San Diego drugmaker Arena Pharmaceuticals is laying off 100 employees, or 73 percent of its workforce, as part of a strategic shift in focus.

Arena has one drug on the market, the weight loss medication Belviq, which has had disappointing sales since approval.

The company says it plans to focus on developing new drugs currently being tested in clinical trials. Its pipeline includes drugs designed to treat pain, ulcerative colitis and pulmonary arterial hypertension.

This is the second time in recent years that Arena has slashed its workforce. It cut about 80 employees last fall, and downsized its office space.

"We believe our clinical-stage pipeline has the potential to deliver first or best-in-class compounds for a broad range of indications,” said Amit Munshi, Arena’s president and CEO, in a statement. “Building a streamlined and highly-focused organization supports our primary objective — developing our pipeline in a timely and efficient manner.”

The new layoffs include employees in research, manufacturing, and general and administrative staff, the company said.