1.   Immunex Corp. received approval Monday from the Food and Drug Administration to sell its drug Leukine for the most common type of adult leukemia.

2.   In terms of years of life lost to cancer, melanoma ranks second only to adult leukemia.

3.   Most forms of adult leukemia are harder to treat because the cells have by then undergone genetic mutations which remove their ultrasensitivity to radiation.

4.   Few adult leukemia patients have been engrafted with placental blood.