Preclinical toxicology is when a drug’s strengths and vulnerabilities are laid bare for all to see. Imagine the invaluable insights drawn from organ-specific tests that reveal hidden adverse reactions or genotoxicity evaluations that shine a light on the risks of cellular mutations.
Such revelations can influence everything from dosing decisions to delivery methods. Yet, the road leading to this phase is not straightforward. It begs the question: When is a drug ready for preclinical toxicology testing?
The easy answer is that it depends. Determining a drug’s readiness for this pivotal phase is layered and nuanced but vital for the health and well-being of future patients.
Determining drug readiness
Multiple factors contribute to deeming a drug “ready” for toxicological assessment. Foremost among them is drug stability. This speaks to the drug’s capacity to remain efficacious and safe within its projected shelf life or duration in the body. This determines its therapeutic viability and any potential risks in long-term administration.
Parallel to stability in the hierarchy of drug readiness are dose level determinations. Scientists must determine the correct drug dosage that can be safely administered, establish a therapeutic window and identify the potential for dose-dependent adverse effects. Such pharmacodynamic and pharmacokinetic (PDPK) considerations guide subsequent trial dosing regimens and safety margins.
Selecting an appropriate in vivo test system is also pivotal. The chosen model must adequately—not necessarily identically—mirror the intended human metabolic processes, receptor targets and potential off-target effects. An incorrect model can skew results, rendering the drug’s safety data inconclusive and potentially putting patients at risk.
It’s also important not to overlook the toxicologist in determining drug readiness. After all, not all scientists are created equally. Throughout their analyses, toxicologists discern patterns, predict potential human responses and guide drug optimization processes. Their insights illuminate the drug’s readiness for further testing and uncover potential problems. Drug developers and sponsors who do not possess this expertise in-house may consider teaming up with an experienced testing partner.
It’s also worth noting that not all drugs endure preclinical toxicology testing the same way. Several factors may impact testing considerations, including:
- A drug’s intended population (e.g., pediatric, geriatric or immunocompromised patients) can influence safety parameters.
- Its administration route—whether oral, intravenous or topical—can significantly impact absorption, distribution, metabolism and excretion (ADME) profiles.
- The nature and class of the drug itself—e.g., an immunomodulator, a neuroactive compound or an anti-cancer agent—can also affect its preclinical assessment journey.
Throughout this intricate process, the goal must always be consistent: Usher drug candidates through development using a healthy level of scrutiny and an unwavering emphasis on safety and efficacy.
Potential challenges in preclinical testing
Navigating the complexities of drug development can be frustrating and resource-intensive. And while every phase of the journey has its hurdles, preclinical testing often straddles the line between scientific rigor and practical feasibility. However, three specific challenges require nuanced solutions.
- Preclinical to clinical testing: While animal models provide invaluable preliminary insights, translating these results to potential human outcomes demands caution and a comprehensive understanding of interspecies variations.
- Regulatory considerations: Preclinical testing on drug candidates is a highly regulated affair. Many guidelines outline the requirements for each stage of clinical development, depending on the nature of the drug and the disease it is intended to treat. Regulatory guidelines are written vaguely to allow for scientific interpretation and innovation, a flexibility that is especially critical for emerging technologies like gene and cell therapies. There are no step-by-step instructions for regulatory approval because it would be impossible to map out detailed instructions for every drug molecule and situation. Regardless of the path taken, scientific integrity at all levels of the process is a given.
- Timeline realities: The duration of preclinical studies can vary considerably based on the drug in question, the stage of development and the specific tests required. While some assessments may be concluded within weeks, others, especially those necessitating long-term observation, may span months or even years. A range of variables can impact these timelines and expedite or delay development.
Given these variables, proactive planning becomes a critical component in preclinical testing. A forward-thinking approach that anticipates potential challenges and unforeseen delays can keep timelines intact and test results conclusive.
How the right lab testing partner can help
The intricacies of toxicology testing are real and multifaceted. To do it correctly requires a sophisticated array of facilities, expertise and processes. When these complexities exceed internal capabilities or capacity, it’s time to find an experienced lab testing partner. The right lab partner can handle the exacting demands of preclinical toxicology testing with precision and cutting-edge technology.
But collaborating with a lab testing partner is not just a matter of convenience—it’s a strategic decision. Often, these organizations bring a wealth of expertise, a comprehensive resource infrastructure and seasoned professionals. The right testing partner can often preempt potential pitfalls, guide testing toward more accurate and conclusive results and prepare candidates for IND submission.
A final word
Preclinical toxicology testing becomes more salient as the pharmacological landscape advances and evolves. This phase establishes the safety baseline for potential therapeutics and charts their trajectory throughout drug development.
The intricacies of determining drug readiness, navigating the complexities of preclinical challenges and harnessing the prowess of testing partners highlight the importance of a meticulous approach. As we look to the future, it is not difficult to imagine a time when technological advances will complement traditional in vivo models, where real-time data analytics could offer instantaneous insights, and where collaboration between global regulators streamlines a drug’s journey from labs to markets.
Drug developers, sponsors, and testing partners, bound by the common goal of bringing safe, effective treatments to patients, must remember that their collective commitment in these initial phases can shape the health and well-being of countless patients in the future.
About the author
Tina Rogers, PhD, DABT, MBA, is a Senior Technical Director at WuXi AppTec. Dr. Rogers is well-versed in providing preclinical drug development services to biopharma, NIH and DoD. In her extensive leadership positions, including as Vice President of Preclinical Sciences at Altasciences (formerly SNBL USA), Executive Vice President and Director of Research at MPI Research (now Charles River), and Vice President of Drug Development at Southern Research Institute, she has served as an advisor and driven both growth and profitability.
Dr. Rogers holds a Ph.D. in Molecular & Cellular Biology and Pathobiology from the Medical University of South Carolina and an MBA from Auburn University. She has a broad technical background, including cell biology, immunology, toxicology, cell and gene therapy, sepsis, inflammation, BL-3 and select agents, flow cytometry, and predictive/in vitro toxicology. Dr. Rogers shares her extensive experience serving as a board member for several biotech, academic, and not-for-profit institutions and as a Diplomate of the American Board of Toxicology (DABT).
Filed Under: Biologics, clinical trials, Drug Discovery, Regulatory affairs