(Reuters) - Eli Lilly and Co on Tuesday reported lower-than-expected first-quarter sales for its top-selling diabetes drug Trulicity, and the U.S. drugmaker said the need to offer rebates and discounts were taking a toll and likely to weigh on revenue growth for the year.

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

Lilly has been banking on newer drugs such as psoriasis treatment Taltz and migraine treatment Emgality to grow revenue and help offset pricing pressures and sales declines for other products. However, sales of both fell short of Wall Street estimates in the quarter.

Emgality, which won U.S. approval late last year, brought in sales of just about $14 million, half of what analysts were expecting, as a program that allows patients to try newer drugs at little or no cost limited sales revenue.

“We’ve got lots of programs in place to bridge patients who may not have adequate insurance coverage or are in a high deductible phase of their plan. It’s having a negative headwind,” Chief Financial Officer Joshua Smiley told Reuters.

Similar new migraine treatments from Amgen Inc and Teva Pharmaceutical Industries have created fierce early competition and allows insurers and pharmacy benefit mangers (PBMs) to demand steep discounts to cover them, a Reuters analysis showed.

Smiley said about two thirds of Emgality prescriptions were being reimbursed. “Just based on the access decisions that PBMs and insurers have made, we expect that number to increase throughout the year,” he said.

Lilly said it expects Emgality to overtake Amgen’s Aimovig in new prescriptions in the current quarter.

Amgen on Tuesday reported first-quarter Aimovig sales of $59 million, below Wall Street estimates of $83.3 million.

Lilly also cited a number of other near-term challenges it faces, such as cheap generic competition for erectile dysfunction treatment Cialis, the recent global withdrawal of cancer drug Lartruvo after it failed to prove its benefit in a confirmatory clinical trial, and intense political pressure to lower insulin prices.

Lilly plans to offer a half-priced version of its widely-used Humalog insulin.

Eli Lilly shares closed down 2.1 percent at $117.04.

Trulicity sales of $879.7 million in the quarter fell well short of Wall Street estimates of $952 million, while sales of $252.5 million for Taltz also fell short of analysts’ estimates.

Lilly said it now expects 2019 revenue of between $22 billion and $22.5 billion, down from its prior forecast of $25.1 billion to $25.6 billion. The forecast takes into account the spin-off of animal health unit, Elanco.

Excluding items, the company earned $1.33 per share, 2 cents higher than the average analyst estimate of $1.31, according to IBES data from Refinitiv.

Revenue rose nearly 3 percent to $5.09 billion, but missed Wall Street estimates of $5.13 billion.