H.C. Wainwright analyst Debjit Chattopadhyay views the risk/reward for shares of ImmunoGen as favorable into the Phase 3 Forward I readout. If the study meets its primary objective of statistically significant improvement in progression free survival in the overall population, the stock could trade around $20, representing a 350% upside from current levels, Chattopadhyay tells investors in a research note. If progression free survival is statistically-significant only for the patients with high FRa-expression, representing about 60% of the enrolled population, the stock could trade in the $13 to $16 range or about a 250% upside from current levels, adds the analyst. And if Forward I disappoints, the stock could trade between $2 to $3 range, or about a 55% downside from current levels, says Chattopadhyay. He keeps a Buy rating on ImmunoGen with an $18 price target.