Dublin-based biotech Amarin Corp. plc's stock took a ride upward Friday, one day after releasing first-quarter financial results that gave an early glimpse of how sales of its newly approved heart medication, Vascepa, are proceeding.

Amarin, which has research-and-development headquarters in Groton, said it has seen a near-quadrupling of Vascepa prescriptions since its first full month of sales in February. The company added that more than 4,000 clinicians nationwide have prescribed Vascepa at least once.

The sales trajectory boosted Amarin's stock price Friday as it ticked up by more than 6 percent. The price closed on the Nasdaq exchange at $7.25, up 42 cents.

"We've seen great script trends so far," Joseph Zakrzewski, Amarin's chief executive, said during a conference call Thursday. "We like responses from the doctors, the managed care, we like the shipping patterns, the buying patterns. ... It feels right to us."

Zakrzewski added that managed-care companies are embracing Vascepa as well.

"We're about three to six months ahead of where we expected," he said.

Vascepa saw prescriptions rise from 3,224 in February to 11,768 in April, according to sales figures. The company also reported progress in training clinicians to speak on behalf of Vascepa, noted that the quarter saw a doubling of its patents to 22 and cited encouraging feedback regarding patients' initial response to the fish-oil medication.

In the past few weeks, Amarin also has received regulatory approval to add two more suppliers to its fold, with the potential of significantly cutting costs.

Amarin's product sales were $2.34 million in the first quarter, but the company still reported a loss of $62.2 million as it ramped up its sales force, stocked up on Vascepa and continued to study the drug's effect on patients with high levels of a type of fat known as triglycerides in the blood.

Amarin's cash burn for the quarter was $58.4 million, but the company said it had enough money on hand to complete its so-called ANCHOR study that has the potential to expand Vascepa's market by 10 times when compared with the number of patients that the drug currently targets.

"Looking at this early trajectory, the Vascepa launch has shown nice strength, comparable to some recent big-pharma cardiovascular launches," Zakrzewski said. "We are witnessing many positive signs in the market, and we are encouraged by the progress our (275) sales professionals are making out in the field."

l.howard@theday.com

Amarin highlights

• Vascepa launched in January, with $2.3 million in sales through March

• 90 million now can access Vascepa through insurance

• Added BASF and Chemport to list of active pharmaceutical ingredient suppliers

• Increased approved patents from 11 to 22