Highly Potent API (HPAPI)

Discovery Solutions for Highly Potent Therapeutics

Safe, Scalable, and Integrated Discovery

The discovery of High-Potency Active Pharmaceutical Ingredients (HPAPIs) requires a unique combination of scientific expertise, specialized containment infrastructure, and early safety evaluation. Many emerging therapeutics—especially in oncology and targeted therapies—exhibit very high biological activity, making accurate potency assessment and safe handling essential from the start.

At Aragen, our HPAPI Discovery Solutions support innovators working with potentially highly potent molecules, even when exact potency and hazard classification are not yet fully known. Our seamless integrated ecosystem combines chemistry, biological evaluation, analytical characterization, and preclinical assessment under OEB-5 containment (OEL <1 µg/m³), enabling compounds to progress from hit identification to preclinical candidate nomination safely, compliantly, and efficiently at a single site.

Integrated Discovery for Potential HPAPIs

Discovery Chemistry & Compound Handling

Aragen enables seamless discovery and early development of Antibody–Drug Conjugates (ADCs) and Highly Potent APIs (HPAPIs) through a purpose‑built, OEB‑5/6 discovery ecosystem integrating chemistry, biology, analytics, and bioconjugation under one roof. Aragen’s medicinal chemistry team enables agile, reliable synthesis supported by structured workflows designed for potent molecules.

• Design and synthesis expertise across multiple potent modalities:
  • Small‑molecule cytotoxics
  • ADC payloads and linkers
  • Targeted protein degraders (PROTACs, molecular glues)
  • Potent peptides and peptidomimetics
• Structure–activity relationship (SAR) exploration to optimize potency, selectivity, and developability. Rapid data turnaround to accelerate SAR and go/no‑go decisions
• Scaffold optimization and analog generation
• Synthetic route feasibility assessment
• Integrated analytical & characterization
• Scalable support
  • 1 mg to 1 g scale for early discovery, profiling, and FFS studies
  • 5 g to 50 g scale for expanded discovery and development projects (FTE/FFS)

Highly active compounds require sophisticated chemistry and stringent safety controls. All operations are conducted in laboratories designed for the safe handling of highly active compounds, supported by controlled workflows for weighing, dispensing, solubilization, and intermediate preparation, and integrated with downstream biological and analytical workflows.

Comprehensive Potency Evaluation

Understanding compound potency early in discovery enables informed decision-making while establishing appropriate safety and containment strategies. Aragen enables this through a broad portfolio of assays designed to characterize biological activity and target engagement, including:

• Biochemical assays: enzyme inhibition, receptor binding, target-specific kinase activity
• Cell-based functional assays: for cytotoxicity and selectivity profiling
• In-vitro potency assays (IC₅₀, EC₅₀) and binding affinity

These studies provide an accurate assessment of compound’s activity, guiding optimization and candidate selection while setting the stage for safe containment practices.

Safety and Hazard Evaluation

Ensuring safe progression of potent molecules starts with early pharmacological and toxicological evaluation. Aragen conducts hazard assessments that consider:

• Pharmacological activity and receptor affinity, including in-vitro binding and functional assays to understand biological potency
• Genotoxicity and mutagenicity (Ames test and micronucleus assay)
• Carcinogenicity risk indicators associated with long-term exposure
• Reproductive and developmental toxicity
• Acute toxicity indicators (dose-range finding studies, lethal dose ranges estimation)
• Repeat-dose toxicity evaluations to identify potential target-organ effects

These evaluations support accurate Occupational Exposure Band (OEB) classification, enabling the implementation of appropriate containment and safety controls.

Biological & Mechanistic Evaluation

Generating robust functional and mechanistic data is essential for confident candidate progression. Aragen enables deeper biological insight through integrated assay platforms, including:

• Cell-based assays: viability, cell cycle & apoptosis profiling, clonogenic studies
• Biochemical assays: kinase profiling, target-specific enzymatic activity, SPR kinetics
• Immune effector function assays: ADCC, ADCP, CDC
• High-content imaging: receptor internalization, lysosomal trafficking, mitochondrial toxicity

Together, these platforms provide a comprehensive understanding of compound behavior to guide preclinical planning.

