a) General 

The cases decided following decision G 5/83 throw some light on the categories of novel and inventive therapeutic use for which the manufacture of a known substance or compound may be considered patentable. Manufacture of a known composition has been considered patentable for use in a new therapy where the target group to be treated was different (seronegative pigs instead of seropositive pigs; T 19/86, OJ 1989, 25), and in the case of a new therapy with a different technical effect (prevention of tooth decay by means of a known substance, but by removing plaque instead of by reducing the solubility of tooth enamel; T 290/86, OJ 1992, 414) or a new therapy with a different mode of administration (subcutaneous instead of intramuscular injection; T 51/93).