Novartis AG (NOVN) said a multiple sclerosis patient died on Nov. 23 after starting treatment with Gilenya, the first pill approved to treat the debilitating neurological disease. Whether Gilenya played a role in the patient’s death can’t be excluded or confirmed, Eric Althoff, a spokesman for the Basel, Switzerland-based drugmaker, said today in an e-mailed statement. The death is the first reported within 24 hours of the first Gilenya dose in more than 28,000 patients who have taken the drug, Althoff said. Gilenya was approved in the U.S. last year and cleared for sale in Europe in March. It’s among the products Novartis is depending on to boost sales as patents start to expire on the company’s best-selling drugs, including the hypertension pill Diovan. It’s not clear yet how a single death might affect doctors’ cost-benefit analysis of the drug, Tim Anderson, an analyst for Sanford C. Bernstein Ltd., wrote in a note to investors today.