New approach methodologies (NAMs) originated in chemical hazard assessment, where two forces operate together: the scale of characterizing many substances, and a long-standing ethical and legal commitment to replacing animal testing. Drug development is weighted differently. It is a translational and decision problem applied to small sets of compounds at pharmacologically active exposures. As NAMs capabilities have expanded, the two domains have been conflated, and framing NAMs against animal studies as a binary choice risks undermining both. The so-called translatability crisis is not a single problem with a single solution. Clinical attrition reflects gaps in mechanistic understanding, exposure-irrelevant study designs, underpowered analyses, and survivorship bias that obscures the screening value of nonclinical studies. Addressing these challenges requires an integrated strategy in which the choice of platform, the design of endpoints, and the rigor of validation are governed by a clearly defined context of use. A biologically relevant model is defined not by its type but by its fitness for the purpose it serves. We argue for a patient-centered nonclinical paradigm that combines animal and non-animal approaches, aligned with recent FDA, NIH, and EMA direction, and note that both domains converge on the same non-dogmatic conclusion.
Core battery cardiovascular (CV) parameters [e.g., arterial blood pressure (BP), electrocardiogram (ECG), heart rate (HR)] are recorded in non-rodent safety pharmacology and toxicology studies. Data is used to support drug development in accordance with regulatory guidelines (e.g., ICH S7A. S7B S6, S9 and M3(R2)). However, the quality of measurements varies based on the methods used, ranging from restraint (unacclimated) to telemetry (implanted or jacketed)-based recordings. This analysis reviewed and compared current practice regarding methodological approaches applied to the acquisition of CV data in repeat-dose non-rodent toxicology studies. The data was sourced from 7 Sponsors, 2 major CROs and FDA regulatory drug approvals. Studies evaluated data acquired from dogs or non-human primates (NHP) with study durations up to 52 weeks. A literature-based search and proprietary published examples were used to establish baseline CV values and to ascertain the ability of the different methodologies used to detect drug-induced CV effects. The literature search provided evidence that baseline CV (BP and HR) values are consistently higher in restrained versus non-invasive telemetry methods. Moxifloxacin and proprietary drugs showed that hERG-mediated QTc prolongation was detected in the clinic and in NHP or dog studies using telemetry methods but not in restrained surface‑lead snapshot methods. Data showed that the ECG is collected in most repeat-dose toxicology studies, but BP is usually not collected. Overall, telemetry-based methods account for 61 % of ECG recordings; while much less frequent, restraint-based methods are used for 44 % of BP recordings, when collected. The choice and usage of collection methods is highly sponsor-dependent, with restraint-based methods for individual sponsors ranging from 0 to 100 %. Data showed that telemetry-based methods are predominately used in short-duration studies for drug safety assessments, but restraint-based snapshot methods are used in longer-duration studies. The data compiled thus far serves as a basis to consider CV collection methods used in toxicology studies and to develop recommendations on the measurement of ECG and BP in non-rodent species in support of regulatory safety assessment studies.
Lorcaserin is a 5-hydroxytryptamine 2C (serotonin) receptor agonist and a nongenotoxic rat carcinogen, which induced mammary tumors in male and female rats in a 2-yr bioassay. Female Sprague Dawley rats were treated by gavage daily with 0, 30, or 100 mg/kg lorcaserin, replicating bioassay dosing but for shorter duration, 12 or 24 wk. To characterize exposure and eliminate possible confounding by a potentially genotoxic degradation product, lorcaserin and N-nitroso-lorcaserin were quantified in dosing solutions, terminal plasma, mammary, and liver samples using ultra-high-performance liquid chromatography-electrospray tandem mass spectrometry. N-nitroso-lorcaserin was not detected, supporting lorcaserin classification as nongenotoxic carcinogen. Mammary DNA samples (n = 6/dose/timepoint) were used to synthesize PCR products from gene segments encompassing hotspot cancer driver mutations, namely regions of Apc, Braf, Egfr, Hras, Kras, Nfe2l2, Pik3ca, Setbp1, Stk11, and Tp53. Mutant fractions (MFs) in the amplicons were quantified by CarcSeq, an error-corrected next-generation sequencing approach. Considering all recovered mutants, no significant differences between lorcaserin dose groups were observed. However, significant dose-responsive increases in Pik3ca H1047R mutation were observed at both timepoints (ANOVA, P < 0.05), with greater numbers of mutants and mutants with greater MFs observed at 24 wk as compared with 12 wk. These observations suggest lorcaserin promotes outgrowth of spontaneously occurring Pik3ca H1047R mutant clones leading to mammary carcinogenesis. Importantly, this work reports approaches to analyze clonal expansion and demonstrates CarcSeq detection of the carcinogenic impact (selective Pik3ca H0147R mutant expansion) of a nongenotoxic carcinogen using a treatment duration as short as 3 months.