Analytical Characterization

Comprehensive analytical characterization ensures that compounds progressing toward preclinical studies are well understood in terms of identity, purity, and stability. 

• LC-MS/MS, HRMS, and Triple Quadrupole (QQQ) Mass Spectrometry for precise HPAPI quantification (including payloads)
• Purity, aggregation, and thermal stability assessment
• Solid-state characterization, including polymorphism analysis and stability evaluation under strict containment to ensure long-term drug product viability
• DAR determination and ADC-specific analytics
• Antibody and conjugate characterization: ELISA, MSD, SPR
• Payload release and metabolite profiling

All analytical workflows are fully validated, traceable, and compliant with regulatory standards.

ADME, PK/PD & Preclinical Studies

Understanding compound behavior in biological systems is essential for selecting and advancing preclinical candidates. Aragen supports this through integrated ADME and preclinical evaluation capabilities for conjugate, antibody and payload entities. Our services include:

• In vitro ADME: Buffer stability, lysosomal cleavage, permeability, efflux, DAR analysis and metabolite profiling
• Bioanalytical support: Quantitative measurements using LC-MS/MS, HRMS, ELISA, MSD platforms
• In vivo PK/PD: rodent and non-rodent exposure-response evaluations
• Preclinical efficacy and safety evaluation: proof-of-concept and tolerability assessment

This integrated platform ensures robust, reliable data for safe and informed candidate progression.

Containment, Handling, and Cleaning

Handling potent compounds requires stringent containment infrastructure and well-defined operational controls. Our facilities are designed to safely manage compounds within OEB-5 containment standards (OEL < 1 µg/m³), ensuring protection of personnel, environment, and product integrity throughout discovery workflows.

Containment Infrastructure

• Isolator-based handling systems, gloveboxes, and restricted access barrier systems (RABS)
• Restricted laminar airflow (RLAF) environments and Class-II biological safety cabinets
• Dedicated HVAC systems with HEPA filtration and Bag-In/Bag-Out (BIBO) protocols to prevent cross-contamination

Operational Controls

• Controlled workflows for weighing, dispensing, solubilization, and intermediate preparation
• Specialized automation for potent compound handling
• Restricted access areas, specialized PPE, and comprehensive personnel training

Cleaning and Environmental Controls

• Validated cleaning procedures for potent compound environments
• Dedicated waste management streams
• Environmental monitoring programs and containment verification

ADC & Bioconjugation Integration

For antibody-drug conjugate (ADC) programs, Aragen enables seamless integration between biologics discovery and high-potency payload development.

• Antibody discovery and engineering
• Bioconjugation: Chemical and enzymatic conjugation, Purification
• ADC characterization: Concentration, DAR, aSE-HPLC, SDS-PAGE, thermal stability, antigen binding

Supported HPAPI Modalities

Aragen supports discovery across diverse highly potent therapeutic modalities, including:

• Small molecules: cytotoxic agents, kinase inhibitors, natural product scaffolds
• Peptides & peptidomimetics: stapled/constrained peptides
• Oligonucleotides: antisense, siRNA, miRNA constructs
• Targeted protein degraders: PROTACs, molecular glues
• ADC payloads & linkers: auristatins, maytansinoids, PBDs

Why Aragen?

• Integrated discovery ecosystem: purpose-built high-potency discovery laboratories combining chemistry, biology, and analytics under one roof
• Safe handling and containment: OEB-5 infrastructure with validated workflows and strong personnel protection protocols
• Extensive HPAPI expertise: experience across cytotoxics, ADC payloads, kinase inhibitors, steroids, prostaglandins, and other potent modalities
• Analytical rigor: LC-MS/MS, HRMS, DAR analysis, and antibody–payload characterization
• Single-site convenience: seamless progression from discovery through preclinical evaluation