GLEMARK PHARMACEUTICALS said it has entered into a settlement agreement with US firm Sepracor, which could pave way for the Indian firm to launch generic eszopiclone tablets, used in treating insomnia, in the US market. “Sepracor Inc has entered into a settlement and licence agreement with Glenmark to resolve a patent infringement suit related to its filing of an abbreviated new drug application (ANDA) with the US Food and Drug Administration to market generic Eszopiclo -ne tablets,” Glenmark said in a filing to BSE. Sepracor, which markets eszopiclone tablets under the brand name Lunesta in the US market, had annual sales of $741 million.