DOR BioPharma Launches Initiation Of Clinical Development Program For Oral Leuprolide

DOR BioPharma, Inc. (OTCBB: DORB) (“DOR” or “The Company”) announced that it plans to initiate a clinical development program in humans with its Lipid Polymer Micelle (“LPM™”) oral drug delivery technology. The LPM™ system is a platform technology designed to allow for the oral administration of drugs such as leuprolide that are water-soluble but poorly permeable through the gastrointestinal tract. DOR has previously demonstrated in preclinical animal models that the LPM™ technology is adaptable to oral delivery of peptide drugs and that high systemic levels after intestinal absorption can be achieved with the peptide hormone drug leuprolide.

In preclinical studies, DOR’s LPM™ delivery technology significantly enhanced the ability of leuprolide, to pass through the intestinal epithelium in comparison to leuprolide alone. Leuprolide is a synthetic peptide agonist of gonadotropin releasing hormone (“GnRh”), which is used in the treatment of prostate cancer in men and endometriosis in women. Leuprolide exhibits poor intestinal absorption from an aqueous solution with the oral bioavailability being less than 5%. Utilizing LPM™ in both rats and dogs, the bioavailability of leuprolide averaged 30% compared to 2.2% for the control oral solution.

Leuprolide is one of the most widely used anti-cancer agents for advanced prostate cancer in men. Injectable forms of leuprolide marketed under tradenames such as Lupron® and Eligard® had worldwide sales of approximately $1.8 billion in 2006. Injectable leuprolide is also widely used in non-cancer indications, such as endometriosis in women (a common condition in which cells normally found in the uterus become implanted in other areas of the body), uterine fibroids in women (noncancerous growths in the uterus) and central precocious puberty in children (a condition causing children to enter puberty too soon). Leuprolide is currently available only in injectable, injectable depo and subcutaneous implant routes of delivery which limits its use and utility.

The LPM™ system is a proprietary oral delivery platform technology that utilizes a lipid based delivery system that can incorporate the peptide of interest in a thermodynamically stable configuration called a “reverse micelle” that through oral administration, can promote intestinal absorption. Reverse micelles are structures that form when certain classes of lipids come in contact with small amounts of water. This results in a drug delivery system in which a stable clear dispersion of the water soluble drug can be evenly dispersed within the lipid phase. LPM™ is thought to promote intestinal absorption due to the ability of the micelles to open up small channels through the epithelial layer of the intestines that allow only molecules of a certain dimension to pass through while excluding extremely large molecules such as bacteria and viruses. The reverse micelles also structurally prevent the rapid inactivation of peptides by enzymes in the upper gastrointestinal tract via a non-specific enzyme inhibition by surfactant(s) in the formulation.

In re-initiating the LPM™ technology, DOR has enlisted the assistance of experienced drug delivery, formulation and clinical consultants who have been intimately involved with the development of the LPM™ technology.

“One of the major limitations in the development of drugs derived from synthetic peptide chemistry or recombinant DNA technology is that they must be given by injection due to their inability to penetrate the epithelial layer of the intestines,” said Christopher J. Schaber, Ph.D., President and CEO of DOR. “Given the high relative bioavailability that the LPM™ system delivers, we believe that this technology will be applicable to a large number of water soluble drugs including peptides with poor intestinal permeability, resulting in increased patient compliance and safety. With the preclinical data we have generated to date, we anticipate initiation of a Phase 1 safety, tolerability and pharmacokinetic study with LPM-leuprolide around midyear 2007. Expansion of our pipeline beyond orBec® for the treatment of GI GVHD is an important focus of our company. In addition to the follow-on clinical studies with orBec®, we are encouraged with the potential the LPM™ system has to enhance delivery across a number of therapeutic areas.”