ROCHE GROWTH HORMONE PATENT DID NOT "ENABLE" PROTROPIN

ROCHE GROWTH HORMONE PATENT DID NOT "ENABLE" PROTROPIN manufacture, a San Francisco Federal Court judge noted Aug. 4 in a ruling in favor of defendant Genentech. "Despite strong continuing interest in synthesis of human growth hormone," the decision states, "researchers in the field were unable to totally synthesize the hormone in a usable form" using the method covered by the Roche patent. "The [Roche] patent therefore did not enable the making and using of the claimed invention." The suit, filed by Roche in September 1986, claimed that Genentech's recombinant hGH product infringed on a 1974 patent licensed by the Hormone Research Foundation to Roche. The patent, No. 3,853,833, covers a product chemically different from both Protropin (somatrem) and naturally occurring hGH, as well as an apparently obsolete production process -- solid phase peptide synthesis. "Protropin differs from the structure identified in [Roche's patent] in that it contains two additional proteins (192 instead of 190) and has slightly different proteins in the positions corresponding to positions 73 (glutamic acid rather than glutamine), 106 (aspartic acid rather than asparagine) and 108 (asparagine rather than aspartic acid) of the protein sequence shown in [Roche's patent]," the court said. Protropin also differs from the naturally occurring hormone by a single methionyl group. That difference was noted in an earlier court decision against Genentech, which challenged the orphan exclusivity of Lilly's recombinant product Humatrope. The court ruled that the Lilly product, which has a structure identical to the natural substance, was different from Protropin and therefore entitled to market exclusivity ("The Pink Sheet" Sept. 28, 1987, p. 6). That decision has postponed the introduction of Genentech's second-generation product, Protropin II, for seven years. "The properties are different, and in chemical structures as sensitive as these, the literal infringement showing must be exacting," the most recent court decision states. "Genentech's synthetic hGH does not have a structure corresponding to the structure of [Roche's patented product]." Ironically, Lilly avoided similar litigation with Roche through a sublicensing arrangement.