Identification of human metabolites for Phase 1 radiolabeled drugs
Identification of human drug metabolites via combined ULPC-hrMS/MS technology. Early-stage metabolite identification provides valuable insights for further studies (DDI, impairment) and prevents late-stage surprises that require new preclinical safety assessments. As an additional benefit, animal metabolism studies can be waived.
Eliminate the risk of discovering unexpected human unique metabolites in late-stage studies
Metabolite identification reveals which metabolites are formed in the human body after drug administration. Traditionally, finding out how a new drug asset metabolizes inside the human body happens in late-stage clinical studies. The industry relies heavily on animal models, which frequently fail to predict human pathways. Late-stage findings of human unique metabolites require new preclinical safety testing and may cause significant delays in drug development.
Peregrion’s metabolite identification services can be done from Phase 1. This enables timely execution of mitigation strategies for human-unique metabolites. Knowing the primary elimination or metabolic pathway early-stage helps developers focus or skip irrelevant interaction studies. For instance, if a drug is cleared solely by a non-CYP pathway and does not involve or affect CYPs, a clinical DDI study investigating CYP inhibition or induction for that specific clearance route is generally unnecessary.
Examples where early-stage metabolite identification accelerates your clinical development programs
Formation of active metabolites
Your compound is expected to metabolize into fractions with pharmacological activity. Risk mitigation strategies can be designed promptly
Drug interactions affect excretion
Drug-drug interactions are suspected play a role in the excretion of your compound’s metabolites. Early insights on the nature and quantity of metabolites support efficient design of DDI studies
Metabolite clearance is impaired
Anticipated metabolites may be difficult to clear in populations with renal and hepatic impairments. Impairment studies can effectively be designed using data on human metabolites
Practical study information for metabolite identification
| Parameter | Peregrion Approach | Client Benefit |
|---|---|---|
| Typical cohort size | 6-8 participants | limited number of participants |
| Sample matrices | whole blood, plasma, urine, feces, exhaled air, bile and vomit | full quantitative picture of metabolite abundances per matrix |
| Sensitivity range | accurate quantification and identification of metabolites with abundances as low as 1% | complete picture of all human metabolites, including the minor with potential pharmacological effects |
| Match of spectra | a single injection for metabolite quantification and identification by coupled UPLC-hrMS/MS + AMS system | 100% match between AMS and hrMS data; no issues with shifts in retention time |
| Study design | recommendations on position of radiolabel(s) and microtracer dosing | scientist to scientist interactions resulting in optimal study design for evaluating drug metabolism and excretion |
| Interindividual differences and time dependencies | flexibility on additional analysis, recommendations on studies for selected individual or timepoint samples | selection of relevant metabolites for further analyses |
Spectra of metabolite quantification and identification are fully matched by a single injection
Integrated results are generated from a single injection by coupling UPLC-hrMS/MS + AMS systems
Benefits of combining studies
- Eliminate the need for animals, time and money on animal metabolism studies
- Full mass balance and metabolite data package from a single sample
- 100% match between metabolite identification and quantification
- Decreased interindividual variability
Increased information density
Guided by Scientific Experts
Jelle Reinen
Jelle has a background in pharmaceutical sciences and holds a PhD in molecular toxicology. He has worked as a Study Director in the pharmaceutical industry since 2015. He has 3 years’ experience in the AMS field with his main focus on metabolite profiling and identification and absolute bioavailability studies.
Ioana Barbu
Ioana has a background in analytical chemistry and physics and holds a PhD in mass spectrometry. She has 5 years experience as a scientist in AMS with her focus on metabolite profiling/identification, mass balance and absolute bioavailability studies
Lotte van Andel
Lotte brings a bioanalysis background and a PhD (Netherlands Cancer Institute/NKI) in conventional high-dose human ADME studies. With six years of total industry experience, she has spent three years working as a scientist and three years as a project manager. She currently also serves as Team Lead of the Research Technician group.
Related Services
Absolute Bioavailability
Critical pharmacokinetic parameters including absolute bioavailability (F), fraction absorbed (Fa), systemic clearance (CL) and volume of distribution (Vd).
Mass Balance
Total Radioactivity in excreta, whole blood and plasma (% recovered), urine versus feces excretion (%), PK profile in plasma and whole blood, AUC, Cmax, t½. Participants can be discharged from the clinic when 90% of radioactivity has been recovered in the samples.
Metabolite Profiling
Comprehensive snapshot of metabolites in biological samples. Relative abundance (%) of parent drug and metabolites using UPLC in combination with AMS technology.
Feces Homogenization and Excretion Balance Reporting
Feces homogenization is required for effective analysis of parent drugs and metabolites. Peregrion has a dedicated microtracer-only feces homogenization facility. Using the homogenization data, Peregrion can perform rapid reporting of the excretion in urine and feces (% of dose). For this, Peregrion requires the transfer of urine weights in Excel format (as part of the shipment documentation) and the actual dose administered to the participants (single data transfer).
