Detection of CJC‐1295 in Equine Plasma by ELISA

CJC-1295 is a peptide-based drug that stimulates the endogenous production of growth hormone (GH). Compared to other growth hormone releasing hormone (GHRH) analogues, CJC-1295 has an extended half-life due to a drug affinity complex (DAC) that chemically crosslinks the peptide to plasma proteins containing free cysteine residues. As a result, CJC-1295 behaves more like a protein doping agent than a typical peptide-based drug. Using monoclonal antibodies raised against the CJC-1295 peptide, an ELISA was developed for the detection of CJC-1295 protein conjugates in equine plasma at concentrations as low as 12.5 pg/mL. The effectiveness of the assay for controlling the illicit use of CJC-1295 was demonstrated using equine blood samples, obtained from thoroughbred racehorses, following subcutaneous administration of 10 mg of CJC-1295.