Canaccord Genuity’s John Newman and Andrew Lam have an update on Regeneron( REGN) Friday, warning investors to tread cautiously.

George D. Yancopoulos, founding scientist and chief scientific officer of RegeneronSociety for Science & the Public
They reiterated a Hold rating and $450 price target on the stock, but lowered their earnings estimates for this year, and the years 2017 to 2020, citing revised estimates for cash taxes, as they now expect the company to pay a 36% tax rate this year, 35% next year and 2018, and 34% beyond.

However, more importantly, they also write that there are more risks than investors realize:

We believe investors are underestimating the risk of positive Phase 3 data for Ophthotech’s Fovista by YE16, which could meaningfully pressure EYLEA revenues if positive. We recognize that suspicion remains regarding lower-than-expected control arm performance in the Fovista Phase 2. Nonetheless, we caution investors ahead of the Phase 3 data.

We would expect a steeper Praluent revenue ramp following positive outcomes data, but continue to believe that the drug will be relegated to last-line therapy. We also believe that Amgen may have a slight advantage since its outcomes data will read out before Regeneron’s, and because Amgen can continue to engage in aggressive formulary strategies to obtain better positioning for Repatha vs. Praluent.