CONJUCHEM DEVELOPS NEW PLATFORM, PC-DAC™ FIRST CLINICAL CANDIDATE, PC-DACTM:EXENDIN-4, TO ENTER CLINIC IN Q1 2006

Montreal, Canada, August 24, 2005 – ConjuChem Inc. (TSX: CJC) today announced that it will be progressing into clinical development the first compound from its new platform technology, PC-DAC™ (Pre-formed Conjugate-Drug Affinity Complex). Pre-formed conjugates represent a natural extension of ConjuChem’s core DAC™ platform technology, and builds on the Company’s considerable albumin bonding expertise and intellectual property. Both DAC™ peptides and now PC-DAC™ peptides are designed to retain the therapeutic activity of the original peptides, with a much longer duration of activity.

ConjuChem’s core DAC™ Technology creates DAC™ peptides (e.g., DAC™:GLP-1, DAC™:GRF) which are engineered to covalently attach to albumin (bioconjugation), the dominant protein in blood serum and broadly recognized as an important drug carrier.  This covalent attachment to albumin can occur inside the body (in vivo bioconjugation) as a subcutaneous injection of the DAC™ peptide reacts to endogenous albumin. Or, as in the case with the new PC-DAC™ Technology, outside the body (in-vitro bioconjugation) as the DAC™ peptide reacts to an external source of albumin to form the drug product (PC-DAC™ peptide) which is subsequently injected subcutaneously.

In-vitro bioconjugation for developing Pre-formed Conjugates has only become a viable option recently for ConjuChem in human applications because previously the only available albumin was purified from human serum. Despite its abundance, this human derived source of albumin cannot be used as part of a drug product due to safety concerns inherent to the source. ConjuChem selected Delta Biotechnology Ltd.’s Recombumin® as its GMP-grade human recombinant albumin source due to its clear leadership in the field.

Developed to complement the original core DAC™ Technology, PC-DAC™ is intended to create new therapeutic opportunities for ConjuChem. One of the principal advantages of PC-DAC™ technology is that it ensures that essentially all DAC peptide is bound to cysteine 34 of albumin. Based on pre-clinical data generated to date the Company expects a significant improvement in tolerability which will allow for less frequent dosing (up to a week or more) when the dose might otherwise be limited due to side effects with the in-vivo technology. .

 

The initial PC-DAC™ project candidates are PC -DAC™:Exendin-4 and PC-DAC™:Insulin.  The Company expects to dose its first patients with PC -DAC™:Exendin-4 in Q1 2006 . The pre-clinical studies have produced very encouraging data, showing a significantly longer duration of action and an improved tolerability profile for PC-DAC™:Exendin-4 as compared to Exendin-4.  This data supports a human dosing interval of once a week or longer.  PC-DAC™:Exendin-4 is expected to be stable in an injectable solution at room temperature, thus being highly convenient for patients. The additional costs associated with Recombumin® are offset by the fact that the product is stable in solution and will not require lyophilization

 
“Combining DAC™ peptides with albumin before injection, thereby creating PC-DAC™ Peptides, allows the DAC™ Technology to be applied to a broader range of therapeutic peptides, including those which were difficult to develop through an in vivo bioconjugation approach,” said Dr. Jean-Paul Castaigne, Chief Operating Officer of ConjuChem. “With our first clinical candidate, PC-DAC™:Exendin-4, we expect to see a long-acting compound with an excellent tolerability and safety profile, including minimal to no nausea and improved immunogenicity when compared to other exendin-4 peptides not bound to albumin.”

ConjuChem’s ongoing DAC™:GLP-1 Phase 1b/2a program with a new diluent continues to make progress. Positive interim results from this program demonstrated a significant improvement in the drug’s tolerability profile. Conjuchem expects to announce, before the end of September 2005 an update on this program and its impact on the design of a pivotal Phase IIb trial.

 

As well, the Company intends to initiate a Phase 2 study for DAC™:GRF in Q4 2005, Conjuchem’s second compound in development using its in-vivo bioconjugation technology. The initial indications in adults will be HIV lipodystrophy and visceral obesity with metabolic syndrome and GHD in children. The drug product will be administered once a week in the first trial and subsequent trials will investigate longer dosing intervals.

 

Recombumin® was developed by Delta Biotechnology Ltd. to prevent transmission of viruses or prions from human donor to pat ient. Recombumin® is a 20% rHA (recombinant human albumin) produced in the yeast Saccharomyces cerevisiae that is currently approved as an excipient and in development for other uses i.e. children’s vaccine. Several studies have been published showing excellent safety and tolerability in more than 500 subjects.  Due to the purity and consistency of Recombumin®, the efficiency of the bioconjugation of DAC™ peptides to it is greater than with purified human serum albumin.

   

About ConjuChem

 

ConjuChem, developers of next generation medicines from therapeutic peptides, is creating long-acting compounds based on bioconjugation platform technologies. When applied to peptides, the Company's systemic DAC™ Technology enables the creation of new drugs with significantly enhanced therapeutic properties as compared to the original peptide. The Company is developing compounds to treat various disorders including diabetes, human growth deficiencies, HIV/AIDS, and congestive heart failure.

Detailed descriptions of the Company can be viewed on the Company's website www.conjuchem.com.

About Delta Biotechnology Ltd

Delta Biotechnology Ltd, a wholly owned subsidiary of Sanofi-Aventis, is based in Nottingham , UK . The core business is the animal-free development and large-scale manufacture of therapeutic recombinant proteins through world-leading manipulation of  baker’s yeast, Saccharomyces cerevisiae.  They also license protein expression and albumin fusion technology for the production of biotherapeutics with partners in the US and Japan

Delta has established a substantial body of knowledge in recombinant protein expression, fermentation and purification technologies. Coupled to R&D capabilities, Delta operates a cGMP, FDA-inspected facility based around an 8,000L working volume fermenter which is used for the manufacture of their lead product, Recombumin®, recombinant human albumin, the world's first biotech excipient. Based on years of experience, Delta is the worldwide leading authority on the analysis, characterisation and production of this protein which has been shown to be of exceptional purity in comparison to the human plasma-derived analogue