Pfizer Inc said on Wednesday its experimental treatment for an inflammatory bowel disease, acquired last year as part of its $6.7 billion deal for Arena Pharmaceuticals, succeeded in a late-stage trial.

The study was testing the efficacy and safety of etrasimod in patients with moderate to severe ulcerative colitis, a chronic inflammatory disease of the colon that leads to ulcers causing abdominal pain, bloody stools and incontinence.

Inflammatory bowel disease is a $20 billion market globally, making it a lucrative target for drugmakers.

Etrasimod met the main goal of statistically significant improvement in remission at week 12 compared to placebo. Statistically significant improvements were achieved in all key secondary goals in the trial as well, the company said.