On the heels of an FDA orphan drug designation for lead compound PU-H71 in myelofibrosis, privately held Samus Therapeutics Inc. moved the small molecule into a phase Ib dose-escalation study in patients with the bone marrow disorder. PU-H71 is designed to target the epichaperome, a protein complex present in more than half of the cancers tested by the company, a spinout of Memorial Sloan Kettering Cancer Center (MSKCC).