IND-enabling studies represent the critical bridge between preclinical discovery and first-in-human clinical evaluation, comprising a comprehensive package of pharmacology, toxicology, biodistribution, dosimetry, and Chemistry, Manufacturing, and Controls (CMC) data that demonstrates a drug candidate's safety profile, biological rationale, and manufacturing quality sufficient for regulatory review. As a dedicated Radiopharmaceutical CRDMO and CRO, Protheragen offers integrated IND Enabling Services that guide novel radiopharmaceuticals through the rigorous preclinical and regulatory milestones necessary for Investigational New Drug (IND) submission, providing sponsors with the scientific depth, regulatory foresight, and documentation excellence required to advance from bench to bedside with confidence.
IND-enabling studies for radiopharmaceuticals constitute a multifaceted preclinical program designed to establish the safety, efficacy, and quality of a novel radioactive drug candidate before it is administered to human subjects. Unlike conventional pharmaceuticals, radiopharmaceutical IND packages must address both the pharmacological properties of the targeting vector and the radiation safety profile of the attached radionuclide. The core components include pharmacology studies that demonstrate the mechanism of action, target specificity, and proof-of-concept imaging or therapeutic efficacy in relevant animal models; toxicology studies that evaluate both ligand-induced toxicity (using the non-radioactive 'cold' compound) and radiation-induced toxicity (derived from biodistribution and dosimetry data); biodistribution and dosimetry studies that map the spatial and temporal distribution of the radiopharmaceutical across organs and tissues to estimate absorbed radiation doses; and CMC documentation that details the manufacturing process, quality control specifications, stability data, and analytical validation necessary to ensure batch consistency and patient safety.
Fig 1. Radiopharmaceutical target-driven early-phase enrichment trial designs. (Kunos, Charles A., et al., 2021)
Protheragen delivers comprehensive IND Enabling Services specifically tailored for the radiopharmaceutical industry, integrating preclinical pharmacology, GLP toxicology, biodistribution and dosimetry studies, CMC documentation, and regulatory strategy into a cohesive, milestone-driven program. Our integrated CRDMO and CRO platform ensures seamless coordination between radiochemistry, analytical development, in vivo imaging, toxicology assessment, and regulatory writing—eliminating vendor handoffs, accelerating timelines, and generating the robust, audit-ready data packages necessary for successful IND submission and first-in-human clinical trial initiation.
We carry out in vitro cell binding, uptake and competitive assays to verify target affinity of radiopharmaceuticals. Multiple mouse tumor models including PDX and orthotopic xenografts are applied for in vivo proof-of-concept tests on tumor uptake, imaging performance and anti-tumor efficacy. Dose-response and survival analyses define therapeutic activity, and all trial designs align with clinical administration schemes to supply valid data for investigator brochures and clinical protocols.
Our GLP-compliant toxicology tests follow FDA, ICH and OECD standards to characterize radiopharmaceutical safety. Single-dose studies for diagnostic tracers and repeated-dose trials for therapeutic radiopharmaceuticals detect radiation and ligand-related toxicity via histopathology, hematology and clinical chemistry tests. We assess cardiovascular, respiratory and neural safety pharmacology, plus local tolerance and genotoxicity as needed. Full GLP study reports are available for regulatory filings.
We run multi-timepoint in vivo biodistribution tests on rodents and primates via PET, SPECT or gamma counting to quantify radiotracer retention in tumors and organs. MIRD, OLINDA/EXM and Monte Carlo tools calculate human organ absorbed doses, with special microdosimetry analysis for alpha nuclides. ADME testing covers plasma PK, protein binding, metabolites and excretion routes to guide clinical dose setting and radiation risk evaluation.
We assemble complete ICH-compliant CMC dossiers for IND applications, covering precursor characterization, radiolabeling SOPs, batch records, QC specs and three-batch stability data with fully validated analytical methods. Our team drafts IND Module 3, investigator brochures and clinical plans, and organizes pre-IND authority communications. All documents are audit-ready for standard, exploratory or microdose IND pathways.
Protheragen's IND Enabling Services follow a structured, milestone-driven workflow designed to generate robust preclinical data and regulatory documentation that support a successful IND submission and efficient first-in-human trial initiation. Our integrated approach coordinates scientific, regulatory, and manufacturing activities to minimize development risk and accelerate clinical translation.
Whether you are advancing a novel diagnostic radiotracer toward an exploratory IND, preparing a comprehensive traditional IND package for a therapeutic radiopharmaceutical, or seeking strategic guidance on the optimal regulatory pathway for your program, Protheragen is ready to support your vision with the scientific depth, regulatory expertise, and integrated infrastructure it demands. Reach out to us today to discuss how our IND Enabling Services can accelerate your radiopharmaceutical from preclinical validation to first-in-human clinical trials. Contact our regulatory strategy team to schedule a consultation and explore a tailored partnership approach.
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