Aug 4 (Reuters) - Vertex Pharmaceuticals VRTX.O beat Wall Street estimates for quarterly results on Monday, helped by demand for its new cystic fibrosis drug and product launches.

Revenue rose 12% to $2.96 billion in the second quarter, topping analysts' average expectation of $2.91 billion. Its adjusted profit of $4.52 per share also topped estimate of $4.26.

However, shares fell more than 11% in after-hours trading after the company said it would halt development of its experimental painkiller after it failed to provide statistically significant relief in a mid-stage trial.

Vertex, a leader in cystic fibrosis drugs, has been diversifying into gene therapies, including Casgevy for sickle cell disease and transfusion-dependent beta-thalassemia, and non-opioid painkillers.

Prescription numbers for pain drug Journavx have picked up, but analysts have said further acceleration is needed for the company to meet its annual targets.

As of July 25, Journavx generated a total of 79,763 prescriptions since its launch, according to weekly prescriptions data from Jefferies analysts.

In July, the European Union approved Vertex's next-generation CF treatment, Alyftrek. This once-daily treatment for the rare and progressive genetic disease further cemented the company's market dominance in CF treatments and paved the way to expand its global reach.

Cystic fibrosis is a genetic disorder caused by the absence of a specific protein, leading to abnormal salt and water transport in and out of cells across different organs.

Sales of the company's older CF treatment, Trikafta, came in at $2.55 billion, missing analysts' average expectation of $2.62 billion, according to LSEG data.

Vertex reaffirmed its 2025 revenue forecast in the range of $11.85 billion to $12 billion and said that it accounts for only a minimal cost impact from tariffs at current rates and regulations.

(Reporting by Padmanabhan Ananthan in Bengaluru; Editing by Sriraj Kalluvila)

((Padmanabhan.Ananthan@thomsonreuters.com;))