Pharmacodynamic Biomarker Assays

Industry studies have identified a lack of efficacy as a cause of failure in 38% of programs in Phase I and 84% of programs in Phase II. Poor target validation or a lack of target engagement can be a primary cause of failure. Pharmacodynamic biomarker assays can help demonstrate target engagement and confirm proof of mechanism (POM), a key component to improve probable success in a trial.

Graph showing the success rate of clinical trials using PD Biomarkers for proof of mechanism (POM).

Our expertise in immunology allows us to map immune function in the clinic. Through implementation of a validated set of analytical, cellular, and even functional assays, as part of the clinical team in Phase 0-II studies, confirmation that the drug is engaging with the target and is having the effect predicted is key to a successful program.

This video featuring Russell Garland, our Group Leader of Analytical Services, discusses the advantages of using clinical efficacy biomarkers.

 

 

  • Video Transcript
    Carina (00:08) So Russell, how can these in vitro assays be used in early phase one and two trials?
    Russell (00:14) So the main aim of phase one and two clinical trials is to establish the safety and tolerability of the drug therapeutic. However, what we're increasingly realizing and a lot of sponsors are increasingly realizing, is that if we can include exploratory biomarkers at this stage, particularly pharmacodynamic or response biomarkers, we can use these to establish during this first-in-human stage whether their drug therapeutic is having the required mechanism of action when it first may go into man.
    Carina (00:45) So what is the main purpose of having biomarkers at this stage?
    Russell (00:51) So the PD, so pharmacodynamic or response biomarkers typically we'll be taking samples from before and after treatment of a candidate on a drug trial to establish whether the immune modulation has happened as you would have predicted from the in prior preclinical in vitro assays.
    Carina (01:09) And this is primarily speaking to immunology versus oncology or immuno-oncology?
    Russell (01:15) Sure. So immunology covers a range of therapeutic endpoints in the context of autoimmunity. You might be looking to suppress an immune response in the context of immuno-oncology or infection. You may be wanting to improve or enhance an immune response and the immune platforms at our disposal can be used in either of those situations depending on sponsors' needs.
    Carina (01:37) And so these PD biomarkers, the same ones that can be used in preclinical, you can translate over into the clinical phase in either of these therapeutic areas?
    Russell (01:46) So typically what we consider to be our sweet spot building on our preclinical immunology experience is where we have early phase clinical trials with the need for an exploratory biomarker, particularly a PD response biomarker which requires a functional immune assessment. What we typically don't have is an off the shelf panel of pre-validated assays because each assay will need some validation for a trial. It's certainly typical or possible to measure direct measurements of PD biomarkers in serum or plasma, but in the absence of any activation, quite often a lot of immune markers don't show very much, so this means we are going to need to do a phase of ex vivo activation on receipt of the samples. What this means is we need to think through the logistics of sample shipping and any delay between the blood draw and the blood processing in order to understand whether the assays will tolerate such a delay.
    Carina (02:32) So with the going through this whole process from preclinical to clinical, have we had clients that have gone through that whole process with us?
    Russell (02:50) Yeah, typically it does make it easier when we have sponsors we've been working with in the preclinical setting because we all just understand the relationship and we already understand what that drug is aiming to do and the assays we're aiming to work up so it does make the transition to the clinic a bit easier.
    Carina (03:07) Can you tell us a little bit more about the validation process?
    Russell (03:10) Sure. So in advance of a clinical trial, really it's helpful if the client is speaking to us a number of months in advance of the patient recruitment actually starting. We need to make sure we ring fence sufficient reagents of a particular batch to see us through the trial. We need to validate what happens within our four walls. So how does that batch of reagents perform, how do our analysts perform and how does our machines perform so we can control what happens within our four walls of our laboratory.
    Russell (03:41) We also need to think upstream before the sample even comes to us. So when it's taken from the patient, what anticoagulant is used, is there any shipping, is there any storage and what's the delay likely to be depending on the geographical footprint of the clinical center relative to the laboratory. So we need to kind of think through the whole process. So then we'll do a fit for purpose validation, which is really dictated by the intended purpose of the data, which is typically to inform the sponsor's decision making process for an exploratory PD biomarker rather than being a formal regulatory requirement.
    Carina (04:13) Can you tell us a little bit more about the types of samples that people would be asking us?
    Russell (04:18) Sure. The majority of samples we would use would be blood samples from some clinical trial subjects. Some assays lend themselves well to a whole blood assay where some will require peripheral blood mononuclear cell or PBMC isolation. Indeed, some of the sponsors, they just want us to prepare PBMCs freeze them and store them and then ship them to a third party for analysis, in which case that's fine. Again, we've got a geographical footprint close to a number of clinical locations, so we can help with those kinds of assays.
    Russell (04:47) Alternatively, we've got the expertise to run a number of assays ourselves, so typically it won't be a direct ex vivo measurement, although we can measure multiplex cytokines in serum and plasma for example. But as I mentioned, in the absence of any ex vivo stimulation, the backgrounds are typically quite low. So when we're looking to measure a modulated immune response, there will often be an ex vivo activation period. So whether it's a whole blood assay or a PBMC assay, we can use either a polyclonal stimulus such as anti-CD 3 and anti-CD 28 or staphylococcus enterotoxin in B and after an ex vivo activation period we can use multicolor flow cytometry, to analyze those T-cell subsets to work out how many of them are activated. So do they express activation markers such as CD 25 and CD 69 or is there intracellular cytokine production? For example, we can measure interim gamma by Il-10 to Il-17 in response to a particular angiogenic stimulus.
    Carina (05:49) You mentioned multi flow, flow cytometry as one of the platforms you use to isolate. What other types of platforms can we use?
    Russell (05:57) So that's an example of a cell based assay looking at cell based proteins, whether they be on the surface of the cell or within the cell. We can also mention the supernatants of those cultures to see what proteins are, what cytokines and chemokines are released. Typically this will be either by ELISA, if you're measuring one analyte at a time or Luminex analysis for multiple different informative cytokines so you can measure a whole host of different cytokines. But typically we would recommend a small informative panel to kind of be nice, cost effective for the client because whilst you can measure a lot of different cytokines at the same time they won't all necessarily be in range, so you need to pick them quite carefully.
    Russell (06:37) We can also use ELISpot analysis for example. So using a similar stimulus and a similar starting population, we can look at the frequency of cells that are releasing interron gamma with a kind of spot based counting technique.
    Russell (06:50) So that's another way of showing an increase in response to a vaccine, whether it be a cancer vaccine or an infectious vaccine. Then we can also look at the gene expression level as opposed to proteins either by qPCR to measure one or a limited number of targets at a time or using a bigger panel of informative markers such as using NanoString analysis where we can measure hundreds of different markers at the same time. But the common factor with all of them is in this PD biomarker setting, we'll be looking at samples from pre and post treatment to try and work out whether there's any modulation in the patient's immune response.
    Carina (07:29) So overall, what would, what is the value add for clients that would be working in this clinical PD biomarker space?
    Russell (07:43) So whilst it might seem counter intuitive, you're saving money by measuring additional PD biomarkers for and modest additional spend compared to the overall cost of an early phase clinical trial. This would be the first opportunity that clients have got when their drug goes into man for the first time to see whether the drug pathway that they predicted should be modulated is indeed modulated. So it's really important to support their go no go decision. So it was a very big financial decision and if we can add some data to help them make that decision, then it should increase the success of the drug progressing through the clinical trial pathway.
    Carina (08:09) Wonderful. Wow. It sounds like we can support clients from preclinical through clinical with these PD biomarkers and you mentioned cytokine panels, so in the space of not just the immune system but oncology and potentially neuro inflammation. That's wonderful. Thank you so much for, for sharing with us.

