Can Ibrexafungerp Treat Candida Auris?

In a small study, the newly FDA approved antifungal demonstrated “clinical activity” against the emerging pathogen.

The US Centers for Disease Control and Prevention (CDC) has declared that Candida auris (C. auris) is an emerging, multidrug-resistant fungus, which has raised concerns within the healthcare community. The CDC also reported that from May 1, 2020 to April 30, 2021, there were 2193 confirmed and probable cases of C. auris in the United States.

And in recent days reports of outbreaks occurred in both a nursing home in Washington, DC and in 2 Dallas-area hospitals.

According to the reports, some of these patients infected with C. auris did not show any clinical improvement after being treated with all 3 major classes of the antifungals. In fact, in 5 patients who were fully resistant to treatment, 3 of them died.

While C. auris does not appear to have a high incidence rate, the infection presents some serious challenges to clinicians. It is especially troublesome as the CDC has outlined 3 main concerns about it, including it is often multidrug-resistant; it being a newer, emerging fungus, it can be challenging for labs to diagnose with standard laboratory methods, which can lead to misidentification and in turn lead to the incorrect treatment and management; and lastly, it can lead to outbreaks in healthcare facilities.

In the most recent outbreaks, a cluster of 101 cases were detected in the Washington, DC, nursing home and a cluster of 22 cases were determined in the 2 Dallas areas hospitals.

And this healthcare-associated infection (HAI) can contaminate the patient care environment and remain on surfaces for weeks to months.

All these factors are concerning to the healthcare community and combined with a mature antifungal market, which echoes the antibiotic market, not many treatment options are on the horizon.

One antifungal, ibrexafungerp, was recently approved by the Food and Drug Administration (FDA) for treatment of vulvovaginal candidiasis (VVC), and is also being studied for C. auris treatment. The therapy, which represents the first approved drug in a novel antifungal class in more than 20 years, was approved based on positive results from 2 phase 3 studies in which oral ibrexafungerp demonstrated efficacy and a favorable tolerability profile in women with VVC.

The therapy was developed by Jersey City, New Jersey-based biotechnology company, Scynexis. The company has also been studying ibrexafungerp in its CARES study in hospitalized patients with C. auris.

In an interim analysis in a small sample study from its CARES study, the antifungal showed “strong clinical activity of oral ibrexafungerp in patients with Candida auris.”

Participants in the CARES study received a loading dose of oral ibrexafungerp 750 mg BID during the first 2 days, and then subsequent oral ibrexafungerp 750 mg QD for up to 90 days and are followed for 6 weeks after end of therapy. Scynexis said an independent Data Review Committee provided an assessment of treatment response for 10 patients who completed therapy by October 2020.

“Our product, given orally, has been able to clear the infection in 8 of the first 10 patients we treated,” Scynexis CEO Marco Taglietti, MD, told Contagion in an interview. “It is not unexpected because the mechanism of action of this drug being a glucan synthase inhibitor is really the type of mechanism that we know is exquisitely effective against Candida in general and in Candida auris.”

Additionally, the company reports that, “on an aggregate basis, oral ibrexafungerp showed clinical benefits in 86.5% of patients (64 out 74), with 46 patients achieving a complete or partial response and 18 patients achieving a stable disease response,” the company said in a statement. “Of the 74 treated patients, only five did not respond to ibrexafungerp treatment, one patient died of an underlying condition unrelated to the treatment and four patients were considered indeterminate.”

Taglietti said the CARES study was designed to assess if ibrexafungerp is potentially eligible to qualify for the FDA’s Limited Population Pathway for Antibacterial and Antifungal Drugs (LPAD pathway) for C. auris treatment. “Our plan is to continue to collect the data, to continue to have discussions with the FDA, and what we expect is to provide some guidance in the future.”

While larger studies are needed to see if ibrexafungerp can continue to have therapeutic benefits against C. auris, the emergence of this pathogen might get more public health officials, hospital administrators, and pharmaceutical companies thinking about antifungals and their importance in healthcare.