Cavrotolimod Receives Fast Track Designations in Non-Melanoma Skin Cancers
Posted: Wednesday, January 20, 2021
Recently, the U.S. Food and Drug Administration (FDA) granted two Fast Track designations to the Toll-like receptor 9 agonist cavrotolimod (AST-008) in non-melanoma skin cancers. The first indication is for cavrotolimod in combination with anti–PD-1 therapy for patients with locally advanced or metastatic Merkel cell carcinoma refractory to prior anti–PD-1 blockade. The second indication is for cavrotolimod in combination with anti–PD-1/anti–PD-L1 therapy for patients with locally advanced or metastatic cutaneous squamous cell carcinoma refractory to prior anti–PD1/PD-L1 blockade. This agent is designed to activate a patient’s innate and adaptive immune systems to potentially induce anticancer immune responses.
A phase Ib dose-escalation stage of an open-label, multicenter trial is evaluating the safety, tolerability, pharmacokinetics, pharmacodynamics, and preliminary efficacy of intratumoral cavrotolimod injections alone and in combination with intravenous pembrolizumab in patients with advanced solid tumors. These tumors included advanced or metastatic Merkel cell carcinoma, head and neck squamous cell carcinoma, cutaneous squamous cell carcinoma, melanoma, and leiomyosarcoma.
Summarized here are key highlights from the phase Ib stage of the trial:
- No serious treatment-related adverse events or dose-limiting toxicities were observed.
- The confirmed overall response rate was 21% in the phase Ib dose-escalation stage across all doses.
- The confirmed overall response rate was 33% with the highest dose (32 mg), which was selected as the phase II recommended dose.
- Overall responses occurred in two patients with advanced Merkel cell carcinoma.
- Durable and ongoing responses yielded a progression-free survival exceeding 6 months in all four responders and 16 months in two responders.
- The researchers observed dose-dependent activation of key immune cells, including cytotoxic T cells and natural killer cells, as well as increases in cytokine/chemokine levels in patients’ blood after cavrotolimod monotherapy and combination therapy with cavrotolimod plus pembrolizumab.