Stifel analyst Annabel Samimy says that there is a high probability that Shire's SHP643, a SubQ, once- or twice-monthly prophylactic treatment for hereditary angioedema, will be successful, as the analyst says that the drug would "present a meaningful advance to current prophylactic treatment" of the disease. The analyst thinks that the treatment could expand the market for prophylaxis, as the current standard of care is administered through IV, and she expects it to create momentum for Shire's stock. Samimy notes that Phase 3 data on the drug is expected to be released soon. She keeps a $250 price target and a Buy rating on the shares.