anidulafungin (Eraxis ®)

Mechanism of action
Anidulafungin is a semi-synthetic echinocandin with antifungal activity. Anidulafungin inhibits glucan synthase, an enzyme present in fungal, but not mammalian cells. This results in inhibition of the formation of 1,3-ß-D-glucan, an essential component of the fungal cell wall.

Activity in vitro
Anidulafungin is active in vitro against:
Candida albicans,
C. glabrata,
C. parapsilosis, and
C. tropicalis
(see INDICATIONS AND USAGE).

MICs were determined according to the Clinical and Laboratory Standards Institute (CLSI) approved standard reference method M27 for susceptibility testing of yeasts. However, no correlation between in vitro activity (MIC) as determined by this method and clinical outcome has been established.

Activity in vivo
Parenterally administered anidulafungin was effective against Candida albicans in immunocompetent and immunosuppressed mice and rabbits with disseminated infection as measured by prolonged survival and reduction in mycological burden. Anidulafungin also reduced the mycological burden of fluconazole-resistant C. albicans in an oropharyngeal/esophageal infection model in immunosuppressed rabbits.

Drug Resistance
Emergence of resistance to anidulafungin has not been studied.

Anidulafungin was active against Candida albicans resistant to fluconazole. Cross resistance with other echinocandins has not been studied.

INDICATIONS AND USAGE
ERAXIS is indicated for use in the treatment of the following fungal infections:

Candidemia and other forms of Candida infections (intra-abdominal abscess, and peritonitis).

ERAXIS has not been studied in endocarditis, osteomyelitis, and meningitis due to Candida, and has not been studied in sufficient numbers of neutropenic patients to determine efficacy in this group.

Esophageal candidiasis (see package insert for CLINICAL STUDIES (Table 7) for higher relapse rates off ERAXIS therapy).

Specimens for fungal culture and other relevant laboratory studies (including histopathology) should be obtained prior to therapy to isolate and identify causative organism(s). Therapy may be instituted before the results of the cultures and other laboratory studies are known. However, once these results become available, antifungal therapy should be adjusted accordingly.

Candidemia and other Candida infections (intra-abdominal abscess, and peritonitis)
The recommended dose is a single 200 mg loading dose of ERAXIS on Day 1, followed by 100 mg daily dose thereafter. Duration of treatment should be based on the patient's clinical response. In general, antifungal therapy should continue for at least 14 days after the last positive culture.

Esophageal candidiasis
The recommended dose is a single 100 mg loading dose of ERAXIS on Day 1, followed by 50 mg daily dose thereafter. Patients should be treated for a minimum of 14 days and for at least 7 days following resolution of symptoms. Duration of treatment should be based on the patient's clinical response. Because of the risk of relapse of esophageal candidiasis in patients with HIV infections, suppressive antifungal therapy may be considered after a course of treatment.

No dosing adjustments are required for patients with any degree of renal or hepatic insufficiency, patients using concomitant medications or those in other special populations