Profit after income tax at German pharmaceutical firm Merck declined 12.5% to €699 million ($756.9 million) in the first quarter from €800 million in the same period last year, the company said on Wednesday. Earnings per share were €1.6 down from €1.83 in the previous year. Sales decreased by about 3.3% to €5.12 billion in the first quarter year-on year, Merck reported. Organic sales for the quarter were down 1.2%. Foreign exchange effects, mainly from the Chinese yuan, had a negative impact of 2% on the sales development. Merck confirmed qualitative guidance for fiscal 2024, when it expects t…