New treatment for invasive fungal infection candidiasis approved by FDA

The U.S. Food and Drug Administration (FDA) has approved rezafungin for injection, (REZZAYO^TM), a treatment for patients with candidemia and invasive candidiasis.

The new treatment is the first approved for the invasive fungal infection in over a decade. It is a novel antifungal therapy given once a week intravenously.

“Based on the totality of clinical data generated, rezafungin for injection has the potential to simplify the management of invasive candidiasis and enhance the continuity of antifungal care,” said George Thompson, professor of infectious diseases at UC Davis Health.

ReSTORE clinical trial

The FDA approval of rezafungin for injection was based on clinical data from a Phase 3 trial called ReSTORE, in which Thompson served as the principal investigator.

The double-blind trial was done at 66 tertiary care centers in 15 countries. Tertiary care centers are hospitals that provide high levels of specialized care.

Adults 18 years of age or older with invasive candidiasis were randomly assigned to receive one of two treatments. About half got rezafungin for injection once a week (400 mg in week 1, followed by 200 mg weekly, for a total of two to four doses). The other half received intravenous caspofungin, the current standard of care that is given once daily (70 mg on day 1, followed by 50 mg daily) for no more than four weeks.

In total, 199 patients were randomly assigned to the rezafungin for injection group (100 patients) and the caspofungin group (99 patients). Results showed that:

• 55 of 93 patients in the rezafungin for injection group and 57 of 94 patients in the caspofungin group were cured at day 14.
• 22 (24%) of 93 patients in the rezafungin for injection group and 20 (21%) of 94 patients in the caspofungin group passed away or had an unknown survival status at day 30.
• In the safety analysis, 89 of 98 patients in the rezafungin for injection group and 83 of 98 patients in the caspofungin group had at least one treatment-emergent adverse event. These include medical conditions that were not present prior to treatment, or those that worsened after treatment.
• The most common treatment-emergent adverse events in at least 5% of patients in either group were fevers, low potassium levels, pneumonia, septic shock, and anemia.
• 55 patients in the rezafungin for injection group and 52 in the caspofungin group had serious adverse events.

“When analyzing the data, we saw when given once weekly to patients, rezafungin for injection showed similar results to caspofungin,” Thompson explained.

What is invasive candidiasis?

Invasive candidiasis is a serious fungal infection caused by a yeast of the Candida species (candidemia). It occurs most frequently in patients with compromised immune systems.

According to the Centers for Disease Control and Prevention, candidemia is one of the most common causes of bloodstream infections in hospitalized patients in the United States. It often results in long hospital stays and is also responsible for high medical costs. Despite therapy, the overall mortality rate of invasive candidiasis remains over 30%.

Current treatment options are limited to only three antifungal classes, with only one class available in oral form. Most therapies have become increasingly ineffective due to a rise in drug-resistant strains.