ZENITH ANDA APPROVAL FOR PRAZOSIN (PFIZER's MINIPRESS)

ZENITH ANDA APPROVAL FOR PRAZOSIN (PFIZER's MINIPRESS) is first generic okay for the product. On Sept. 12, FDA approved the generic company's ANDA applications for prazosin HC1 1, 2, and 5 mg caps. Marketing will be delayed until Pfizer's patent expires on May 16, 1989. Zenith said that U.S. sales of Pfizer's Minipress in 1987 reached $ 118 mil., up 6.3% over 1986. The prazosin approval is Zenith's first for a new generic version of a drug product since the company's September 1987 ANDA approval of Schering-Plough's anti-anxiety agen Trilafon (perphenazine). In April 1987, Zenith was ammong the first companies to receive approval for generic cephalexin (Lilly's Keflex). The pace of Zenith's ANDA approvals is beginning to pick up. Although the company resolved most of its difficulties with FDA two years ago, new ANDA approvals have come slowly. In the last two months, Zenith has received ANDA approvals for propanolol HCl, baclofen, and fenoprofen calcium tabs. Separately, Zenith announced on Sept. 16 that it has completed a round of lay-offs, reducing the generic manufacturer's workforce by 130. "As the current workforce of 307 (126 salaried and 181 hourly) is now considered consolidated for increased efficiency, no further reductions are planned at this time," Zenith said. The company expects to realize annual savings "in excess of $ 2 mil." from the cutbacks. The company is also planning to move back to the Northvale, N.J. facility, a location that was previiously being offered for sale. The company's present site in Ramsey, N.J. has been listed for sale. The cutbacks and the move are part of the efforts of Zenith's new management, led by president and CEO Larry Weber, to bring Zenith through Chapter 11 intact. Weber was recently elevated from his position as "interim" president. Minipress XL, a once-daily, controlled release dosage form of prazosin, using ALZA's oral osmotic technology, recently received marketing approval in France. The approval was announced by ALZA CEO Martin Gerstel at a Sept. 15 analysts meeting in San Francisco. Pfizer expects to launch Minipress XL in France during the first half of 1989. An NDA for Minipress XL has been pending in the U.S. since September 1987. Pfizer'sProcardia may also soon be facing generic competition. At least one ANDA for nifedipine 10 and 20 mg tablets may already be pending. FDA approved an ANDA suitability petition from Par on Dec. 11, 1987, setting up the likelihood of a patent challenge for Procardia. Pfizer currently markets only the capsule formulation of nifedipine. Pfizer's patent on the pharmaceutical composition of nifedipine expires on Feb. 22, 1989. The company submitted a petition to FDA on Dec. 22, 1987, requesting that two patents covering nifedipine tablets be listed so that patent challenge procedures under Waxman/Hatch law would apply if an ANDA is filed for nifedipine tabs ("The Pink Sheet" Jan. 4, T&G-6). According to Pfizer, FDA denied the petition on March 30, on the grounds that the only patents that FDA is required to file under Waxman/Hatch are those which specifically refer to the version of the drug which is the subject of the NDA. Pfizer subsequently filed a complaint against FDA for refusing to list the patents, in April, in Baltimore Federal District Court. In May, Pfizer filed a motion for a summary judgment and FDA followed with a cross motion for summary judgment, FDA said. The case is still pending with no hearing dates set, the agency noted.