ZENITH PROHIBITED FROM CEFADROXIL DC SALES UNTIL MARCH 2002

ZENITH PROHIBITED FROM CEFADROXIL DC SALES UNTIL MARCH 2002, when Bristol-Myers' patent for crystalline cefadroxil monohydrate (Duricef) expires, following a ruling handed down by Judge Alfred Wolin July 21 in Newark federal court. Wolin found that Bristol- Myers Squibb "is entitled" to a court order preventing Zenith from marketing its version of the cephalosporin antibiotic before "the date of the expiration of the patent which has been infringed." Reversing an earlier opinion, the court accepted Bristol- Myers' claim that Zenith's cefadroxil DC molecule converts to Bristol-Myers' patent-protected Bouzard monohydrate form of cefadroxil upon ingestion. "The Court concludes that use of converted Bouzard monohydrate by a patient who ingests cefadroxil DC is an infringing use," the ruling states. "Therefore, the sale of cefadroxil DC by Zenith would constitute inducement of infringement." The court rejected the conversion upon ingestion argument in its February decision in favor of Zenith ("The Pink Sheet" March 2, T&G-2). However, that ruling was vacated when the court accepted Bristol-Myers' motion for reconsideration April 13. In motioning to reconsider, the court conceded that it had not considered all of BMS' expert testimony on the conversion of cefadroxil DC in the stomach ("The Pink Sheet" April 27, T&G-3). The acceptance of the motion for reconsideration prevented Zenith from marketing its cefadroxil DC, which gained FDA approval later that month. Zenith attempted to rebut Bristol-Myer's argument in the most recent round of litigation by contending that "Bristol predicated patentability solely on certain manufacturing advantages achieved by the newly-discovered and claimed-Bouzard monohydrate crystal form." According to Judge Wolin's findings summarizing each side's contentions, Zenith argued that "because none of the manufacturing advantages of the Bouzard monohydrate are realized by cefadroxil DC when it allegedly converts to the Bouzard monohydrate in vivo, cefadroxil DC is not the same invention as the Bouzard monohydrate." The judge disagreed: "Although the Court has found that prosecution history estoppel limits the range of equivalents that may be found to infringe, it declines to find that the reverse doctrine of equivalents limits the scope of literal infringement. Because the converted compound is indistinguishable in any way from the patented compound, the doctrine simply has no applicability." Zenith says the company is considering its legal options. An earlier FDA suspension order against products manufactured at Zenith's Northvale, N.J. plant has been lifted, FDA advised the firm in a July 14 letter. The suspension order, sent by FDA's Newark District Office June 10, had cited the Northvale facility for process validation procedure violations ("The Pink Sheet" June 15, T&G-13). FDA says it overturned the district office's order as a result of discussions between the agency and Zenith. Zenith says it has submitted revalidation packages for the majority of its Northvale product line and will submit packages for the remainder of the line "over the next several weeks."