Introduction: The International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) initiated a process in 2012 to revise the S1B Guideline “Testing for Carcinogenicity of Pharmaceuticals”. Previous retrospective analysis indicated the importance of histopathological risk factors in chronic toxicity studies, evidence of endocrine perturbation, and positive genetic toxicology results as potentially predictive indicators of carcinogenic risk. In addition, a relationship between pharmacodynamic activity and carcinogenicity outcome in long-term rodent studies has been reported. It was postulated that these factors could be evaluated in a Weight-of-Evidence (WoE) approach to predict the outcome of a 2-year rat study.Methods: The ICH S1B(R1) Expert Working Group (EWG) conducted a Prospective Evaluation Study (PES) to determine the regulatory feasibility of this WoE approach. Drug Regulatory Authorities (DRAs) evaluated 49 Carcinogenicity Assessment Documents (CADs), which describe the WoE for submitted pharmaceutical compounds. Each compound was categorized into a carcinogenic risk category including a statement of the value of the 2-year rat study. The outcome of the completed 2-year rat studies was evaluated in relation to the prospective CAD to determine the accuracy of predictions.Results: Based on the results of the PES, the EWG concluded that the evaluation process for assessing human carcinogenic risk of pharmaceuticals described in ICH S1B could be expanded to include a WoE approach. Approximately 27% of 2-year rat studies could be avoided in cases where DRAs and sponsors unanimously agreed that such a study would not add value.Discussion: Key factors supporting a WoE assessment were identified: data that inform carcinogenic potential based on drug target biology and the primary pharmacologic mechanism of the parent compound and major human metabolites; results from secondary pharmacology screens for this compound and major human metabolites that inform carcinogenic risk; histopathology data from repeated-dose toxicity studies; evidence for hormonal perturbation; genotoxicity data; and evidence of immune modulation. The outcome of the PES indicates that a WoE approach can be used in place of conducting a 2-year rat study for some pharmaceuticals. These data were used by the ICH S1B(R1) EWG to write the R1 Addendum to the S1B Guideline published in August 2022.
The nonhuman primate (NHP) has always been a limited resource for pharmaceutical research with ongoing efforts to conserve. This is due to their inherent biological properties, the growth in biotherapeutics and other modalities, and their use in small molecule drug development. The SARS-CoV-2 pandemic has significantly impacted the availability of NHPs due to the immediate need for NHPs to develop COVID-19 vaccines and treatments and the China NHP export ban; thus, accelerating the need to further replace, reduce and refine (3Rs) NHP use. The impact of the NHP shortage on drug development led DruSafe, BioSafe, and the United States (U.S.) Food and Drug Administration (FDA) Center for Drug Evaluation and Research (CDER) to discuss this issue at their 2021 annual meeting. This meeting identified areas to further the 3Rs in NHP use within the current nonclinical safety evaluation regulatory framework and highlighted the need to continue advancing alternative methods towards the aspirational goal to replace use of NHPs in the long term. Alignment across global health authorities is necessary for implementation of approaches that fall outside existing guidelines. This article captures the proceedings from this meeting highlighting current best practices and areas for 3Rs in NHP use.
Nonclinical testing of human pharmaceuticals is conducted to assess the safety of compounds to be studied in human clinical trials and for marketing of new drugs. Although there is no exact number and type of nonclinical studies required for safety assessments, as there is inherent flexibility for each new compound, the traditional approach is outlined in various FDA and ICH guidance documents and involves a combination of in vitro assays and whole animal testing methods. Recent advances in science have led to the emergence of numerous new approach methodologies (NAMs) for nonclinical testing that are currently being used in various aspects of drug development. Traditional nonclinical testing methods can predict clinical outcomes, although improvements in these methods that can increase predictivity of clinical outcomes are encouraged and needed. This paper discusses FDA/CDER's view on the opportunities and challenges of using NAMs in drug development especially for regulatory purposes, and also includes examples where NAMs are currently being used in nonclinical safety assessments and where they may supplement and/or enhance current testing methods. FDA/CDER also encourages communication with stakeholders regarding NAMs and is committed to exploring the use of NAMs to improve regulatory efficiency and potentially expedite drug development.
