ZANTAC PATENT: NOVOPHARM FAILURE TO SHOW EXAMPLE 32 "INVARIABLY" LEADS TO FORM 2
ZANTAC PATENT: NOVOPHARM FAILURE TO SHOW EXAMPLE 32 "INVARIABLY" LEADS TO FORM 2 ranitidine HCl was a deciding factor in Elizabeth City, N.C. federal Judge Teffence Boyle's ruling against the generic drug firm. In his Sept. 17 decision in the Zantac patent infringement case brought by Glaxo against Novopharm, Boyle ruled that "the evidence does not support a finding that Form 2 invariably results from the practice of Example 32." Novopharm had charged that the Form 2 ranitidine HCl claimed in the 4,521,431 patent is inherent in Example 32 of the Form 1 '658 patent based on synthesis experiments performed by chemists representing Glaxo and Novopharm. Addressing that argument, Boyle wrote that "the evidence as a whole shows that the proper practice of Example 32 has resulted at times in the exclusive production of Form I and at other times in the exclusive production of Form 2." He noted that "the only practice of Example 32 at the time the '658 patent was issued was [Glaxo scientist] Collin's page 122 experiment, and that clearly produced Form I." Glaxo sued Novopharm in November 1991 for patent infringement, when the Toronto-based generic drug firm filed an ANDA with FDA to market a generic version of Form 2 ranitidine HCl upon the expiration of Glaxo's Form I patent in December 1995. The judge's decision came one month after the conclusion of a nine-day trial held Aug. 9-18 ("The Pink Sheet" Aug. 16, p. 11). The Sept. 17 ruling states that "based on the evidence, Novophann has failed to carry its burden on the defense of invalidity. The court upholds that U.S. Patent 4,521,431 is not invalid, and that Novopharm infringed the patent by filing its ANDA on Aug. 9, 1991." Judge Boyle ordered that Novopharm "not be granted approval to sell Form 2 ranitidine HCl prior to the expiration of the '431 patent [and] to refrain from the commercial manufacture or sale of within the United States of Form 2 ranitidine HCl prior to the expiration of the '431 patent" in June 2002. In addition to the inherency charge, Boyle ruled against Novopharm on its inequitable conduct and best mode allegations. Boyle determined that "Novopharm has failed to carry its burden of proving that Glaxo's submission of the Hunt declaration constituted inequitable conduct in the prosecution of the '431 patent." Boyle also found that the Collin declaration "cannot be the basis for a finding of inequitable conduct." Novopharm's inequitable conduct charge was based on its allegation that Glaxo intentionally made material misrepresentations to the patent office in two declarations submitted in response to the patent examiner's Aug. 28, 1983 rejection of the Form 2 patent application for the '431 patent. One of the declarations, the so-called Hunt declaration, contained the results of analytical tests of samples of Form 1 and Form 2 that reported to show that in the solid state the products have different crystal structure. The other declaration (the Collin declaration) claimed that "Form 2 had certain qualities which made it less difficult and expensive to manufacture than the prior art," the court decision says. As to the best mode allegation, Judge Boyle's ruling states that some "officials within Glaxo made a deliberate choice not to reveal what they believed to be the best mode of making the patented invention, but instead to protect the knowledge as a trade secret." However, the statute stipulates that in a best mode violation, the inventor must know about the best mode or be the one concealing it. The court believes'the inventor did not know about the best mode and was not consulted about not revealing the information. Novopharm argued that Glaxo failed to disclose the best mode of manufacturing Form 2 ranitidine HCl for pharmaceutical use, the azeotroping process. As expected, Novopharin said Sept. 20 that it will appeal the decision. Novopharm President Robert Gunter noted that "while Judge Boyle's ruling agrees with many points we made in court, we differ on some significant issues, and, if any one of these issues is overturned on appeal, the Glaxo patent would become invalid." Another Canadian drug company, Genpharm, is challenging the ranitidine patent through a jury trial that is scheduled to begin in May 1994 in Baltimore federal court.
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