(Reuters) – Eli Lilly and Co on Tuesday reported lower-than-expected first-quarter sales for its top-selling diabetes drug Trulicity, saying they were partly hurt by programs that allow patients to try newer drugs at little or no cost to them as insurance companies weigh coverage decisions.

FILE PHOTO: The logo and ticker for Eli Lilly and Co. are displayed on a screen on the floor of the New York Stock Exchange (NYSE) in New York, U.S., May 18, 2018. REUTERS/Brendan McDermid

Shares of the U.S. drugmaker were down 2.6 percent at $116.46.

The company said net price declines in the United States could also negatively impact sales. Lilly also cited a number of other near-term challenges it faces, such as cheap generic competition for erectile dysfunction treatment