The FDA's approval last week of Bio-Technology General Corp.'s Bio-Tropin human growth hormone, coming on the heels of the agency's approval of Novo Nordisk A/S's Norditropin hGH, marks an end to the 10-year period of market exclusivity for Eli Lilly and Genentech Inc.

Two other products are awaiting market entry: Pharmacia AB's Genotropin will