The Food and Drug Administration has given expedited approval to an Amgen Inc. drug that treats a rare and deadly form of leukemia, the company announced on Wednesday. The antibody drug, called blinatumomab, will be marketed by the Thousand Oaks biopharmaceutical company under the name Blinctyo. It treats a form of acute lymphoblastic leukemia by directing the body’s own immune system to combat the diseased cells. The drug was approved five months ahead of schedule after being designated a “breakthrough” therapy, which are drugs shown to make major advances in treating deadly diseases. It is to be used for patients who did not respond to other drugs or whose cancer has returned. Those patients have average survival rates of just three to five months. Amgen must conduct additional trials that show the drug extends life. About 6,000 patients are diagnosed with the disease annually in the United States. Shares closed down $1.21, or a fraction of a percent, to $168.07 on the Nasdaq. The newly merged landscaping firm of ValleyCrest Companies LLC and Brickman Group is changing its name to Brightview, the company announced on Wednesday. ValleyCrest, in Calabasas, and rival Brickman, in Rockville, Md., merged in May to form a combined company with a workforce of more than 20,000 employees and revenue topping $2 billion. Terms were not disclosed. The company said the new name reflects the “bright views” of client properties while also taking the first letters of each of the merged companies. “BrighView is more than a name,” said CEO Andrew Kerin. “It indicates what is to come.” KKR & Co. LP, a prominent New York private equity firm that owned Brickman, has a majority stake in the merged company. ValleyCrest owner, MSD Capital L.P., the New York investment firm of computer mogul Michael Dell, has a minority stake.