New Preclinical Discovery Shows GlycoGenesys' Cancer Drug Candidate GCS-100 Inhibits AKT1 (Promoter of Cancer Cell Survival and

      Data Presented At The XI International Work Shop on Chronic
                         Lymphocytic Leukemia

   GlycoGenesys, Inc., (NASDAQ: GLGS), a biotechnology company, today
announced that Dr. Finbarr Cotter, Professor, Barts and The London
School of Medicine UK, revealed new findings about the Company's
cancer drug candidate GCS-100 over the weekend at the prestigious XI
International Work Shop on Chronic Lymphocytic Leukemia in New York
City. The poster presentation and a corresponding abstract from the
conference were entitled "GCS-100, A Selective Galectin-3 Mediated CLL
Therapy Induces Angiogenic and AKT1 Inhibition With Caspase-9
Activation." 

   AKT1: 

   The pivotal role of AKT1 in cell survival has made it an important
target in cancer, cardiovascular, and neurodegenerative drug
discovery. Active or up regulated AKT1 in cancer cells promotes cell
survival and drug resistance and confers cell longevity in lymphomas,
leukemia's and solid tumor cancers.

   New scientific findings include: 

   --  When treated with GCS-100, a variety of lymphoma and myeloma
        cell lines, and chronic lymphocytic leukemia primary patient
        cells showed distinct down regulation of AKT1 in a dose
        dependent manner. This in vitro data shows that GCS-100 can
        inhibit the cell survival promoting effects of AKT1 in
        lymphoma cells including patient cells.

   --  The activity of VEGF, a pro-angiogenic factor was inhibited in
        cell lines when treated with GCS-100. This is significant
        because VEGF plays an important role in angiogenesis and in
        the survival, growth and proliferation of many cancer tumors
        including B cell lymphomas and chronic lymphocytic leukemia

In June 2005 

   --  Dr. Cotter published for the first time that Galectin-3 and
        Bcl-2 are co- located in malignant cell lines;
       
   --  That GCS-100 blocks Galectin-3's ability to co-locate with
        Bcl-2 in these malignant cell lines causing targeted cell
        death;

   --  And, this programmed cell death occurs through the known
        caspase-9 mediated cell death pathway;

   --  Moreover, GCS-100 induced significant programmed cell death in
        both malignant cell lines and primary patient CLL cells with
        minimal effect against normal B- cells and stem cells.

   Dr. Cotter commented, "The first clinical trial of GCS-100 for
chronic lymphocytic leukemia is planned to be initiated next month in
the U.S. and I am looking forward with enthusiasm to be a principal
investigator of the U.K. arm of the trial. GCS-100 shows real
preclinical promise to emerge as an exciting new agent for cancer
therapy. We are now obtaining greater clarity into the mechanisms of
action for GCS-100 which is considerably assisting us in designing its
application in the clinic. It is potentially an ideal therapeutic
molecule because of its tri-modal anti-cancer action which spares
normal cells from cell death." 
   Bradley J. Carver, CEO and President of GlycoGenesys, Inc. stated
"This supports the important role of Galectin-3 in AKT activation and
prevention of apoptosis in malignant cells. Targeting Galectin-3 with
GCS-100 for malignant cells is a rational therapeutic approach. These
results further support our focused clinical trial program." 

   About GlycoGenesys, Inc.

   GlycoGenesys, Inc. is a biotechnology company focused on
carbohydrate drug development. The Company's drug candidate GCS-100, a
unique compound to treat cancer, has been evaluated in previous
clinical trials at low dose levels in patients with colorectal,
pancreatic and other solid tumors with stable disease and partial
response documented. The Company currently is conducting a Phase I
dose escalation trial to evaluate higher dose levels of GCS-100LE, a
low ethanol formulation of GCS-100, at Sharp Memorial Hospital,
Clinical Oncology Research in San Diego, California and the Arizona
Cancer Center in both Tucson and Scottsdale, Arizona. In addition,
GCS-100LE is being evaluated in a Phase I/II trial for multiple
myeloma at the Dana-Farber Cancer Institute in Boston, Massachusetts
and the Lucy Curci Cancer Center in Rancho Mirage, California. Further
clinical trials are planned for 2005, 2006 and 2007. Further
information is available on GlycoGenesys' web site:
www.glycogenesys.com.

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