The U.S. Food and Drug Administration (FDA) recently issued draft guidance on obtaining "Qualified Infectious Disease Product" (QIDP) designation for antibacterial and antifungal drug candidates intended to treat serious or life-threatening infections.¹ QIDP designation is important. FDA approval of a QIDP-designated drug candidate can result in other awarded exclusivities (e.g., three-year new dosage form, five-year new chemical entity, and orphan) each being extended by an additional five years (GAIN Act exclusivity).

There is a critical need for new antibiotic and antifungal drugs. QIDP designation and the GAIN Act exclusivity awarded upon FDA approval are designed to incentivize the development of these important drug classes. Because QIDP designation can result in a significantly increased period of market exclusivity, it is important that antibiotic and antifungal drug makers are equipped with a clear understanding of how to apply for and obtain QIDP designation, and how to obtain and take advantage of other expediting mechanisms that can accompany QIDP designation (e.g., fast-track and priority review).

The 2018 Guidance

The draft guidance clarifies implementation of the GAIN Act using a question-and-answer format. The draft guidance focuses on:

• Eligibility for, and limitations of, QIDP designation
• When the QIDP designation request should be submitted to the FDA
• Information that should be contained in a QIDP designation request
• Expedited mechanisms associated with QIDP designation

In this WSGR Alert, we highlight important aspects of the FDA's draft guidance.

QIDP Designation Eligibility

Intended to Treat Serious or Life Threatening Infection(s)

To gain QIDP designation, drug candidates must be intended to treat serious or life-threatening infection(s). In addition to therapeutic molecules, QIDP designation may also be available for drug candidates intended to diagnose or prevent serious or life threatening infection(s).²

A key takeaway is that the QIDP designation statutory standard is distinct from the FDA's list of qualifying pathogens. Thus, a drug candidate that is not intended for treating a qualifying pathogen may still be eligible for QIDP designation. On the other hand, a drug candidate that is intended for treating a qualifying pathogen is not automatically eligible for QIDP designation; the drug candidate also must be intended for treating a serious or life-threatening infection.³

Biologics and Medical Devices Are Not Eligible

QIDP designation is limited to human drugs, or combination products, whose applications are submitted under section 505(b) of the Federal Food, Drug, and Cosmetic Act. Therefore, QIDP designation is not available for biologics and medical devices.⁴

Limitations of a QIDP Designation

Another important consideration is that QIDP designation is limited to a specific drug product, from a specific sponsor, for a specific use. The QIDP designation, therefore, does not include an industry-wide special status for the drug substance and also does not extend to additional indications.⁵

When to Request QIDP Designation

QIDP designation may be requested any time prior to submission of a new drug application (NDA). The designation request should be submitted either to an investigational new drug application (IND) or in pre-IND correspondence. It is possible to submit a single request for multiple indications. When making a multiple indication submission, each indication should be clearly identified.

Contents of a QIDP Designation Request

The QIDP designation request should contain information that supports the activity of the drug candidate as an antibacterial or antifungal drug. This can include:

1. in vitro data;
2. data on the mechanism of action of the drug candidate;
3. data from animal models of infection; and
4. human clinical trial data.⁶

Note: Items (i)-(iv) above track with the developmental progression of a clinical candidate.

Additionally, the designation request should contain the specific serious or life-threatening indication(s) for which the sponsor intends to develop the drug; and the rationale or suitability for developing the drug for the proposed serious or life-threatening indication(s).⁷

Finally, the designation request may contain (but is not required to include) information to demonstrate that the drug candidate has the capacity to treat a serious or life-threatening infection caused by: resistant pathogens or qualifying pathogens (as found in 37 C.F.R. Section 317.2).⁸

The FDA's stated goal is to respond to a QIDP designation request within 60 calendar days from request submission.⁹

Expediting Mechanisms

Although a QIDP-designated drug candidate is eligible for fast-track designation, fast-track designation must be specifically requested. The request for fast-track designation can be included in the QIDP designation request. Additionally, the FDA will give priority review to the first application submitted for a specific drug product and indication for which the QIDP designation was granted.¹⁰

Conclusion

It is important for companies developing antibacterial and antifungal drugs to be familiar with the FDA's draft guidance and the requirements for gaining QIDP designation.