Enzyme-Linked Immunosorbent Assays (ELISA) are a key tool for determining concentrations, forming a key component of many fields in the life sciences. From testing food products for allergens to detecting HIV in a patient’s blood and beyond, ELISA analysis is a vital component of a scientist’s arsenal. Quantics has been at the forefront of research…
The United States Pharmacopeia (USP) guidance on biological assay validation, General Chapter <1033>, will soon be updated. In the leadup to the publication of the new guidance, Quantics co-founder Dr Ann Yellowlees has presented on the changes at the recent BEBPA conferences in both the US and Europe. Here, we summarise some of the most…
In the most basic sense, relative potency bioassays consist of a comparison of the behaviour of a reference standard to that of a test sample. That process is not the topic of discussion here (we’ve covered it extensively elsewhere, in Potency Assay: Relative or Absolute, for example). What we want to examine is one of…
Picture the scene. You’re busily developing your assay and its data fits your chosen 4PL model beautifully. You’re just about to move onto validation—everything’s going so well!—but, out of an abundance of caution, you decide to re-run some of your data through a different software package. Disaster! It gives a different answer! Has something gone…
Relative. Thanks for reading…But wait a moment! Have you ever stopped to ask why relative potency (RP) assays are the most common potency assay? Perhaps there are cases where absolute potency (AP) would be better? Indeed, Quantics occasionally come across clients who continue to use AP for their assays. Are they incorrect? Potency is, put…
Interim analyses are common in medical device trials for a variety of reasons. Just having a look is fine, but if the outcome of the analysis could change the conduct of the trial, for example by early stopping for superiority, futility or safety, then there is a problem. If the analysis result does stop the…
Correlates of protection in determining vaccine efficacy is a topic of particular interest, given the current COVID-19 climate and the spotlight on vaccine development. Here at Quantics, we have a wealth of experience working with correlates of protection in vaccine development so we thought we would take a look back on our paper Estimating vaccine…
Bioassay simulation can be used during assay development maintenance to supplement and complement the information gained from lab experiments. Bioassay simulation assumes that the available real data is a representative sample of all the real data sets that might be created over the life of the assay. The mathematical properties of this sample can be…
Interpolation analysis is used to find the concentration of a substance in a sample. For biologics, this is often used in ELISA and other bioanalytic analyses. This blog introduces interpolation analysis for ELISA and presents a new method developed by Quantics. The Bursa-Yellowlees Method uses the available ELISA data more effectively and greatly simplifies the…
LD50 assays and challenge assays both measure the time to an event, often death, for each animal. However the standard statistical approach to the analysis of the data treats the endpoint as binary – alive / dead – at a given point in time. This is inefficient use of the data. Here, we will recommend…
We can waste about 40% of multi-well plates to avoid biasing the relative potency (RP) due to the “edge effect”. Quantics recently used a Latin square design to support a batch release assay designed to eliminate variation across the whole assay plate. This design allowed row and column effects to be identified and correctly accounted…
In our previous blog we looked at study populations and the issues that often arise along with the best practices for dealing with them. One of the issues we highlighted was missing data so this 5th clinical trial blog from Quantics Biostatistics discusses what actions can be taken when study endpoints are missing from the…
The Safety Population is used for the analysis of safety, including adverse events, toxicity and laboratory evaluations. A patient should be included if, and only if, they actually received a study treatment (even if it is a placebo). This set of patients are grouped for analysis according to the treatment they actually received, as opposed…
The Safety Population is used for the analysis of safety, including adverse events, toxicity and laboratory evaluations. A patient should be included if, and only if, they actually received a study treatment (even if it is a placebo). This set of patients are grouped for analysis according to the treatment they actually received, as opposed…
The Safety Population is used for the analysis of safety, including adverse events, toxicity and laboratory evaluations. A patient should be included if, and only if, they actually received a study treatment (even if it is a placebo). This set of patients are grouped for analysis according to the treatment they actually received, as opposed…
This 3rd clinical trial design blog from Quantics Biostatistics takes an introductory look at how the various types of clinical endpoints (introduced in our previous blog) determine the recommended calculations for what can be inferred from summary data. Formal statistical testing for a clinical trial is traditionally based on the concept of proof by contradiction….
In our last blog we discussed sample size choice and identified the key information that your statistician needs to know and why. In this second clinical trial design blog, we look at the different types of endpoints in clinical trials and some of the statistical issues they raise. Read our blog on sample size choice…
Welcome to Quantics’ Clinical blog. This blog will explore some of the statistical aspects of clinical trial design including study design, sample size, data management and analysis planning. The aims of this blog are not only to provide thought provoking insight into some of the latest statistical developments for clinical trials but also to create…