It is currently in phase 3 of clinical development. Isavuconazole demonstrated in-vitro and in-vivo coverage of a broad range of yeasts (such as Candida species) and molds (such as Aspergillus species) as well as activity in in-vitro studies and in animal models against emerging and often fatal molds including those that cause zygomycosis. Isavuconazole received U.S. FDA fast-track status. In addition the FDA granted isavuconazole orphan drug designations for the treatment of invasive aspergillosis and zygomycosis. Isavuconazole is being co-developed with Astellas Pharma Inc.
Ongoing phase 3 program
The phase 3 program with isavuconazole includes three studies, SECURE, VITAL and ACTIVE. The SECURE study is a global double-blind randomized phase 3 study, designed to evaluate the safety and efficacy of once-daily isavuconazole versus twice-daily voriconazole in the primary treatment of invasive fungal disease caused by Aspergillus species or other filamentous fungi. The VITAL study is an open-label phase 3 study of isavuconazole in the treatment of aspergillosis patients with pre-existing renal impairment or patients with invasive fungal disease caused by emerging and often fatal molds, yeasts or dimorphic fungi. The ACTIVE phase 3 study is evaluating the safety and efficacy of intravenously (i.v.) and orally administered isavuconazole versus i.v. caspofungin followed by oral voriconazole in the treatment of invasive Candida infections. Enrollment in the open-label phase 3 isavuconazole VITAL study including patients with invasive fungal disease caused by mucormycetes and other emerging fungal pathogens and patients with aspergillosis and pre-existing renal impairment has been completed. In September 2013, positive topline results for the SECURE phase 3 study were reported.
The need for new antifungal therapies
The expansion of the immunocompromised patient population including cancer patients with chemotherapy-induced neutropenia and transplant recipients receiving immunosuppressive therapy has led to an increased incidence of invasive fungal infections. Invasive aspergillosis is estimated to occur in 5-13% of recipients of bone marrow transplants, 5-25% of patients who have received heart or lung transplants, and 10-20% of patients who are receiving intensive chemotherapy for leukemia.1 Mortality rates for transplant patients with invasive aspergillosis have been reported to be between 34% and 58%.2 There is a high medical need to address the limitations of current therapies, most importantly the gaps in the antifungal spectrum, unwanted side effects, limited dosing flexibility as well as the development of resistance.