So this positive regulatory news should help to keep the momentum going, even if it was somewhat expected by the Street. Now what : Roche and Exelixis recently rolled out plans to explore cobimetinib's activity in solid tumors, when used in conjunction with immuno-therapies such as anti-PD-L1s. If the drug can show anti-tumor activity in these early stage trials, its value proposition to Exelixis shareholders would undoubtedly be greatly enhanced.