The result of this selection process in the absence of human data is that as many as one third of drug candidates are dropped because of human PK problems. If one could obtain earlier human PK information, then candidate selection for full clinical studies should be improved. In this approach several lead candidates are 14C-labelled and administered to human volunteers at doses from as low as one microgram to up to one milligram. Parent drug concentrations are analysed by prior chromatographic separations of plasma extracts and AMS analysis of the parent drug fraction only. Armed with this information one can select the drug candidate which appears to offer the optimum PK characteristics for taking forward into full clinical studies.
Most observers believe that biotechnology is the life science industry of the future.
Already a number of human recombinant proteins are being marketed ranging from insulin to growth hormone through to fully humanised antibodies. The standard method of analysing biotech proteins is by immunoassay. This can take many months to develop and is subject to variability through cross-reaction etc. Studies have been conducted in human serum spiked with the antibody and with rats administered the antibody. The AMS approach took six weeks to label the antibody and conduct the AMS analysis compared with the normal 6-9 months to develop an immunoassay.