Phoenix Biotechnology, Inc., a San Antonio, Texas based biotechnology company, was incorporated in Texas in 2003 to develop promising agents with minimal or no side effects for targeted therapy of malignant tumor growth. Targeted therapy has recently become the focus in the medical community for the treatment of oncologic diseases. Pharmaceutical companies are seeking to develop drugs that target particular and discrete targets in tumor cells providing maximum efficacy yet without affecting healthy cells.
PBI-05204 is just such a drug. Following a tradition of investigating plant sources for medicinal drugs, Phoenix Biotechnology has developed a patented modified supercritical CO2 extract of Nerium oleander that has been found both in vitro and in vivo to bind to just such discrete cellular targets in solid tumors.
Our USFDA Open Label Phase I Trial of PBI-05204 in Advanced Cancer Patients at M.D. Anderson Cancer Center has demonstrated that PBI-05204 does indeed bind to selected specific cellular tumor cell targets causing cellular downstream changes to certain signal transduction pathways, but not to healthy cells. The primary target, with downstream targets as well, is a particular subtype of the Na,K-ATPase enzyme known as alpha-3. Phoenix Biotechnology research has shown that PBI-05204 has a strong affinity for tumor cells that express a relative abundance of this particular subunit. As an example, as colon cells undergo a change from a normal phentotype to a malignant phenotype they express the alpha-3 subunit. This then makes the malignant cells unique targets for PBI-05204 while sparing normal cells.
A summary of responses for the initial 20 patients in the Phase I trial was stable disease in 9/20 patients (45%) with various tumor types after first restaging (2 months). Out of these, minor response was seen in 3 patients-one each with colorectal (17% decrease), bladder (11% decrease), and fallopian tube cancer (10% decrease). A follow up Phase II clinical study of PBI-05204 was conducted in advanced pancreatic cancer patients at five separate sites across the United States. In these heavily pretreated patients PBI-05204 showed once again it was safe and, in addition, provided a few minor responses in this extremely tough type of malignant disease.
In the neurological disease and disorder field, including ischemic stroke, Alzheimer's, and Huntington's, research has been conducted at Duke University on PBI-05204 and some of its further fractionated compounds absent cardiac glycosides. These studies have provided evidence that the neuroprotective activity of PBI-05204 is mediated through oleandrin and/or other cardiac glycoside constituents, but that additional, non-cardiac glycoside components of PBI-05204 may also contribute to the observed neuroprotective activity. Finally, we show directly that both oleandrin and the protective activity of PBI-05204 are blood brain barrier penetrant in a novel model for in vivo neuroprotection. The specific upregulation of brain derived neurotrophic factor (BDNF), a critically important brain growth factor, is a major reason why oleandrin can provide brain health advantages. Together, these findings suggest clinical potential for PBI-05204 in the treatment of ischemic stroke and prevention of associated neuronal death.
A third area of recent focus has investigated the antiviral properties of PBI-05204. To date we have identified potent antiviral activity against Ebola and Marburg viruses, cytomegalovirus, Herpes simplex viruses, HIV and HTLV-1. We believe this area of research is extremely important and is worthy of further pursuit.
Finally, a recent third party evaluation or the potential value of Phoenix Biotechnology, Inc. has placed focus on three areas that are suitable for potential orphan drug status. These are 1) cancer (specifically, glioblastoma), 2) stroke and neurodegenerative diseases, and 3) certain viral diseases where few, if any, other drugs are presently evaluable.
The Company is focusing its research efforts to develop products that conform with the new paradigm for the socially responsible approach to the treatment of cancer as described by the National Cancer Institute.
The new paradigm seeks to develop therapeutic agents and treatment regimens that will enable physicians to eventually deal with cancer as a chronic condition rather than an acute condition and enable patients to live extended lives with a high or improved quality of life.