Stifel Nicolaus initiated its coverage on ImunoGen (NASDAQ:

) with a Hold rating. Stifel Nicolaus said, "Given the relatively short lifespan of the T-DM1 royalty stream (compared to the branded life span of most biologic therapies, such as Epogen, Rituxan, and Herceptin itself, which can run 15-20 years), we expect ImmunoGen to re-invest the royalties as opposed to driving EPS growth. As a result, we believe there is little upside potential for the shares from current levels, even if T-DM1 sales exceed expectations." ImmunoGen closed at $13.92 on Thursday.