FDA Accepts Astellas' NDA For Isavuconazole For Invasive Aspergillosis and Invasive Mucormycosis

Astellas announced in a press release that the Food and Drug Administration (FDA) has accepted its New Drug Application (NDA) for isavuconazole. The intravenous and oral broad-spectrum antifungal is for the treatment of invasive aspergillosis and invasive mucormycosis. The FDA is required to act on the application by March 8, 2015. The FDA has already granted isavuconazole Qualified Infectious Disease Product (QIDP) status and Orphan Drug status for invasive aspergillosis and invasive mucormycosis, both of which are life-threatening fungal infections.

Basilea Pharmaceutica is co-developing the agent with Astellas and will receive a milestone payment from Astellas of CHF 12 million ($13 million) due to the FDA’s application acceptance. Ronald Scott, Basilea's CEO, stated in a press release, "We are pleased with the FDA acceptance of the NDA filing shortly after our European MAA was accepted. Isavuconazole has the potential to be a valuable new therapeutic option for patients suffering from invasive fungal infections."

Isavuconazole

Isavuconazole is the active moiety of the prodrug isavuconazonium sulfate. The once-daily antifungal demonstrates action against a wide variety of fungal infections, such as the Candida species, and molds such as the Aspergillus species. The drug also serves as protection against the fatal molds that cause mucormycosis. In a Phase III study of invasive aspergillosis, the agent proved non-inferior to voriconazole, a triazole antifungal medication that slows the growth of the fungi that causes infection. Adverse events were lower for isavuconazole than for voriconazole.

Basilea states that its Phase III clinical program for isavuconazole is ongoing and includes the SECURE, VITAL, and ACTIVE studies. SECURE is a global study evaluating the safety and efficacy of once-daily isavuconazole versus twice-daily voriconazole. VITAL is studying aspergillosis patients with pre-existing renal impairment or patients with invasive fungal disease caused by fatal molds, yeasts, or dimorphic fungi. ACTIVE is evaluating intravenous and oral isavuconazole vs. caspofungin, followed by oral voriconazole in the treatment of invasive Candida infections.

Unmet Need for Antifungal Therapies

Invasive aspergillosis and invasive mucormycosis are often found in immunocompromised patients, which include cancer patients and transplant recipients. The mortality rates for these patient populations are as high as 58 percent, according to Basilea. An unmet need for new treatments exists due to resistance to current therapies, side effects, and limited dosing flexibility.