MK-3118 is an orally active inhibitor of fungal β-(1,3)-glucan synthase patented by Merck Sharp & Dohme Corp for the treatment of fungal infections. MK-3118 demonstrated enhanced efficacy for most C. albicans and C. glabrata ER isolates relative to caspofungin. MK-3118 showed no or poor activity against Mucoromycotina and Fusarium spp. However, MK-3118 was highly active against Paecilomyces variotii and was the only compound displaying some activity against notoriously pan-resistant Scedosporium prolificans.

Caspofungin is an echinocandin antifungal drug, which is approved and is sold under the brand worldwide name cancidas. Caspofungin inhibits the synthesis of beta (1,3)-D-glucan, an essential component of the cell wall of susceptible Aspergillus species and Candida species. Beta (1,3)-D-glucan is not present in mammalian cells. Cancidas is indicated for the treatment of candidemia and the following candida infections: intra-abdominal abscesses, peritonitis, and pleural space infections in adult and pediatric patients. Also is indicated for the treatment of esophageal candidiasis in adult and pediatric patients and for the treatment of invasive aspergillosis in adult and pediatric patients, but has not been studied as initial therapy for invasive aspergillosis.