Pro-Cure’s activities are now focused on value-adding target validation studies ahead of drug development, opportunities which we seek to develop through a combination of partnership, collaboration and out-licensing.

Target validation is the process by which a cellular molecule, a protein in most cases, is confirmed as a “druggable” target. For example, if a specific protein inside or on the surface of cancer cells is found (i.e. following target validation) to be crucial to the viability and/or proliferative characteristics of the cell, then it represents a target against which therapeutic molecules can be directed. A good example of this is seen in the case of the breast cancer drug Herceptin, an antibody which targets HER-2 receptors on the external surface of breast cancer cells in a sub-set of breast cancer patients. The up-regulation of this receptor is integral to the viability of these cancer cells and its inhibition provides a means by which these cells can be killed or their viability reduced.

Target validation takes places in a number of stages and on a practical level is finally confirmed during Phase II and III clinical trials, when the efficacy of new potential drug molecules is tested. In the laboratory, target validation usually starts with living cells in-vitro (in-vitro validation), leading on to in-vivo studies (in-vivo validation), where the latter represent a “living” model of the disease in animals, ahead of further studies in animals and man.

Pro-Cure is now gearing up to undertake in vitro validation, using the in-house developed prostate cancer stem-cell models. These models are an accurate and viable representation of the disease which places the Company is in a unique position as the models are not available in any other laboratories.

Further target validation studies include the use of siRNA-based methods, which are used to selectively target and inhibit the synthesis of specific proteins which are indicated to be essential to the viability of the cancer cells. There have also been recent reports of siRNA being directed against prostate cancer in man and therefore, siRNA used by Pro-Cure during its validation studies may offer immediate opportunities to siRNA-based therapy, a therapeutic field which is quickly gathering momentum. Pro-Cure has developed vectors which can effectively introduce genes and siRNA into prostate cancer stem cells. Known antibodies will also be directed against some of Pro-Cure’s extra-cellular targets, which will provide the company with immediate and valuable data on new potential antibody therapies for prostate cancer. This also applies to so-called second medical use targets, which offer valuable near-market opportunities.

Target validation is essential to Pro-Cure’s value-adding activities ahead of commercialisation. Whilst the value of its current targets might be valued in tens of £000s each, their value will increase dramatically post validation, particularly where antibody data is generated for external receptors on cancer stem cells, as this will enable partnering companies to rapidly progress subsequent development activities. Post-validation data will increase the immediate value of new drug targets by an order of magnitude or more and will allow the negotiation of success-based licensing agreements based on milestone payments and longer term royalties.