ValiRx is also evaluating a novel peptide that is under development by CRT for treatment of refractory prostate cancer. Depending on the commercial viability of producing a therapeutic agent from the peptide, ValiRx may in-license the technology, called ARP. A drug compound based on the peptide has the potential of becoming a significant treatment option for patients exhibiting androgen independent prostate cancer.

The peptide specifically inhibits androgen, estrogen and epithelial growth factor dependent DNA synthesis and has in pre-clinical studies shown to be highly effective against prostate and breast cancer. Although androgen withdrawal can control prostate cancer for long periods in many patients, controversy exists regarding management when the tumor becomes androgen independent.

Prostate Cancer (PCA) is the 3^rd most common cancer in the world. In the USA alone 234,460 men were diagnosed with PCA in 2006 with 27,350 estimated deaths. In prostate cancer, Testosterone triggers association of the androgen receptor with Src in cells prompting DNA synthesis and cell growth. First line treatment for PCA is Hormone Therapy (either to prevent production of testosterone or block its interaction with the androgen receptor) in combination with radiotherapy or radical surgery. Established hormone therapy drugs include Zoladex, Casodex and Lupron all of which have over a billion dollar sales. Significant side effects are associated with hormone therapies including impotence (during treatment and a period of time after treatment), tumour flare and bone thinning.

Initial response to hormone therapy may be good, however many patients rapidly develop hormone refractory and metastatic PCA. In this case Taxotere is the first and only line of treatment. However the extremely poor prognosis for hormone-refractory prostate cancer (HRPC) patients (<50% survival at 2 yrs) presents a major unmet clinical need with, arguably, the opportunity for therapeutic intervention at the early stages of PCA progression where an “active monitoring” approach is currently adopted due to the risk/benefit considerations of available treatments at this stage of the disease.