BOSTON (Reuters) -The U.S. Justice Department on Wednesday accused Regeneron Pharmaceuticals of manipulating Medicare's drug-pricing process by inflating the average sales price for its expensive macular degeneration drug Eylea. The department, in a complaint filed in federal court in Boston, alleged the drugmaker failed for years to report how it paid hundreds of millions of dollars to subsidize Eylea purchases by reimbursing drug distributors for credit-card processing fees. Those payments wer