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

  • Video Transcript
    Carina Peritore(00:08) So Russell, how can these in vitro assays be used in early phase one and two trials?
    Russell Garland (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.