Abstract: The present invention provides a method of coupling an aminodrug (especially a cytotoxic drug, e.g. daunorubicin or doxorubicin) and a peptide to form an aminodrug-peptide conjugate, the method comprising attaching a linker to an amino group of the drug, the linker including an aldehyde or ketone carbonyl group (derived, for example, from levulinic acid or 5-oxopentanoic acid), and forming an oxime by reaction of the carbonyl group with an O-alkylhydroxylamine derivative of the peptide (obtained, for example, by reacting the peptide with aminooxyacetic acid); aminodrug-peptide conjugates obtainable from the described method are also provided, as also are pharmaceutical compositions comprising the conjugates, and methods of using the conjugates in therapeutic medication.