Systemic Therapeutic 

Biosceptre’s systemic therapeutic application is at an early development stage. The defined exit point for this program is after completion of a Phase I clinical trial in one cancer indication.

The Company has already identified three lead antibodies to take forward into xenograft mouse studies. These antibodies were selected based on results from in vitro experiments which determined live cell binding in all 28 cell lines tested and in vitro cell death in the 15 different cell lines tested.

The DNA sequences of the lead antibodies (consisting of two domain antibodies and one monoclonal antibody) are being cloned, with stable clones of these antibodies to be used in the xenograft mouse studies and also in external studies by pharmaceutical industry partners conducting their own in-house studies.

The purpose of the xenograft mouse studies is to evaluate whether the antibodies inhibit cancer cell growth and/or resolve tumors in vivo. The design of the studies incorporates the results of lead-up in vitro data as well as published data from similar studies using antibody preparations. Variables to be tested in the xenograft mouse studies include:

• antibody dose size
• frequency of dosing
• stability of the antibody preparation
• appropriate strains of mouse and types to be tested
• antibody interactions
• combination therapy of antibodies and chemical compounds

Biosceptre has hired an Australian CRO to perform the initial studies and expects this phase of the work to be completed within twelve months. The program will consist of a number of specifically designed xenograft studies, supported by in vitro QA and QC assays.

When the xenograft mouse studies are completed, Biosceptre will choose one lead antibody for scale up and production and take it forward into acute toxicity studies in larger mammals. Results of acute toxicity testing will be part of an IND package the Company will submit to the FDA.

After the completion of acute toxicity testing, the next step is a “first in man” study (Phase I clinical trial) in one cancer indication, this being the Company’s defined endpoint for this program.

In Vitro Diagnostic Prostate Immunohistochemistry (IHC) Test

The Company is developing a diagnostic test for prostate cancer that can be performed on tissue samples. While the ubiquitous nature of nf-P2X₇ makes it useful as a diagnostic marker for virtually all cancers, Biosceptre plans to focus initially on developing tissue-based tests that offer significant competitive and clinical advantages. Prostate cancer has been chosen as the lead indication because this relatively common cancer affects hundreds of thousands of men worldwide but is treatable if caught at an early stage. Biosceptre's Prostate IHC diagnostic test assists the clinician in being able to differentiate between clinically significant (high risk) and clinically insignificant (low risk) forms of the disease.

The ability of the test to differentiate between high risk and low risk tumors due to the presence of basal cell staining (see figure below) provides additional information for the urologist, where clinically significant tumors are more likely to require immediate medical intervention. For patients with low risk tumors, treatment costs are reduced because these patients can be placed on a "watchful waiting" program, rather than undergoing aggressive treatment.

There is also the opportunity to develop additional IHC tests which target a broad range of cancer types. One monoclonal antibody has been selected for use in IHC diagnostic testing and this single antibody is capable of detecting all human cancers that have been tested to date.