BioWorld International Correspondent

PARIS - Immutep SA initiated a second Phase I trial of its lead compound, ImmuFact IMP321, in metastatic breast carcinoma.

ImmuFact IMP321 is a natural human T-cell immunostimulatory factor designed to amplify the T-cell immune response in therapeutic vaccines through the activation of dendritic cells and more efficient antigen presentation to T cells. Immutep in June announced the completion of a Phase I trial of the product in metastatic renal-cell carcinoma.

Immutep, which is based at Orsay, southwest of Paris, is developing therapeutic vaccines for cancer, infectious diseases and allergies based on the use of LAG-3, an immunomodulatory protein expressed on the surface of activated T cells.

The company said the new trial of ImmuFact IMP321 would be the first time that chemoimmunotherapy - chemotherapy followed by immune stimulation - has been used to treat metastatic breast cancer. Immutep points out that chemotherapy works by inducing tumor cell apoptosis and the release of tumor antigens, triggering a T-cell immune response that contributes to the regression of the tumor, but maintained that the immune response needs to be sustained and amplified by a T-cell booster that is non-toxic and can be given repeatedly.

The new trial, which is being conducted at the René Huguenin Cancer Center in Saint Cloud, near Paris, will assess IMP321 following paclitaxel.

Patients will receive weekly administrations of paclitaxel in low doses, accompanied by bi-weekly administrations of IMP321. Two dose levels of IMP321 will be studied. As well as safety and tolerability, the trial will determine relevant pharmacodynamic parameters, including CD8 T-cell responses.

Immutep also is planning a Phase I trial of IMP321 in melanoma. ImmuFact is one of three LAG-3-based product platforms developed by Immutep, the other two being ImmuCcine, which is designed to produce immunostimulatory vaccines, and ImmuTune, which uses LAG-3 specific antibodies to control signaling of the membrane-bound LAG-3 molecule into activated effector T cells or regulatory T cells to modulate the T-cell response.

Immutep is engaged in a third funding round in which it hopes to raise €13 million (US$16.7 million) by the end of the summer. Since it was founded in 2001, the company has completed two €2.5 million funding rounds, the second of which dates back to January 2005.