Australian company Immutep gets clinical trial funding support from Merck and Pfizer.

Australian-based Immutep is developing immunotherapeutic products for the treatment of cancer and autoimmune disease. Its lead candidate is eftilagimodalpha (“efti” or “IMP321”), a soluble LAG-3Ig fusion protein based on the LAG-3 immune control mechanism. This mechanism plays a vital role in the regulation of the T cell immune response. IMP321 is currently in a Phase IIb clinical trial as a chemoimmunotherapy for metastatic breast cancer and a Phase I combination therapy trial in metastatic melanoma.

Immunoep recently announced that the firm has entered into a clinical trial collaboration and supply agreement with Merck KGaA, Darmstadt, Germany and Pfizer Inc., to evaluate the combination of IMP321 with avelumab, a human anti-PD-L1 antibody, in patients with advanced solid malignancies.

MP321 is a MHC class II agonist that activates antigen-presenting cells (“APCs”) such as dendritic cells and monocytes (primary target cells) and then CD8 T-cells (secondary target cells). The activation of the dendritic cell network and the subsequent T cell recruitment at the tumor site with MP321 may lead to stronger anti-tumor CD8 T cell responses than observed with checkpoint inhibitor monotherapy. In combination with chemotherapy, the activation of the APC network with MP321 the day after injection of a single agent chemotherapy, may lead to stronger cytotoxic cellular responses associated with an improved long-term Th1 (IFN-γ) immune status, according to Immutep. 

Avelumab, which is being co-developed and co-commercialized by Merck and Pfizer, has been shown in preclinical models to engage both the adaptive and innate immune functions. It has received accelerated approval by the US Food and Drug Administration (FDA) for the treatment of patients with metastatic Merkel cell carcinoma (MCC) and previously treated patients with locally advanced or metastatic urothelial carcinoma (mUC), and is under further clinical evaluation across a range of tumor types.

The clinical evaluation of IMP321 with avelumab will be an amendment to the existing INSIGHT Phase I clinical trial and will evaluate the safety, tolerability and recommended Phase II dose of IMP321 when combined with avelumab in patients with advanced solid malignancies. 

“We continue to focus on opportunities to advance combination trials with avelumab, as we believe the pathway to progress in immuno-oncology lies in combination approaches,” said Chris Boshoff, M.D., Ph.D., Senior Vice President and Head of Immuno-Oncology, Early Development, and Translational Oncology, Pfizer Global Product Development.