Support
FAQs
Which studies are redundant when microtracer metabolite identification studies are included with mass balance and metabolite profiling studies in early clinical development?
Animal metabolism studies can be waived when human metabolism data are available in the early stages of clinical development. Furthermore, the low 1 µCi radioactive dose that is used in microtracer studies does not require animal dosimetry studies prior to human ADME studies.
How can early-stage metabolite identification support the optimal design DDI and impairment studies?
The early identification of human metabolites helps inform if clinical DDI studies are warranted and how to design these specific to the pathways involved in metabolism. In case of co-medication, drug-drug interactions can occur if parent drug and drug metabolites act on the same transporters. Drug clearance can therefore be hampered, potentially causing toxicities.
Drug metabolites that are difficult to clear from the human body may have negative consequences for people with impaired renal and hepatic function. Timely information on the formation of drug metabolites can guide impairment studies. When the hepatic and renal impairment studies are done at an appropriate time in the development process, optimal dosing can be determined and the unnecessary exclusion of specific populations from prescription can be prevented.
What is the main difference between your mass balance service and metabolite profiling/identification services?
Mass balance studies are conducted to characterize excretion routes. In a mass balance study, plasma and excreta are collected until >90% is excreted. These studies provide the routes, the rates and the quantity of drug and metabolites that are found in the excreta. Metabolite profiling separates parent drug from metabolites using UPLC. AMS then measures fractions to determine where the radiolabeled material elutes, and high-resolution MS/MS works at the same retention time to support structural identification. AMS provides the total 14C quantification signal, while hrHRMS/MS provides the structural identification. You will get insight in the % of parent drug that leaves the body unchanged and the number of metabolites that are formed in amounts that warrant further investigations (>10% of parent drug).
Why are early insights on parent drug and human metabolites important?
To enable a complete safety and efficacy assessment, it is important to know to what extent patients are exposed to the drug itself but also to drug derived metabolites. For every metabolite might have toxicological or pharmacological implications by itself. Only at the moment that we know that all metabolites are accounted for in humans, it can be assessed whether these metabolites are also present the animals that were used for safety and efficacy assessments.
Is microtracer radiolabeling a requirement for human mass balance studies via AMS?
Studies with AMS technology do not require microtracer radiolabels. Studies can be performed for drug products with low (microtracer) and high (conventional) radioactivity. The technology detects 14C labeled material and has the sensitivity to detect very low doses of radioactivity of 1 µCi and less in contrast to the conventional LSC method. LSC can only be used for high radioactive levels of 100 µCi and more.
Can animal dosimetry studies be waived with microtracer studies?
In a mass balance and metabolite profiling study, typically 1 µCi of the 14C-labeled drug is dosed orally at or around therapeutic level, and plasma and excreta are collected until >90% is excreted. The low 1 µCi radioactive dose does not require a-priori animal dosimetry studies. This saves time and money at a stage where the chances of successful development are still relatively unknown.
At a later stage, to prepare for NDA or MAA filing, animal dosimetry studies may still be required by the regulatory authorities. This depends on the type of drug, the disease indication and bioavailability. By that time you are reasonably certain about the success chances of the drug.
Is 6 participants enough for regulators?
Indeed. 6 participants is generally sufficient for regulators. Some companies have submitted NDAs using 4 participants. The minimum depends on the compound and the disease indication and is often based on company policies.
What are the combined advantages of microtracer studies in clinical development?
Overall, the microtracer-based mass balance, metabolite profiling and absolute bioavailability studies in early clinical developments give an enormous enrichment of the data package available at early-stage without the need for separate studies to determine human ADME data. The data richness allows better study designs for follow up clinical studies, it allows earlier assessment and risk mitigation strategies for unexpected human unique metabolites, and it eliminates the need to conduct radioactive animal mass balance/metabolite profiling studies, where many animals, and much time and money are being spent on non-relevant animal metabolites.
Is human ADME data that is generated with microtracer studies acceptable for regulatory submissions?
The answer is ‘Yes’. We deliver data to our clients to support their regulatory submissions with regulatory-required or requested data such as human metabolism, routes of excretion, absolute bioavailability, and fraction absorbed. The FDA guideline on Safety Testing of Drug Metabolites Guidance for Industry (CDER) March 2020 Pharmacology/Toxicology recommends performing human in vivo metabolic evaluation as early as possible. The level of radioactivity in a microtracer study is only 0.1-1µCi. Conventional studies generally apply 100µCi. Due to the 100-fold lower radioactivity levels, ethical committees approve the use of 14C microtracers in early-stage clinical development.
