Teva Pharmaceutical Industries has withdrawn its appeal of a US district court ruling from last summer that upheld Merck & Co's compound patent on its top-selling asthma drug, Singulair (montelukast sodium), according to court documents. Merck is expected to maintain a hold on its franchise in the US until 2012.
In August, a federal judge in the US District Court for the District of New Jersey upheld the validity of...