# Preclinical

Source: https://onco.cc/terms/preclinical/  
OnCo record `preclinical` (Term). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Everything done to a potential drug before it is given to a human: lab experiments, animal testing, and the safety and manufacturing work regulators require. Most candidates never make it out.

## Summary

Preclinical development establishes that a drug hits its target, kills or slows tumours in cells and animals, can be made consistently, and is safe enough at the planned dose to test in people; toxicology in two species is normally required before the first human trial. 'Preclinical evidence' on this site means a claim supported only by such work, and the reader should discount it heavily: roughly 90% of drugs that enter human testing fail, and preclinical findings often do not reproduce even in other labs. Better models (organoids, humanised mice, patient-derived xenografts) and more rigorous reporting are attempts to shrink the gap between bench and bedside.

## Fields

- Kind: Term
- Last checked: 2026-09-09
- Also known as: pre-clinical; preclinical studies; preclinical study; preclinical data; preclinical evidence; preclinical models; preclinical model; preclinical development; preclinical stage; discovery stage; early research; bench to bedside; translational; translational research; IND-enabling; proof of concept; proof-of-concept; mechanistic studies

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Pre-clinical_development
- Wikipedia: https://en.wikipedia.org/wiki/Pre-clinical_development

## Connected records

- terms: [Cell line](https://onco.cc/terms/cell-line/), [Clinical trial](https://onco.cc/terms/clinical-trial/), [In vitro and in vivo](https://onco.cc/terms/in-vitro-in-vivo/), [Model organism](https://onco.cc/terms/model-organism/), [Organoid](https://onco.cc/terms/organoid/), [Phase 1, 2 and 3 trials](https://onco.cc/terms/trial-phases/)
- technologies: [CRISPR functional genomics](https://onco.cc/technologies/crispr-screens/), [Patient-derived organoids](https://onco.cc/technologies/organoids/), [Patient-derived xenografts](https://onco.cc/technologies/pdx-models/)
- drugs: [Fenbendazole (veterinary anthelmintic)](https://onco.cc/drugs/fenbendazole/), [Ivermectin](https://onco.cc/drugs/ivermectin/), [Mebendazole](https://onco.cc/drugs/mebendazole/)
- key papers: [Ivermectin converts cold tumors hot and synergizes with immune checkpoint blockade for treatment of breast cancer (with 2026 expression of concern)](https://onco.cc/key-papers/paper-draganov-ivermectin-cold-tumours-npj-breast-cancer-2021/), [Ivermectin in cancer treatment: should healthcare providers caution or explore its therapeutic potential?](https://onco.cc/key-papers/paper-patel-ivermectin-cancer-curr-oncol-rep-2025/), [Ivermectin, a potential anticancer drug derived from an antiparasitic drug](https://onco.cc/key-papers/paper-tang-ivermectin-potential-anticancer-pharmacol-res-2021/), [The multitargeted drug ivermectin: from an antiparasitic agent to a repositioned cancer drug](https://onco.cc/key-papers/paper-juarez-ivermectin-repositioned-cancer-drug-2018/)
- journals: [Asia-Pacific journal of clinical oncology](https://onco.cc/journals/asia-pacific-journal-of-clinical-oncology/), [British Journal of Cancer](https://onco.cc/journals/british-journal-of-cancer/), [Cancer biology & therapy](https://onco.cc/journals/cancer-biology-and-therapy/), [Cancer investigation](https://onco.cc/journals/cancer-investigation/), [Cancer reports](https://onco.cc/journals/cancer-reports/), [Cancer treatment and research communications](https://onco.cc/journals/cancer-treatment-and-research-communications/), [Chinese clinical oncology](https://onco.cc/journals/chinese-clinical-oncology/), [European Journal of Cancer](https://onco.cc/journals/european-journal-of-cancer/), [JNCI cancer spectrum](https://onco.cc/journals/jnci-cancer-spectrum/), [Journal of Clinical Investigation](https://onco.cc/journals/jci/), [Medical oncology](https://onco.cc/journals/medical-oncology/), [Oncology](https://onco.cc/journals/oncology-karger/), [Oncology research](https://onco.cc/journals/oncology-research/), [Oncology research and treatment](https://onco.cc/journals/oncology-research-and-treatment/), [Trends in cancer](https://onco.cc/journals/trends-in-cancer/)

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