BioWorld International Correspondent

PARIS - Immutep SA closed a second round of funding in which it raised €2.5 million from two Paris-based venture capital funds.

The financing was led by Innoven Partenaires SA using one of its own funds, Innoven FCPI 6, as well as two funds it manages on behalf of the French Post Office group: FCPI Poste Innovation 2 and 3. The balance was provided by H21, a biotechnology fund managed by Equitis SA.

Innoven Partenaires put up the entire €2.5 million (US$3.3 million) Immutep raised in its initial round in April.

Immutep, which was founded in 2001 and is based in Orsay, southwest of Paris, is still hoping to raise another €2 million or €3 million, said John Hawken, co-founder and CEO.

"We are keeping the funding round open on the same conditions," he told BioWorld International, adding that discussions were taking place with other potential investors, and he hoped to reach agreements before the middle of the year.

In addition, Immutep has applied for a grant of €1 million from France's National Research Promotion Agency (Anvar), and Hawken said he was "very confident" of a positive response within the next month or two.

Immutep is developing therapeutic vaccines based on the natural human protein LAG-3, a stimulant of antigen-presenting cells, especially dendritic cells, for the treatment of cancer, infectious diseases and allergies. In combination with the appropriate antigen, LAG-3 acts as a natural immunostimulant in therapeutic vaccination, boosting the T-cell immune response necessary for killing tumors and infected cells.

The company has developed three product platforms that exploit the action of LAG-3 in the regulation of the immune system. The first two, ImmuFact and ImmuCcine, harness the immunostimulatory properties of the free molecule to create therapeutic vaccines. Both technologies amplify the immune response to antigens by increasing the efficiency of dendritic cells. The third platform exploits the properties of the membrane-bound molecule on activated T cells and regulatory T cells to modulate the T-cell response.

Proof of concept has been established in animal models of three tumors, as well as in infectious diseases, such as HIV and hepatitis B virus. Immutep is applying the same therapeutic approach to the treatment of allergies and asthma.

Its lead compound, IMP321, is a product of its ImmuFact platform. It is a T-cell immunostimulatory factor derived from the soluble form of LAG-3, which binds with high affinity to MHC Class II molecules expressed by dendritic cells. It generates an antitumor or antiviral cytotoxic T-cell response when injected in conjunction with tumor cells or protein or DNA antigens. IMP321 has a wide variety of potential applications, but initially is being developed for the treatment of prostate cancer and HBV.

Thanks to the additional funding, Immutep plans to initiate Phase I/II trials of IMP321 in the second quarter. It will begin with a proof-of-principle Phase I trial of IMP321 alone (not loaded with any antigen) starting in April, followed by benchmarking trials with the hepatitis B surface antigen and the influenza split-virus antigen.

Therapeutic trials probably would start in 2006, but would be carried out by third parties, since Immutep already had found partners for the application of IMP321 in both HBV and prostate cancer. Hawken said that since its technology can be used in a variety of applications, the company had identified more than 50 potential partners, mostly in the U.S., and that it was negotiating with several of them. He expects the first collaborative deals to be signed within the next few months.

Immutep will continue to develop IMP321 for the treatment of other cancers.

Its ImmuCcine platform still is at the research stage. It entails covalently linking an antigen to IMP321 in a fusion protein, resulting in vectorization of the antigen to the DC, in addition to the immunostimulatory effect. It says the dual-action vaccines could be particularly effective in difficult pathologies, such as HIV. Two products so far have emerged from the program - IMP361 and IMP362 - one or both of which could be taken into preclinical development in 2006.

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