Biologically active compound conjugated to a stapled or stitched peptide

The invention relates to improvements in drug delivery and more particularly to the use of Cell Penetrating Agents (CPA's) or Cell Penetrating Peptides (CPP's) which have been stabilized by, for example: i) stapling two amino acids to form Stapled CPP's (StaP's) or ii) stitching three or more amino acids to form stitched CPP's (StiP's). These stabilized CPP's are conjugated to a drug or Biologically Active Compound (BAC) directly or via a Bi-Functional Linker (BFL) so that the BAC can be carried though a cell membrane by the CPP. The resulting molecules are referred to as Drug Carrying Cell Penetrating Molecules (DCCPM's). The preferred BAC is an electrically low charge carrying oligonucleotide such as a phosphorodiamidate morpholino oligonucleotide (PMO). The invention also relates to a method of facilitating the uptake of a BAC into a cell, the use of a DCCPM in the treatment of a disease requiring alteration of an endogenous or exogenous gene, a method of improving the bioavailability of a drug or BAC, a method of introducing a drug or BAC to a site which is refractory to the drug or BAC in its native state, a method of treating a subject comprising administering the DCCPM's of the invention and to a pharmaceutical composition comprising the DCCPM and one or more pharmaceutically acceptable excipients.