FDA Approves Cidara’s Antifungal Therapy

Amidst a growing problem of Candida auris fungal infections spreading at healthcare facilities, last month the FDA approved the first new echinocandin treatment for candidemia and invasive candidiasis in over a decade.

REZZAYO (rezafungin for injection) is a novel once-weekly echinocandin treatment developed by San Diego-based Cidara Therapeutics, Inc. and exclusively commercialized in the U.S. by Melinta Therapeutics, LLC.

“The FDA approval of REZZAYO represents a significant milestone for Cidara, and for patients confronted with difficult-to-treat and often deadly candidemia and invasive candidiasis,” said Jeffrey Stein, Ph.D., president and CEO of Cidara. “I am extremely proud of all of the Cidara employees who collectively advanced REZZAYO from preclinical development to NDA approval and am grateful to the many patients and healthcare teams who have participated in the clinical studies.”

New Method for Treating Fungal Infection

REZZAYO is differentiated from current standard care for fungal infections because it is administered through weekly IV dosing as opposed to daily infusions. Additionally, its pharmacokinetics allow for front-loaded dosing that provides faster time to fungal clearance in the clinic, less potential for resistance development due to high initial drug exposure, and less potential for underdosing.

“The FDA approval of REZZAYO is tremendous news for those of us who have been hoping for a new option to treat our patients with these deadly fungal infections,” said George Thompson, M.D., principal investigator in the ReSTORE clinical trial of rezagungin and professor of clinical medicine at the University of California, Davis, School of Medicine. “Based on the totality of clinical data generated, REZZAYO has the potential to simplify the management of invasive candidiasis and enhance the continuity of echinocandin care.”

Fungal infections have become a growing concern in healthcare. Last month, the Centers for Disease Control and Prevention released data that Candida auris (C. auris), an emerging fungus considered an urgent antimicrobial resistance (AR) threat, spread at an alarming rate in U.S. healthcare facilities in 2020-21.

The FDA approval of REZZAYO was based on the demonstrated safety and effectiveness of rezafungin for the treatment of candidemia (Candida infection of the blood) and invasive candidiasis (Candida infection of the tissues/organs). Both conditions can be caused by several Candida species, including C. auris. Additionally, in preclinical studies, rezafungin showed improved activity to manage resistant pathogens, including C. auris and other Candida strains such as C. glabrata.

Lucrative Deal

As part of the licensing deal with Melinta, Cidara will receive a $20 million regulatory milestone payment, adding to the $30 million it received when the deal was inked last summer.

“Rezafungin is the first new drug in this indication in over a decade and our U.S. commercial partner, Melinta, is well-positioned to bring rezafungin to the U.S. market,” Stein said.

Under the terms of the agreement with Melinta, Cidara is eligible to receive up to $40  million in additional regulatory milestones, and up to $370  million in commercial milestones, plus tiered royalties in the low double digits to mid-teens on U.S. net sales of rezafungin.

“We are thrilled that the FDA has approved REZZAYO and are firmly committed to offering this innovative therapy to address unmet medical needs and simplify the treatment for patients suffering from invasive Candida infections,” said Christine Ann Miller, president and CEO of Melinta Therapeutics. “We intend to leverage our expansive commercial infrastructure and experience launching anti-infective drugs into acute care settings.  We are working closely with Cidara and anticipate bringing REZZAYO, a differentiated once-weekly treatment to patients, this summer.”

Although rezafungin is currently only approved in the U.S., the European Medicines Agency (EMA) accepted the marketing authorization application (MAA) for rezafungin in August 2022 and it is currently under review.  The marketing authorization application (MAA) has also been submitted in other regions.

In addition to its commercialization deal with Melinta, Cidara has partnered with U.K.-based Mundipharma for commercialization of rezafungin in all other geographies outside the U.S., with the exception of Japan, which Cidara has retained the rights to.

Cidara Therapeutics, Inc.

Founded: 2012
CEO: Jeffrey Stein, Ph.D.
Headquarters: San Diego
Business: Developer of long-acting therapeutics designed to improve the standard of care for patients facing serious diseases.
Stock: CDTX (Nasdaq)
Revenue: $64.3 million (FY2022)
Employees: 73
Website: www.cidara.com
Notable: In 2021, Cidara was named a San Diego Metro Area Top Workplace for the fifth consecutive year by the  San Diego Union-Tribune.