Emerging Viral Infections - Information for Industry

In addition to diseases such as HIV/AIDS, herpesvirus infections, and viral hepatitis, the Division of Antiviral Products reviews submissions and applications for antiviral products (including antiviral drugs and certain types of biologic products) directed against a range of infections that have recently emerged or re-emerged, or could emerge under certain conditions of public health crisis, as major causes of human illness. This category of emerging viral infections includes (but is not limited to) the following:

• Infections that may spread widely due to genetic changes in existing viral pathogens (such as novel strains of influenza);
• Infections appearing in new settings due to movement of human populations or of animal reservoirs  (such as West Nile virus or monkeypox);
• Infections newly recognized as causes of human disease (such as SARS or hantavirus pulmonary syndrome);
• Infections that are rare or nonexistent under normal circumstances but that could be sources of significant concern in the context of potential bioterrorism/biowarfare threats (such as smallpox, serious vaccinia infections complicating smallpox vaccination, or certain viral hemorrhagic fevers).

Approaches to drug development for emerging viral infections

Development of drugs for emerging viral infections poses distinctive challenges because many of these illnesses are rare but may be life-threatening, and have the potential to change rapidly in incidence and/or virulence, such that a serious public health threat could arise with little advance opportunity for study. Thus, although developing treatment and control measures is a high priority, the traditional sequence of nonclinical and clinical studies may be very difficult to implement. In order to facilitate progress without compromising scientific standards, careful attention to the following possible approaches may be desirable. Prospective sponsors should discuss these with the review division:

• Consideration of potential applicability to emerging infections during development of antivirals for other purposes;

• Assembly and analysis of treatment experience for related products and diseases that may have indirect relevance to the product and disease of interest;

• Prospective design of nonclinical studies (including shared discussion of planned animal studies across all review disciplines) to provide as much supplemental information as possible in support of potentially limited clinical data;

• Prospective design of clinical trials to maximize the amount of useful information that may be gained from sparse experience, and to address both the importance of adequately controlled and monitored trials and the constraints of study conduct under emergency conditions;

• Regulatory mechanisms for facilitation of timely interactions.

Sponsors seeking to develop antiviral drugs for emerging infections are urged to communicate with the Division as early in the development process as possible.  Typically the Pre-IND consultation program  will provide an appropriate mechanism for such early consultations.  For some drug development programs for emerging infections, repeated Pre-IND interactions may be desirable.