Atezolizumab + Vidutolimod

The combination of atezolizumab and vidutolimod is an investigational cancer treatment that combines two distinct mechanisms of action. Vidutolimod is a Toll-like receptor 9 (TLR9) agonist designed to activate tumor-associated plasmacytoid dendritic cells, while atezolizumab is a PD-L1 inhibitor. This combination has been studied in clinical trials for various cancer types, particularly in patients who have progressed on previous PD-1 or PD-L1 blockade therapy. ## Mechanism of Action Vidutolimod (CMP-001) is a CpG-A oligodeoxynucleotide packaged within a virus-like particle. It activates plasmacytoid dendritic cells via TLR9, inducing an interferon-rich tumor microenvironment and anti-tumor CD8+ T cell responses[4][6]. When combined with atezolizumab (a PD-L1 inhibitor), the dual approach aims to enhance antitumor immune responses through complementary immune-activating effects[4]. ## Clinical Development The combination has been investigated in clinical trials, including a phase 1b study (CMP-001-003; NCT03438318) in patients with advanced non-small cell lung cancer (NSCLC) who had progressive disease after anti-PD-1 or PD-L1 therapy[4]. The study evaluated the safety and efficacy of vidutolimod and atezolizumab with and without radiation therapy. ## Safety Profile The most common treatment-related adverse events observed in clinical trials included flu-like symptoms and hypotension[4]. Intratumoral injections of vidutolimod were administered successfully, including injection of visceral lesions. Reactions following intratumoral injections typically occurred within 12 hours and included fever, tachycardia, chills, and hypotension[8]. ## Clinical Efficacy In the phase 1b study for NSCLC, no objective responses were observed in the combination arm without radiation therapy, with 23.1% of patients achieving stable disease as best response. In the combination arm with radiation therapy, 50.0% of patients had stable disease as best response[4]. The study was stopped due to lack of objective responses, though some patients showed tumor shrinkage (<30% decrease in tumor size).

Brand names

Tecentriq

Other names

CMP-001 + Tecentriqvidutolimod + atezolizumab