-looking
information. Such information, although considered reasonable by
management at the time of preparation, may prove to be incorrect
and actual results may differ materially from those anticipated.
Forward-looking statements contained in this news release are
expressly qualified by this cautionary statement. The
forward-looking statements contained in this news release are made
as of the date of this news release and the Company will update or
revise publicly any of the included forward-looking statements only
as expressly required by Canadian securities law.
SOURCE Medicenna Therapeutics Corp.