FDA grants fast track designation to AST-008 for skin cancer indications
The FDA granted fast track designation to cavrotolimod for two skin cancer indications, according to the agent’s manufacturer.
One designation applies to use of cavrotolimod (AST-008, Exicure) in combination with anti-PD-1 therapy for treatment of patients with locally advanced or metastatic Merkel cell carcinoma refractory to prior anti-PD-1 blockade.
The other applies to use of the agent in combination with anti-PD-1 or anti-PD-L1 therapy for treatment of patients with locally advanced or metastatic cutaneous squamous cell carcinoma refractory to prior anti-PD-1/PD-L1 blockade.
Cavrotolimod is a spherical nucleic acid toll-like receptor 9 agonist.
A multicenter, open-label trial evaluated intratumoral cavrotolimod injections alone and in combination with IV pembrolizumab (Keytruda, Merck) for patients with advanced solid tumors, including advanced or metastatic Merkel cell carcinoma, head and neck squamous cell carcinoma, cutaneous squamous cell carcinoma, melanoma and leiomyosarcoma.
Results of the phase 1B dose-escalation portion of the trial showed a 21% confirmed overall response rate, with one complete response and three partial responses reported among 19 patients. All four patients who responded to treatment achieved PFS longer than 6 months.
Two patients with advanced Merkel cell carcinoma and two with melanoma achieved response. An additional two patients with melanoma and one with cutaneous squamous cell carcinoma exhibited target tumor shrinkage.
Researchers observed no treatment-related serious adverse events or dose-limiting toxicities in the phase 1B portion of the trial.
“There is an urgent need to investigate novel immunotherapeutic agents such as cavrotolimod that can be given to enhance the clinical efficacy of immunotherapy, particularly [for] patients with refractory solid tumors,” principal investigator Adil Daud, MD, clinical professor at UCSF Helen Diller Family Comprehensive Cancer Center, said in an Exicure-issued press release.