Barr Pharmaceuticals ( BRL) said the Food and Drug Administration won't require additional clinical trials for an experimental oral contraceptive called Seasonique that reduces the frequency of menstrual periods from monthly to quarterly. However, Barr didn't predict when the FDA might grant formal approval to a drug that the agency had given a conditional endorsement in August. When the FDA gave conditional approval, it asked Barr for additional data. Barr said Friday it will work with the FDA "to resolve outstanding issues," such as product labeling and post-marketing review. Seasonique is a relative of Seasonale, which was launched in November 2003 and also reduces the number of menstrual periods. Barr says 1.6 million prescriptions have been written. Although Barr specializes in generic drugs, the brand-name Seasonale accounted for $29 million of its revenue, or 9% of the total, for the second quarter ended Dec. 31. The Seasonale treatment includes a combination pill of the drugs levonorgestrel and ethinyl estradiol for 84 days, then a placebo for 7 days. The Seasonique treatment calls for 84 days of the combination pill, then an ethinyl estradiol pill for seven days. Barr's stock was off 76 cents, or 1.2%, to $61.57 Friday. Separately, Germany's Schering ( SHR) said Friday that its U.S. subsidiary Berlex received FDA approval for a new oral contraceptive called Yaz. The product, which will become available next month, combines the drugs drospirenone and ethinyl estradiol. Women taking Yaz for 24 days and a placebo for four days. The traditional treatment for contraceptives involves 21 days of an active hormone pill followed by seven days of placebo, Berlex said. Berlex said Yaz causes less hormonal fluctuations than traditional oral contraceptives. The company added that it's talking to the FDA about securing approval for Yaz as a treatment for premenstrual dysphoric disorder. PMDD is a severe form of premenstrual syndrome, leading to, among other symptoms, depression, mood swings and irritability. Berlex sells four other oral contraceptives in the U.S.