** Shares of biotech firm Enliven Therapeutics ELVN.O rise 3.59% to $38.33 premarket

** Co says its experimental drug ELVN-001 for chronic myeloid leukemia, a type of blood cancer, showed encouraging early-stage results

** Says 61% of patients in key group saw major disease reduction; ~50% achieved this within 24 weeks

** Adds patients with prior one or two treatments showed higher 67% response rate

** Co says study enrolled 161 patients, most pretreated; only 6% discontinued due to side effects

** Says FDA agreed to key design for late-stage study and use of 80 mg dose vs standard treatments

** As of last close, stock up about two-fold YTD