UPDATE 1-Merck, Samsung Bioepis launch discounted U.S. Remicade alternative

NEW YORK/SEOUL, July 24 (Reuters) - Merck & Co and South Korea's Samsung Bioepis Co Ltd said on Monday they have begun selling a less expensive alternative version of Johnson & Johnson's rheumatoid arthritis drug Remicade in the United States, a move that should accelerate price declines for the big-selling medicine.