Cyprotex: Predictive toxicology tech will help pharma cut animal study spending

23-Nov-2015 - Last updated on 23-Nov-2015 at 13:43 GMT

Drug toxicology based on chemical structure

Cyprotex has expanded its toxicology offering with a new in silico technology it claims will reduce preclinical costs and cut the number of animal studies required.

The UK-based preclinical contract research organisation (CRO) launched the tech – chemTox – this week, explaining that the system is designed to allow drug and cosmetics developers to predict compound genotoxicity and rat LD₅₀ directly from chemical structure.

Simon Thomas, Cyprotex’s head of scientific computing, told us: “ChemTox generates a number of predictions of toxicity, but the core predictor is of acute oral dose rat LD₅₀, which is the dose that is required to kill 50% of the test cohort.

“The OECD define 5 levels of rat oral dose LD₅₀, where each level is identified by the dose (5, 50, 300, 2000 or 5000mg/kg) that causes 50% lethality. We estimate that chemTox will predict the correct class with an accuracy of 75 – 88%, depending on the dose level in question.”

Fewer animal studies

Drug developers that use the system will still need to conduct animal studies as it has not been approved for regulatory submission. However, at this stage, the idea is to reduce the number of in vivo experiments, rather than replace as Thomas explained.

“The value of chemTox in reducing the number of animal toxicity studies is realised by the early identification of toxic liabilities in compounds in the pipeline, so reducing the number of compounds that will be selected for animal testing in the process leading to selection of clinical candidates.”

Lower cost development

The in silico approach also offers potential cost saving according to Thomas, who said that: “The only significant cost of running chemTox is the cost of the licence. Predictions are made from the chemical structure, so neither compound synthesis nor generation of any assay data are required.

“The cost of running a single in vivo LD₅₀ study can be many tens of thousands of pounds. Every in vivo study that is not run in the course of a drug discovery project because of a chemTox prediction saves this cost.

N+1 Singer Equity Research analyst Sheena Berry said chemTox complemented Cyprotex’s existing in silico offering, citing both the pharma and cosmetics sector as key markets.

She said: “We maintain our view that Cyprotex has the ability to offer an expanding array of services to customers and to expand into new end markets. We remain upbeat and believe the group is capable of capitalising on additional opportunities.”