Introduction The ICH-S1 Expert Working Group (EWG) convened in Montreal, Canada in May 2017 to discuss the status of the prospective evaluation study which started in August of 2013 with the publication of the Regulatory Notice Document (RND). This status report provides a brief overview of the study’s progress and summary analysis of the first cohort of 2yr rat study outcomes in relation to their respective carcinogenicity assessment documents.
Cancer risk assessment of new pharmaceuticals is crucial to protect public health. However, clinical trials lack the duration needed to clearly detect drug-related tumor emergence, and biomarkers suggestive of increased cancer risk from a drug typically are not measured in clinical trials. Therefore, the carcinogenic potential of a new pharmaceutical is extrapolated predominately based on 2-y bioassays in rats and mice. A key drawback to this practice is that the results are frequently positive for tumors and can be irrelevant to human cancer risk for reasons such as dose, mode of action, and species specificity. Alternative approaches typically strive to reduce, refine, and replace rodents in carcinogenicity assessments by leveraging findings in short-term studies, both in silico and in vivo, to predict the likely tumor outcome in rodents or, more broadly, to identify a cancer risk to patients. Given the complexities of carcinogenesis and the perceived impracticality of assessing risk in the course of clinical trials, studies conducted in animals will likely remain the standard by which potential cancer risks are characterized for new pharmaceuticals in the immediate foreseeable future. However, a weight-of-evidence evaluation based on short-term toxicologic, in silico, and pharmacologic data is a promising approach to identify with reasonable certainty those pharmaceuticals that present a likely cancer risk in humans and, conversely, those that do not present a human cancer risk.
After evaluating a safety signal regarding pancreatitis and pancreatic cancer in patients using incretin-based drugs, the Food and Drug Administration and the European Medicines Agency conclude that assertions of a causal association are inconsistent with the data. With approximately 25.8 million diabetic patients in the United States and 33 million in the European Union alone, the growing prevalence of diabetes worldwide poses a major public health challenge. Both the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA) are committed to ensuring the safety of drug products marketed for the treatment of diabetes, and postmarketing reports of pancreatitis and pancreatic cancer in patients taking certain antidiabetic medications have been of concern to both agencies. Working in parallel, the agencies have reviewed nonclinical toxicology studies, clinical trial data, and epidemiologic data pertaining to blood glucose-lowering ...
The ICH initiated talks in June 2012 to revise regulatory guidance for carcinogenicity assessment of pharmaceutical products, stimulated in part by a proposal called Negative for Endocrine, Genotoxicity, and Chronic Study Associated Histopathologic Risk Factors for Carcinogenicity in the Rat (NEGCARC) from the Pharmaceutical Research and Manufacturing Association (PhRMA). The 2012 STP Town Hall Meeting focused on the need for change in carcinogenicity assessment strategies for pharmaceuticals. Dr. Todd Bourcier from the Division of Endocrine and Metabolic Products, U.S. FDA and a member of the FDA’s Alternative Carcinogenicity Assessment Committee, was the guest speaker and a panelist. Dr. Bourcier is also one of FDA’s representatives to the ICH S1 Expert Working Group that is discussing changes to regulatory guidelines for carcinogenicity assessment. Drs. Carl Alden and Dan Morton also participated in the panel discussion.
The ICH initiated talks in June 2012 to revise regulatory guidance for carcinogenicity assessment of pharmaceutical products, stimulated in part by a proposal called Negative for Endocrine, Genotoxicity, and Chronic Study Associated Histopathologic Risk Factors for Carcinogenicity in the Rat (NEGCARC) from the Pharmaceutical Research and Manufacturing Association (PhRMA). The 2012 STP Town Hall Meeting focused on the need for change in carcinogenicity assessment strategies for pharmaceuticals. Dr. Todd Bourcier from the Division of Endocrine and Metabolic Products, U.S. FDA and a member of the FDA's Alternative Carcinogenicity Assessment Committee, was the guest speaker and a panelist. Dr. Bourcier is also one of FDA's representatives to the ICH S1 Expert Working Group that is discussing changes to regulatory guidelines for carcinogenicity assessment. Drs. Carl Alden and Dan Morton also participated in the panel discussion.