IMP321, a LAG-31g fusion protein, completed Phase I/II study in breast cancer.
Immutep has contracted Lonza to initiate process development of its lead clinical development-stage cancer therapy ImmuFact®IMP321 (LAG-3Ig), using Immutep’s own newly developed cell line. The firm’s agreement covers cell line selection, master cell banking, and process development.
IMP321 is an antigen-presenting cell (APC) activator comprising a LAG-31g fusion protein, which is generated in Chinese hamster ovary cells. The candidate has successfully completed a Phase I/II study combined with pactlitaxel chemotherapy as first-line treatment of metastatic breast cancer. Immutep is now planning a Phase IIb/III paclitaxel combination study for the metastatic breast cancer indication.
IMP321 is separately being evaluated in four separate Phase I/II melanoma and prostate cancer studies as a cancer vaccine adjuvant. Additional studies combining IMP321 with different chemotherapies in a range of cancers are expected to follow. Immutep says it is also in discussions with potential partners.
“The mechanism of action of this synergistic combination of chemotherapy and active immunotherapy is very simple,” explains Frederic Triebel, M.D., Immutep’s scientific and medical director. “The chemotherapy provides a burst of tumor cell debris and the surrounding APCs take up the tumor antigens. IMP321 activates these APCs resulting in a long-lasting CD8 T-cell response against the tumor. We think that the combination of first-line standard chemotherapy plus IMP321 should be tested in several first-line indications.”
Immutep is developing immunostimulatory factors for treating cancer and immunomodulatory therapeutic antibodies for the treatment of cancer and autoimmune diseases. The products are all based on pathways involved in the lymphocyte activation gene-3 (LAG-3) immune control mechanism. In addition to IMP321, the firm’s pipeline includes ImmuTune®IMP701, an anti-LAG-3 antagonist antibody that stimulates T-cell proliferation and inhibits regulatory T cells. ImmuTune® 731 is an anti-LAG-3 antibody designed to deplete LAG-3 positive cells, which is in development for autoimmune diseases. The candidate was licensed to GlaxoSmithKline in 2011.