Protocol Review
Share your Clinical Study Protocol and we identify which exploratory endpoints we can support: reviewing objectives, cohort structure, sample volumes, and timepoints to build a tailored scope of work.
Read our latest blog: LinkLight™ Protein-Protein Interaction AssaysLearn More
Clinical Trial Biomarker Testing
Exploratory Endpoint Analysis for Phase 1/2 Trials
Translate your preclinical biomarker strategy directly into the clinic with cost-effective, research-grade biomarker analysis for clinical trial samples, without the regulatory burden and pricing of full GCLP.
Bridging Preclinical Biomarkers into the Clinic
Exploratory biomarkers provide early pharmacodynamic signals that inform dose selection, confirm target engagement, and support Go/No-Go decisions in Phase 1/2 trials, without the cost and compliance overhead of fully qualified GCLP programs. Reaction Biology delivers these endpoints from a dedicated research campus with genuinely different processes and pricing, not a cosmetic markdown from clinical CRO rates. When exploratory markers advance toward regulatory use, our GCLP-certified sister campus at Bioassay provides a seamless upgrade path.
How it Works
Lab Manual & Logistics
We provide input on your Laboratory Instruction Manual for correct sample collection at clinical sites: heparin tubes for PIA, Smart Tubes for phospho-flow, TruCulture tubes for ex vivo stimulation. We coordinate tube ordering, chain of custody, and Data Transfer Agreements.
Sample Analysis
Anonymized samples arrive at our European laboratory, are inventoried with temperature logging, and analyzed by cohort. Data delivered per your DTA specifications — formatted and ready for your biostatistician. Demonstrated 8-week turnaround for complex multi-cohort studies.
Biomarker Advancement
Promising exploratory biomarkers can be validated (precision, accuracy, parallelism, stability, drug tolerance) and transitioned to our Bioassay GCLP campus.
Services
Plasma Inhibitory Assay (PIA)
Measures bioactive drug concentration in patient plasma rather than total drug levels. Patient plasma is applied to target-expressing cells and inhibition is compared against the drug alone dose-response curve. Critical for highly protein-bound compounds where standard PK overestimates potential effective drug levels.
- Validated for FLT3, BCR-Abl, EGFR, VEGFR2, HPK1, Aurora kinase, but could be developed for additional targets
- Requires only 0.5 mL heparin plasma
- Same assay used in preclinical translates directly to clinical PIA
Serum & Plasma Biomarker Profiling
Quantify circulating cytokines, chemokines, and growth factors using MSD electrochemiluminescence multiplex panels with wider dynamic range and femtogram/mL sensitivity versus traditional ELISA.
- Up to 18+ analytes from a single sample aliquot
- Singleplex ELISA for specialized targets (e.g., Activin A/B)
- Ex vivo stimulation via TruCulture tubes for healthy volunteer studies, if needed
Phospho-Target Profiling & Immunophenotyping
Confirm target engagement directly from patient PBMCs or whole blood via phospho-flow cytometry (pSTAT5, pERK1/2, pFLT3, pp38) with custom gating strategies agreed pre-study.
- No heavy PBMCs isolation process required (clinical sites friendly)
- Smart Tube compatible for ambient-temperature whole blood (shipment-friendly)
- Suitable for healthy volunteer and patient samples
Platform Advantages
Cost Savings
Our dedicated research campus runs different processes with fundamentally lower overhead than GCLP-certified facilities.
Preclinical-to-Clinical Continuity
Clients already using Reaction Biology for preclinical PIA, phospho-profiling, or cytokine analysis extend the same assays to clinical samples. No method transfer, no new vendor qualification.
Speed & Operational Expertise
8-week demonstrated turnaround from protocol signature to final data delivery. ICH-GCP accredited staff with direct clinical study coordination experience across international trials.
Flexible Target Coverage
PIA validated for FLT3, BCR-Abl, EGFR, VEGFR2, HPK1, and Aurora kinase — with capability to adapt our cellular kinase portfolio to new targets as programs demand.
Applications and Case Studies
- Phase 1 FLT3 Inhibitor Program
Phase 1 FLT3 Inhibitor Program
A biotech developing a novel FLT3 inhibitor for relapsed/refractory AML engaged Reaction Biology for comprehensive exploratory biomarkers across 8 healthy volunteer dose-escalation cohorts and multiple AML patient cohorts. Services included PIA, phospho-flow (pERK1/2, pFLT3, pp38, pSTAT5), MSD 18-plex cytokine profiling, Activin A/B ELISA, and pIRAK4 AlphaLISA. The program began with preclinical PIA development and expanded seamlessly into clinical sample analysis. 8-week turnaround per cohort batch, with Lab Manual development, Smart Tube coordination, and multi-site chain of custody managed throughout.
Frequently asked questions
What is the difference between exploratory and qualified biomarkers?
Exploratory biomarkers investigate hypotheses in clinical trials — confirming target engagement, evaluating PD responses, or informing dose selection — without the GCLP validation and regulatory documentation that qualified biomarkers require. Faster and less expensive to implement while still providing critical mechanistic data. This is especially of interest when you want to have a proof the drug level is effective to influence the signaling pathway (earlier than efficacy readouts).
What is the difference between binding assays and functional assays in safety screening?
Binding assays (radioligand displacement, fluorescence polarization) measure whether a compound occupies a target. Functional assays (FLIPR calcium flux, patch clamp electrophysiology, reporter gene) measure cellular response—distinguishing agonists from antagonists. InVEST panels use binding for most targets and functional assays where mechanism of action changes clinical interpretation, such as ion channels and select GPCRs.
What is PIA and why use it instead of standard PK?
PIA measures bioactive drug concentration by incubating patient plasma with target-expressing cells. For plasma-bound compounds, standard PK overestimates effective drug levels. PIA captures the fraction that actually reaches the target — originally developed at Johns Hopkins for FLT3 inhibitors and since validated for multiple kinase targets.
What happens when exploratory biomarkers need GCLP qualification?
We validate the method (precision, accuracy, parallelism, stability, drug tolerance) and transfer it to our GCLP-certified Bioassay campus. Same organizational framework: no vendor re-qualification or method re-development.
What sample types and volumes are required?
PIA requires 0.5 mL heparin plasma. Cytokine profiling uses plasma or serum. Phospho-flow uses PBMCs or Smart Tube whole blood. All requirements are detailed in the Lab Manual we help develop for your study.
Related Services
Immunophenotyping by Flow Cytometry
Multi-parameter spectral panels for preclinical and translational immune cell profiling in tumor tissue and blood.
Multiplex MSD Assays
Sensitive electrochemiluminescence quantification of cytokines, chemokines, and growth factors from preclinical samples.
GCLP Bioanalytical Services
Regulatory-grade biomarker testing, neutralizing antibody, and ADA immunogenicity analysis via our certified Bioassay campus.
In Vivo Pharmacology
Syngeneic, xenograft, and humanized mouse models with integrated biomarker and immunophenotyping endpoints.
Discuss Your Clinical Biomarker Strategy
Assess exploratory endpoints for Phase 1 dose-escalation, functional PK via PIA, or a pathway from research-grade to GCLP-qualified biomarkers