Background - Immunotherapy with immune checkpoint blockers (ICB) is effective against several malignancies, but only a fraction of patients achieves clinical benefit. Identification of innate resistance mechanisms is crucial to improve the rate of response.
Hypothesis - Assessment and pre-clinical targeting of main immunosuppressive mechanisms in the tumor microenvironment (TM) may lead to more effective immunotherapeutic combinations.
Aims -
1. A retrospective bio-molecular characterization of immunosuppressive cells and matricellular proteins in TM of four tumors, triple negative breast cancer (TNBC), head and neck (HNSCC), melanoma and colorectal cancer (CRC). The immunosuppressive TM will be evaluated even in pre- and post-chemotherapy (CT) lesions from patients receiving neoadjuvant therapy; 2. exploit mouse models for testing synergistic anti-tumor activity of ICB combined with drugs targeting the immunosuppressive TM. Combinations will be based on results from Aim 1 as well as on available off-the-shelf drugs known to target the TM; 3. To design phase Ib clinical study in TNBC, HNSCC, melanoma and CRC assessing activity of ICB associated with microenvironment modulators chosen according to results of Aim 1 and Methods - TM will be analyzed by IHC, multi-parametric fluorescence-based digital pathology analysis, flow cytometry in freshly isolated surgical specimens, qPCR on FFPE tissues and interrogation of gene expression data. Models based on transplantable and spontaneous tumors will be used to test the activity of radiotherapy and drugs known to target immunosuppressive cells and matricellular proteins.
Expected results - Pre-clinical results supported the analyses of gene expression data to discriminate patients that could be directly treated with ICIs from those for which the chemotherapy is required to convert the immunosuppressive microenvironment. In particular, the discovery of novel targets whose expression is deregulated following standard chemotherapy, offered the possibility to target in a more specific way the immunosuppressive environment responsible for treatment failure.