Interim data from a Phase 1b/2 trial combining the intratumoural TLR-9 agonist SD-101 with pembrolizumab demonstrated that the combination is well tolerated and leads to increased tumour immune cell infiltration, as well as inducing tumour shrinkage, in injected and uninjected lesions—including those in distant metastases.65,66 Pembrolizumab is also being investigated in a Phase 2 trial with intratumoural tavokinogene telseplasmid78,95 and in a Phase 1b trial with the oncolytic virus CVA21. This evidence concerns the gene TLR9 and neoplasm.