William Blair analyst Raju Prasad calls Global Blood Therapeutics his top pick for 2019. The analyst's dive into transcranial doppler ultrasound and stroke risk in patients with sickle cell disease provides him with additional confidence on the use of TCD flow velocity as a confirmatory trial endpoint for voxelotor ahead of Global Blood's pre-new drug application meeting anticipated to occur in the first quarter. Overall, he views the stock as "substantially de-risked" with the completion of 24 weeks of therapy in the additional 118 enrolled patients in the study. He also sees Global Blood as a potential takeout candidate given the "significant" unmet medical need in sickle cell disease, the "impressive" data shown in patients with or without concomitant hydroxyurea, and the alignment of a once-daily, oral therapy dosed in perpetuity with the large pharma commercial model. He keeps an Outperform rating on shares of Global Blood Therapeutics.