By Christy Santhosh

(Reuters) -Vertex Pharmaceuticals missed Wall Street estimates for quarterly results on Monday due to lower-than-expected sales of its cystic fibrosis (CF) drug Trikafta, sending shares down 2.5% after the bell.

However, the drugmaker raised the lower end of its revenue forecast, expecting its newer CF drugs and its acute pain drug Journavx to drive growth.

BMO Capital Markets analyst Evan Seigerman said the revenue miss is likely to draw scrutiny, as Vertex (NASDAQ: VRTX ) needs to execute the launch of Journavx.

The drug has generated more than 20,000 prescriptions from its launch in March through April 18. Seigerman said that the prescription numbers are "a good start", but he wants to see pull-through to revenues.

In December, the U.S. Food and Drug Administration approved Vertex’s next-generation treatment, Alyftrek. This once-daily treatment for a rare and progressive genetic disease further strengthens Vertex’s market dominance in CF treatments.

CF is an inherited disorder resulting from the absence of a specific protein, which disrupts the movement of salt and water in and out of cells in various organs.

In the first quarter ended March 31, sales of the company’s older CF treatment, Trikafta, rose 2% to $2.53 billion but missed analysts’ average expectation of $2.58 billion, according to LSEG data.

Vertex has activated more than 65 authorized treatment centers globally and 90 patients have begun cell collection for its gene therapy Casgevy, which treats a rare blood disorder that requires regular blood transfusions.

Vertex sees 2025 revenue between $11.85 billion and $12 billion, compared to the previously projected range of $11.75 billion to $12 billion.

Total quarterly revenue rose 2.7% to $2.77 billion, missing analysts’ estimates of $2.85 billion.

On an adjusted basis, the company reported a profit of $4.06 per share for the quarter, compared with analysts’ expectations of a profit of $4.32 per share.