Introduction
Drug discovery and development is a complicated journey, and many factors impact the likelihood of delivering a new medicine. Small molecule direct-acting antivirals (DAAs) are a crucial component of the approaches needed to prevent and treat viral infections on a global scale. One cannot understate the importance of antiviral discovery and development programs to address current and future risks to patient health, including for infected and uninfected people.
The INTREPID Alliance seeks to catalyze the antiviral R&D ecosystem by creating and highlighting resources that can help drug discoverers and developers achieve this goal. In this section of the INTREPID Alliance Antiviral Toolbox, we highlight resources that may help inform the strategic R&D approaches to identify, characterize, and progress novel antivirals.
Click on the tools below to access these resources.
INTREPID Alliance Target Compound Profile
A target compound profile (TCP) helps inform early-stage antiviral R&D activity.
Target Product Profiles
A target product profile (TPP) helps inform the later stages of antiviral R&D activity and is tied more specifically to a particular virus or viral disease.
In Vitro Antiviral Assays
Choosing a relevant virus and cell-based assay is an important part of early antiviral R&D.
Preclinical In Vivo Antiviral Models
Preclinical in vivo models of antiviral efficacy can support compound progression and may inform initial designs of clinical studies in humans.
INTREPID Alliance Target Compound Profile
A Target Compound Profile (TCP) describes the characteristics of an antiviral that are generally associated with physical, chemical, and biological properties that increase the likelihood of success.
Reference: Demarest JF, Draghia-Akli R, Cihlar T, Bradley K, Young JAT, Chandra R, Vaidyanathan S, Chu-Moyer M, Lynch CL, Campbell A, Saikatendu KS, Bilello JP, Murata Y, van Loock M, Hurt AC, Tellinghuisen T, Ruggiero L, Mackman R, Hill NM, Pottage JC Jr; INTREPID Alliance. Antiviral target compound profile for pandemic preparedness. Nat Rev Drug Discov. 2025 Feb;24(2):151-152.
Target Product Profiles
Target Product Profiles (TPPs) are generally more specific to a particular virus/viral disease than a TCP and focus more on characteristics associated with the later stages of clinical development. A TPP describes the essential characteristics of the medicinal product that align with unmet medical needs as well as other factors, such as dosing, drug-drug-interactions, safety, storage and distribution, to name a few.
Reference: U.S. National Institutes of Health. National Institute of Allergy and Infectious Disease. Target Product Profiles for Antivirals. Accessed 15 October 2025. https://www.niaid.nih.gov/research/target-product-profiles-antivirals.
Reference: World Health Organization. Target Product Profile Directory. Accessed 15 October 2025. https://www.who.int/our-work/science-division/research-for-health/target-product-profile-directory.
Reference: Drugs for Neglected Diseases initiative (DNDi). Research and Development: Target Product Profiles. Accessed 15 October 2025. https://dndi.org/research-and-development/target-product-profiles/.
In Vitro Antiviral Assays
For a given virus, there may be multiple replication-competent viruses that are capable of multiple rounds of infection in vitro (e.g., clinical or lab-adapted virus isolates). In addition, other reagents may be available to focus analyses on a particular part of a virus life cycle (e.g., pseudoviruses, replicons). Furthermore, depending on the particular virus, the number of primary cell types or transformed cell lines that support replication may vary. For antiviral drug discovery activities such as compound library screening, lead optimization, characterization of resistance, or other antiviral-specific measures, the drug discoverer may rely on one or more virus(es)/cell(s) pairings that best fit the need. Using viruses and cells best suited for these early antiviral R&D activities can reduce unnecessary and/or inaccurate results that may adversely affect the drug discovery effort.
A first iteration of such a resource focused on in vitro antiviral assays for flaviviruses that could help drug discoverers in their efforts is forthcoming.
Preclinical In Vivo Antiviral Models
It is well accepted that preclinical in vivo models may not always translate to efficacy in the clinic; this is true as well for antivirals. Having said that, the judicious use of preclinical models may inform progression of an antiviral. For example, the ability to inform a minimal target exposure required for efficacy or provide a means of evaluating the activity and/or mechanism of an antiviral against a virus where studies in patients are not feasible. The availability of a catalog of viruses, animal species, and experimental conditions most relevant for preclinical evaluation of an antiviral may help the translational scientist’s experimental design to provide the most value for the program.
A first iteration of such a resource focused on preclinical in vivo antiviral models for flaviviruses that could help drug discoverers in their efforts is forthcoming.