Ironwood Pharmaceuticals (Nasdaq: IRWD) announced the appointment of Dr. Jeffrey Silber as Chief Medical Officer and Head of Research and Drug Development, succeeding Dr. Michael Shetzline, who is retiring after a 30-year career.

Dr. Silber joins the Boston-based biotechnology company on July 20, 2026. He will oversee Research and Drug Development, Regulatory Affairs and Medical Affairs, reporting to Chief Executive Officer Tom McCourt. Dr. Shetzline will remain as an advisor during the transition.

Dr. Silber joins Ironwood from Vedanta Biosciences, where he served as Chief Medical Officer since 2020. Prior to that role, he held senior positions at EMD Serono/Merck KGaA, AbbVie, and Merck & Co., where he spent 16 years in roles spanning vaccines, anti-infectives and neuroscience. He holds a B.A. in biology from Harvard University and an M.D. from the Albert Einstein College of Medicine.

Separately, Ironwood announced that its confirmatory Phase 3 STARS-2 trial of apraglutide in patients with short bowel syndrome with intestinal failure (SBS-IF) was initiated in June and is now actively recruiting patients. Apraglutide is a synthetic GLP-2 analog being developed for SBS patients dependent on parenteral support.

"It's a pleasure to welcome Jeff to our leadership team," said CEO Tom McCourt in a statement. "His broad medical and scientific leadership expertise will help us build on the strong foundation we already have in place."

Dr. Silber said he looks forward to "continue executing the STARS-2 trial as we work to bring apraglutide to patients living with SBS-IF swiftly."

Ironwood also commercializes LINZESS (linaclotide) in partnership with AbbVie for the treatment of irritable bowel syndrome with constipation and chronic idiopathic constipation in the United States.