 FOSTER CITY, Calif.--BUSINESS WIRE--Geron Corporation Nasdaq: GERN, a late-stage clinical biopharmaceutical company, today announced the opening for patient screening and enrollment of the IMpactMF Phase 3 clinical trial of imetelstat, a first-in-class telomerase inhibitor, in refractory myelofibrosis MF. As Gerons second registration-enabling Phase 3 trial in hematologic myeloid malignancies, the IMpactMF trial represents a milestone for our Company, said Aleksandra Rizo, M.D., Ph.D., 