Immutep
Immutep Ltd is a biotechnology company working primarily in the field of cancer immunotherapy using the LAG3 immune control mechanism. The company was originally built on CVac, a therapeutic cancer vaccine. In late 2014 the privately held French immunotherapy company Immutep SA was purchased by Prima Biotech.
Prima currently has three main products in its pipeline, all acquired with Immutep:
Eftilagimod alpha, which is recombinant soluble LAG-3, used as an activator of antigen presenting cells. This product has completed a Phase IIa clinical study, where it doubled the expected response rate in HER2-negative metastatic breast cancer.
IMP731, a depleting monoclonal antibody for autoimmune diseases, targeting LAG-3+ activated T cells. This antibody has been licensed to GlaxoSmithKline.
IMP701, an antagonist monoclonal antibody to LAG3 for use in cancer. This product has been licensed to Novartis.
History
Immutep originated from four early-stage biomedical research projects which scientists at the Austin Research Institute, a medical research facility then associated with Melbourne's Austin Hospital were working on in the late 1990s. These projects were packaged together and taken public in July 2001 on the ASX in a reverse takeover of a defunct mineral explorer called Prima Resources. The most advanced of these projects is what became CVac.CVac
was taken into the Phase II 'CAN-003' study in epithelial ovarian cancer in July 2010. In September 2013 Prima reported top-line interim data from this trial which showed no observed difference between treatment and control group in terms of progression-free survival ; however, in May 2014, when Prima reported final data from CAN-003, it was able to show median PFS for CVac patients in second remission of 12.91 months versus 4.94 months for the control group. This result had statistical significance. After this data was received Prima sought to alter its clinical trial protocols in order to recruit second remission patients, however in February 2015 the company announced that it was no longer recruiting into its CVac studies. Prima reported final Overall Survival numbers for CVac in May 2015 showing that median survival number for second remission CVac patients had still not been reached at 42 months, versus the median for the treatment group of 25.5 months. The p value for this comparison was 0.07.Immutep acquisition
Since February 2015 Prima's main focus has been on the programs that it acquired with Immutep. Prima had announced the acquisition of Immutep in October 2014 and completed the transaction in December 2014. The final purchase price was US$25 million. Immutep, which had been founded in 2001 by Professor Frédéric Triebel, had been built on LAG3, an immune checkpoint molecule known to play a role in switching off an immune response. Triebel had discovered LAG-3 in 1990 and over the course of the next decade, as part of a collaboration between Institut Gustave Roussy and Merck Serono, Triebel et al., established LAG-3's mechanism of action in T cells and dendritic cells. Immutep had called its soluble LAG-3 immune system activation technology 'ImmuFact' and its LAG-3 antagonist antibody technology 'ImmuTune'. It also developed a technology platform called ImmuCcine which involved covalently linking an antigen to IMP321 in a fusion protein in order vectorise the antigen to dendritic cells. Currently Immutep are only focus on the ImmuFact and ImmuTune platforms.Eftilagimod alpha
is a soluble dimeric recombinant form of LAG-3, being a fusion protein with immunoglobulin, designed to activate antigen presenting cells. Immutep established in 2008 that the product could induce activation of dendritic cell and monocytes, resulting in T cell expansion. Phase IIa data in metastatic breast cancer, generated in 2010, has suggested that IMP321 works as a chemo-immunotherapeutic, where chemotherapy creates tumour debris, and IMP321 increases activation of APCs as they take up that debris. In that study, IMP321 increased the response rate according to the RECIST criteria from the 25% rate expected for paclitaxel to over 50% at the six-month mark. There is also evidence that IMP321 at low doses can be used as a T cell adjuvant for cancer vaccines.Immutep has initiated a Phase IIb study of IMP321 in hormone receptor-positive metastatic breast cancer. Prima has registered a Phase I study in conjunction with an existing approved checkpoint inhibitor pembrolizumab in late stage melanoma.