Formulation development and manufacturing of a gastrin/CCK-2 receptor targeting peptide as an intermediate drug product for a clinical imaging study.
A DOTA-gastrin analogue (APH070) which, when labelled with (111)In, has high affinity for the gastrin/CCK-2 receptor (3nM) and low tumour to kidney ratio in animal models, has been formulated and manufactured for a clinical study. Oxidation of the peptide methionine residue greatly reduces receptor affinity, therefore development work focused on producing a stable intermediate drug product (iDP) whilst ensuring that the formulation, container, closure and manufacturing process did not inhibit the extremely sensitive radiolabelling reaction (itself a source of oxidation). Stress testing revealed that APH070 was stable at 2-8 degrees C at pH 6-9. Addition of an antioxidant (monothioglycerol) to the peptide formulation reduced stability when compared to buffer alone. Use of FluroTec (4023/50) stoppers (rather than FluroTec Plus (4110/40)) increased both the stability and radiolabelling efficiency of APH070. Long term stability (6 months) of the final formulation (1mg/ml APH070 in 0.01 M pH 7.2 phosphate buffer) stored at 5 degrees C in type I glass vials with FluroTec (4023/50) stoppers was 98.6+/-0.2% and 98.4+/-0.1% for upright and inverted samples, respectively. Clinical scale radiolabelling of the final formulation routinely achieves the specification of >85% (111)In-APH070 (unoxidised) stable for up to 2h after dilution with 0.9% w/v saline solution. Specific uptake of the radiopharmaceutical in CCK-2R-expressing AR42J tumours in nude mice has been demonstrated.
Sosabowski
Jane K
JK
Department of Nuclear Medicine, St Bartholomew's Hospital, London, EC1A 7BE, UK. j.k.sosabowski@qmul.ac.uk
Lee
Myrto
M
Dekker
Bronwen A
BA
Simmons
Ben P
BP
Singh
Surjeet
S
Beresford
Hayden
H
Hagan
Susan A
SA
McKenzie
Andrew J
AJ
Mather
Stephen J
SJ
Watson
Susan A
SA
D000818:Animals; D045744:Cell Line, Tumor; D002626:Chemistry, Pharmaceutical; D002851:Chromatography, High Pressure Liquid; D004349:Drug Packaging; D004355:Drug Stability; D004356:Drug Storage; D005755:Gastrins / Q000138:chemical synthesis* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007205:Indium Radioisotopes; D007553:Isotope Labeling; D008297:Male; D008715:Methionine / Q000737:chemistry; D051379:Mice; D008819:Mice, Nude; D009374:Neoplasms, Experimental / Q000378:metabolism; D009842:Oligopeptides / Q000138:chemical synthesis* / Q000378:metabolism; D010084:Oxidation-Reduction; D019275:Radiopharmaceuticals / Q000138:chemical synthesis* / Q000378:metabolism; D043887:Receptor, Cholecystokinin B / Q000378:metabolism*; D015203:Reproducibility of Results; D012995:Solubility; D012996:Solutions; D013678:Technology, Pharmaceutical / Q000379:methods*; D013696:Temperature; D013997:Time Factors
C522059:APH070; D005755:Gastrins; D007205:Indium Radioisotopes; D009842:Oligopeptides; D019275:Radiopharmaceuticals; D043887:Receptor, Cholecystokinin B; D012996:Solutions; D008715:Methionine