Some innovative drugs are receiving an additional five years of marketing exclusivity on top of their other exclusivities because they qualify under the Generating Antibiotic Incentives Now (GAIN) title of the Food and Drug Administration Safety and Innovation Act as a qualified infectious disease product (QIDP). GAIN came into play in 2012, and companies are already taking advantage of the benefits it provides. QIDPs may receive priority review and fast-track status at FDA. They also may receive five additional years of regulatory exclusivity. This means, for example, that if the QIDP also qualifies as a new chemical entity (NCE), it may enjoy 10 years of regulatory exclusivity instead of five, and generic-drug companies may need to wait nine years to initiate Hatch-Waxman litigation instead of four. By considering the requirements for QIDP designation and how other companies are using it for their products, pharmaceutical companies can gain insight into whether their own innovative products qualify for GAIN’s benefits.

Requirements for QIDP Designation

Antimicrobial drug resistance has received increasing attention in recent years as a serious public health concern, with an estimated two million people in the United States infected by antibiotic-resistant bacteria each year.1 GAIN was enacted in 2012 to encourage the development of next-generation antibacterial and antifungal drugs by providing various incentives.2 To qualify for the incentives, a drug must be designated by FDA as a QIDP, defined as “an antibacterial or antifungal drug for human use intended to treat serious or life-threatening infections, including those caused by—an antibacterial or antifungal resistant pathogen, including novel or emerging infectious pathogens; or qualifying pathogens listed by the [FDA]”.3

FDA, in consultation with scientific and medical experts, provided its first list of qualifying pathogens in 2014.4 The list includes the 21 pathogens identified in Table I, and FDA will review and update the list at least every five years.3, 5

FDA places pathogens on the list based on considerations of "the impact on the public health due to drug-resistant organisms in humans," "the rate of growth of drug-resistant organisms in humans," "the increase in resistance rates in humans," and “the morbidity and mortality in humans".3 For the first consideration, FDA will assess evidence such as the transmissibility of the pathogen and the availability of effective therapies for treatment of infections caused by the pathogen. For the second and third considerations, FDA will assess evidence such as the proportion of patients whose illness is caused by a drug-resistant isolate of a pathogen, the number of resistant clinical isolates of a particular pathogen, and the ease and frequency with which a proposed pathogen can transfer and receive resistance-conferring elements. And for the fourth consideration, FDA will assess evidence such as a meaningful increase in morbidity and mortality rates when infection with a drug-resistant strain of a pathogen is compared to infection with a more drug-susceptible strain of that pathogen. If the totality of the evidence demonstrates that the pathogen has the potential to pose a serious threat to public health, FDA will identify it as a qualifying pathogen.4 

Treatment of an infection caused by a qualifying pathogen is neither sufficient nor required for QIDP designation. First, a drug does not necessarily receive QIDP designation just because it is intended to treat an infection caused by a qualifying pathogen. This stems from differences in standards, with qualifying pathogens having "the potential to pose a serious threat to public health," and QIDPs being "intended to treat serious or life-threatening infections." Second, a drug may receive QIDP designation even if it does not treat an infection caused by a pathogen on the list.4 For example, a drug may receive QIDP designation if it is an antibacterial drug for human use intended to treat a serious infection caused by an antibacterial resistant pathogen that is not on the list. 

QIDPs must be human drugs whose applications are submitted pursuant to § 505(b) of the Federal Food, Drug, and Cosmetic Act (FDCA), 21 U.S.C. § 355(b). Combination products whose applications are submitted under that same section may also qualify for QIDP designation. Biologic products, however, that are approved for marketing pursuant to § 351 of the Public Health Service Act, 42 U.S.C. § 262, cannot be designated as QIDPs. Similarly, devices that are cleared pursuant to § 510 of the FDCA, 21 U.S.C. § 360, or approved pursuant to § 515 of the FDCA, 21 U.S.C. § 360e, cannot be designated as QIDPs.6

QIDPs can be novel drugs or those that contain approved active moieties. Many investigational QIDPs are approved drugs being developed with modifications, such as a new dosage form or indication.7