Pharmaceutical composition comprising suitable pharmaceutical excipients and also comprising a clinical effective amount in vivo in humans of a recombinant human growth hormone pegylated prodrug conjugate (rhGH), in which PEG binds to rhGH via a transient binding group self-hydrolyzable (self-cleavable)； said prodrug conjugate being characterized in that: (1): the conjugate has a GH activity that is less than 5% of the native growth hormone without PEG； and (2): the rate of binding group autohydrolysis is such that the in vivo half-life is from 10 hours to 600 hours that is measured by intravenous injection in rats of the conjugate, followed by the extraction of blood samples at intervals of time, plasma preparation and hGH analysis using ELISA； and wherein the pegylated prodrug conjugate has the chemical structure (A): ** Formula ** in which HN-rhGH represents the rhGH residue attached to the transient binding group； R1, R2, R3, R4, and R5 are independently selected from hydrogen, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl； PEG represents the pegylation residue attached to the transient binding group； n>； = 1 or 2； and X is selected from C1 to C8 alkyl or C1 to C12 heteroalkyl； and in which the PEG is branched and contains at least 3 chains.Composición farmacéutica que comprende excipientes farmacéuticos adecuados y que comprende también una cantidad eficaz clínica in vivo en seres humanos de un conjugado de profármaco pegilado de hormona de crecimiento humana recombinante (rhGH), en la que PEG se une a rhGH mediante un grupo de unión transitorio autohidrolizable (autoescindible)； estando dicho conjugado de profármaco caracterizado porque: (1): el conjugado tiene una actividad GH que es menor del 5% de la hormona de crecimiento nativa sin PEG； y (2): la velocidad de autohidrólisis de grupo de unión es tal que la semivida in vivo es de desde 10 horas hasta 600 horas que se mide mediante inyección intravenosa en ratas del conjugado, seguido por l