Available Platforms Used as Exploratory Endpoints in Clinical Trials

Cellular Protein-Based Assays

  • Multiplex cytokine assays
  • Flow cytometry
  • ELISpot

Gene Expression Assays

  • qPCR
  • nCounter® technology (NanoString)

Lead Time for Pharmacodynamic Biomarker Assay Validation Prior to Clinical Sample Receipt

Diagram of a workflow for PD biomarker assay development, validation and implementation.

Our bespoke service is tailored to the needs of your individual program. The data is intended for exploratory purposes, not for regulatory submission. Having identified a suitable platform, we will perform a fit-for-purpose validation to demonstrate pharmacodynamic biomarker assay performance and will advise on sample handling in order to ensure an optimal condition for downstream analysis.

How We Help

  • Confirming Mechanism Of Action (MOA)

    We identify and monitor PD biomarkers that confirm MOA. If your molecule affects the immune system, we can employ analytical, cellular, or even functional assays to confirm that your molecule interacts with its target modulating immunological function as anticipated.

  • Efficacy Predicting

    By carefully analyzing drug effects in the patient, our platforms support your drug discovery and development programs, providing high-quality data early in the process that will support the critical decisions taken to progress a molecule.

    Graph showing how treatments effect the production of inflammatory and anti-inflammatory cytokines.

The consequences of novel treatments on the ability of patient-derived cells to produce inflammatory and anti-inflammatory cytokines are assessed in validated pharmacodynamic biomarker assays.

Talk to an Expert

Frequently Asked Questions (FAQs) about Pharmacodynamic Biomarker Assays

  • What types of samples can be applied to PD biomarker analysis?

    The starting material for immune assays is often blood from trial subjects before and after dosing. Some assay types such as qPCR and NanoString can also be applied to tissue biopsies. Depending on the tissue, cells may also be isolated for cell-based/functional assays.

    Regardless of sample type, we are keen to ensure the best chance of success in our downstream assays, so can advise on sample handling (e.g., anticoagulants and storage), and will often comment on lab manual sections relating to endpoints.

  • How far in advance of the trial should we discuss our requirements?

    Typically, it takes a minimum of three months from study signature to get to a point where an assay is validated and given the green light to be used on clinical trial samples for a basic/established assay. More time should be allowed if an assay is particularly complex, if a new assay needs to be developed, or if prolonged sample stability testing is incorporated.

  • What pre-validated panels of pharmacodynamic biomarkers are available?

    Even though we have experience with a number of different pharmacodynamic biomarker assay platforms and panels for PD biomarker analysis, this is not a catalog service. We can advise on experimental approaches to measure biomarkers of interest, and if fit-for-purpose validation would be required to demonstrate assay performance.

  • Why do we need to include an assay validation phase?

    We need to source and test the lot of critical reagents to be used in the trial to show how they perform in our hands even when a request closely matches something we’ve run before. This ensures that the combination of assay kits, qualified operators, and our equipment gives assay performance that is fit-for-purpose. During the assay validation phase, it is also important to demonstrate that the biomarker withstands the sample handling proposed for the clinical sample phase.

  • What is the format of the PD biomarker report?

    As soon as data is available and QC has been checked, the data report will be in either an Excel spreadsheet or a PowerPoint, at a suitable frequency (e.g., batched by patient cohort). For clinical studies, a full report will be available as a Word document at the end of the trial.