Regulus Therapeutics (RGLS) shares were down 21% in recent trading Wednesday even after the company said that a portion of subjects benefited from farabursen in an early-stage study.

Interim results from the fourth cohort of subjects enrolled in the company's phase 1b study of farabursen found that patients with autosomal dominant polycystic kidney disease, or ADPKD, responded to the treatment.

The interim data was based on the first 14 subjects of the cohort who also saw a "notable reduction" in height-adjusted total kidney volume growth rate, the company said.

Additionally, all 26 subjects in the cohort demonstrated that farabursen was well tolerated, according to Regulus.

Meanwhile, the company said it had successfully concluded a meeting with the US Food and Drug Administration in December, reaching an agreement on the design of a phase 3 trial of farabursen.

Price: 0.92, Change: -0.25, Percent Change: -21.03