PRE-CLINICAL DATA CONFIRMS RADIO- ENHANCING POTENTIAL OF NOX66 FOR PAEDIATRIC BRAIN CANCER
• Diffuse Intrinsic Pontine Glioma (DIPG); highly aggressive and poorly responsive brain cancer of children
• Idronoxil (NOX66) significantly enhances ability of radiotherapy to kill DIPG cells.
Sydney, 5 July 2018: Noxopharm (ASX: NOX) today releases pre-clinical data providing important proof-of-concept of the ability of idronoxil (the active drug in NOX66) to increase the killing effect of radiation on brain cancer cells.
The data has been generated via a collaboration with the Children’s Cancer Institute (CCI) and is part of a broader program being conducted by Noxopharm into the use of idronoxil (as NOX66) as a radio-enhancer in the treatment of both primary and secondary brain cancers in adults and children. This particular collaboration with the CCI is looking at using NOX66 to enhance the ability of radiotherapy to treat diffuse intrinsic pontine glioma (DIPG), a highly aggressive and poorly responsive primary brain cancer of children.
Laboratory studies were conducted using primary cell cultures established by CCI from DIPG tumours. Idronoxil was able to kill these cancer cells on its own, but more importantly, sensitised the cells to radiation, leading to a significantly higher level of death of cancer cells using a constant dosage of radiation.
NOX66 brain cancer program
NOX is pursuing a broad program looking at the potential to use NOX66 to treat brain cancers in adults and children based on the following:
• The ability of idronoxil to readily cross the blood-brain barrier in animals
• The ability of idronoxil to kill highly chemotherapy-resistant glioblastoma multiforme (GBM)
cancer cells
• The ability of idronoxil to kill GBM cells regardless of their MGMT gene expression
• The ability of idronoxil to sensitise cancer cells to radiation.
DIPG
DIPG is the most aggressive of all childhood cancers and is the leading cause of brain tumour-related
death in children. There is no effective treatment for DIPG and all patients eventually die from this disease.
Radiotherapy is the only form of treatment currently that offers any transient benefit in
DIPG. Approximately 90% of cases of DIPG respond to radiotherapy, but the responses generally are
short-lived, lasting on average 6-9 months. DIPG arises in an area of the brain known as the pons, a
part of the brainstem which controls many of the body’s vital functions such as breathing and heart
rate. The critical nature of these functions serves to limit the amount of radiation that can be
applied. Following completion of radiotherapy, almost all DIPG cases recur locally within 12 months.
NOX and DIPG
Finding a way to render the DIPG cells more sensitise to radiation, without rendering the
surrounding healthy brain tissue more radio-sensitive as well, has been identified as an urgent need.
Noxopharm believes that NOX66 holds the potential to meet that need, and today’s data goes
towards supporting that belief. The pre-clinical program now enters the animal phase where DIPG
tumours will be grown in the brains of mice (orthotopic xenografted tumours) and treated with a
combination of NOX66 and radiotherapy. Success in that animal model opens the way for a clinical
study in children.
Comment
Dr John Wilkinson, Noxopharm Chief Scientific Officer, said,” Today’s data fits in with other data
showing idronoxil increasing the killing effect of radiation on lung and prostate cancer cells by 2- or
3-fold. The radio-enhancing effect of idronoxil therefore is looking to be independent of cancer type.
On that score, it is worth noting that DIPG arises in the brain’s glioma cells, or cells that provide the
support structure of the brain. And these are the same cells involved in glioblastoma multiforme
(GBM), the most common form of aggressive brain cancer in adults.”
“That feeds into our broader objective of using NOX66 to sensitise primary brain cancer such as GBM
in adults, as well as secondary brain cancers, in a way that allows the radiotherapy to be more
effective, but without jeopardising the safety of healthy brain tissue.”
“Treatment of children with DIPG currently relies mainly on radiotherapy, but the location of DIPG in
the vitally important brainstem means that the amount of radiation that can be delivered needs to
be limited and that accounts for the poor survival outcome with this cancer. Our aim with NOX66 is
to provide a means of achieving greater killing of DIPG cells, equivalent to giving a higher dosage of
radiotherapy but without inducing any more harm on healthy brain tissue. And obviously we hope to
see that translate into longer survival,” Wilkinson added.
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NOX Price at posting:
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