GSK/Xceleron deal introduce AMS to pharma

GlaxoSmithKline are to commission the pharmaceutical industry's first in-house Accelerator Mass Spectrometry (AMS) facility, with the primary aim of providing information on human metabolite formation of new drug candidates and detail pathways of drug metabolism.

AMS has been used in the study of metabolism of xenobiotics in animals and humans, pathways of biomarkers, metabolism of endogenous molecules including DNA and protein binding studies.

The drug makers are to be assisted by UK consultancy specialists Xceleron, who currently use its AMS technology to provide ongoing analytical research services to GSK.

GSK intend to purchase two small AMS machines from the National Electrostatics Corporation, USA to set up two AMS facilities, one in the UK and one in the USA.

AMS is a process, which physically separates elemental isotopes on the basis of mass, charge and potential energy differences. The technique itself centres on the separation of elemental isotopes at the single atom level. AMS was first used in the early 90's for the analysis of biological samples containing enriched 14C for toxicology and cancer research.

The nanotechnology of accelerator mass spectrometry (AMS) in drug development has been proven to speed drug development and reduce attrition rates, greatly enhancing its versatility and functions. It is up to 100,000 times more sensitive than liquid chromatography-mass spectrometry (LC-MS) and 1,000,000 times more sensitive than liquid scintillation counting (LSC).

This enabling technology relies on this ultrasensitivity when administering sub-pharmacological doses to humans at 'human phase 0' allowing invaluable PK data in the ultimate target species to be obtained. In this way a rank order for human PK for multiple drug candidates can be produced eliminating no-go drug candidates earlier and more cheaply.

The importance of PK and ADME data in early phase drug development has become increasingly significant especially when 40 per cent of new drugs 'fail' during Phase I trials.

By adding a small quantity of lightly labelled drug candidate into a Phase I study and taking excreta samples for AMS analysis, rates and routes of excretion can be determined. Hence invaluable mass/balance data can be provided at a much earlier stage than ever before. This removes the need for a future dedicated mass/balance study saving money, time and providing more information earlier to assist in the development of the drug candidate.

AMS also enables absolute bioavailability studies to be performed in which a conventional oral pharmacological dose of drug is given simultaneously with a lightly labelled IV microdose. These studies are usually difficult to conduct due to insolubility of the drug for the IV dose, analytical sensitivity issues and the fact that normally IV toxicology is required to support the study. By using AMS no IV toxicology is required.

The AMS technology is also useful for obtaining metabolic profiling information, assisting in the determination and development of the most appropriate animal models with early human data.