(Reuters) -Johnson & Johnson reported quarterly revenue below analysts' estimates as sales from its blockbuster psoriasis drug Stelara, which is expected to face competition from biosimilar versions in some markets later this year, fell short of expectations.

The company's shares fell nearly 2% in premarket trading. Stelara sales were flat at $2.45 billion in the first quarter and came in below expectations of $2.6 billion, according to LSEG data.

J&J has struck deals to delay U.S. launches of close-copy versions of Stelara until 2025, a key patent for which expired last year. Analysts have said the delayed competition will make the drug a larger contributor for J&J's 2024 and 2025 revenue than previously anticipated.

Stelara biosimilars are expected to launch elsewhere later this year. J&J reached an agreement with Alvotech in February to launch its close-copy in Japan, Canada and Europe this year. The Luxembourg-based drugmaker can enter the Canadian market in the first quarter of this year and Japan in May.

Sales of Darzalex jumped about 19% to $2.69 billion, in line with expectations of $2.68 billion.

Darzalex, a blood cancer therapy launched in 2015, is expected to bring in sales of more than $11 billion for J&J this year, according to analysts.

On an adjusted basis, J&J earned $2.71 per share in the first quarter, beating estimates of $2.64.

The company reported total revenue of $21.38 billion, compared to estimates of $21.40 billion.

J&J now expects adjusted operating profit per share between $10.60 and $10.75 for 2024, compared with its previous forecast of $10.55 to $10.75.

The company's cancer cell therapy Carvykti, which recently received approval for use in less severely affected patients with a type of blood cancer, brought in sales of $157 million in the first quarter.

Tecvayli, another blood cancer treatment, accounted for $133 million in quarterly sales.

Carvykti and Tecvayli are among ten products J&J expects will generate peak sales of more than $5 billion.