Fungal infections pose significant medical challenges in both hospital and outpatient settings. While fungi are ubiquitous in our environment, they are usually harmless for people with a normal immune system. Most fungal infections are topical and local in nature, occurring on the skin, in the vaginal tract or in other parts of the body.
However, if fungi access and proliferate in the bloodstream, these infections become systemic and potentially life threatening. Systemic fungal infections typically afflict patients whose immune systems have been compromised, such as patients undergoing organ or bone marrow transplantation, chemotherapy or patients with AIDS.
We estimate that the annual worldwide sales of prescription systemic antifungals are approximately $4 billion. This includes therapies used as prophylaxis (preventive) in the outpatient setting, therapies used for the treatment of hospitalized patients and therapies used for the treatment of patients who are being discharged from the hospital.
The majority of hospital infections are caused by two fungi, Candida and Aspergillus. These fungi are responsible for over 90% of the approximately 97,000 deaths that we estimate are associated annually in the United States with fungal infections.
Estimated U.S. Deaths in Patients with Hospital Treated Fungal Infections
Estimated U.S. Days of Therapy of Antifungals in Prophylaxis, Hospital and Outpatient (Discharge) Settings
*High-risk populations: Acute leukemia, Allo HSCT, SOT
Lack of Innovation Prompts Action by Regulators
Physicians’ options for the treatment of fungal infections are limited by a lack of innovative therapies. The last new class of antifungals introduced into the market was launched in 2001. Several factors have contributed to the low rate of antifungal and antibiotic drug development, including a previously challenging regulatory environment that necessitated large and costly clinical trials. As a result, the number of anti-infectives in development has decreased, while anti-microbial resistance has increased due to overuse of existing agents.
In recognition of this trend, recent regulatory changes, including priority review and regulatory guidance enabling smaller clinical trials, have led to renewed interest in the pharmaceutical industry in anti-infective development. For example, the Food and Drug Administration Safety and Innovation Act became law in July 2012 and included the Generating Antibiotic Incentives Now Act, or the GAIN Act.
The GAIN Act is intended to provide incentives, including access to expedited FDA review for approval, fast track designation and five years of potential market exclusivity extension (beyond any period of exclusivity to which it would have otherwise been entitled) for the development of new, qualified infectious disease products, or QIDP, including antibacterial or antifungal drugs intended to treat serious or life-threatening infections that are resistant to treatment, or that treat qualifying resistant pathogens identified by the FDA.
Additional legislation (the ADAPT Act and DISARM Act) is under review.