A new treatment foe Crohn’s disease will have to wait. 

ChemoCentryx shares fell the most ever in New York trading Friday after its partner GlaxoSmithKline (NYSE: GSK) said their drug for Crohn’s disease failed in the first of four key trials.

“The results from the SHIELD-1 study are clearly disappointing but we are committed to further explore the data to determine the way forward to help patients with this chronic debilitating gastrointestinal disease,” said Paul-Peter Tak, senior vice president for GSK Immuno-inflammation R&D, in a statement.

ChemoCentryx dropped 29 percent to $8.32 at the close in New York, the biggest single-day decline since the company’s initial public offering in February 2012. The shares, the day’s second-worst performer on the Nasdaq Composite Index, had risen 9.6 percent in the past 12 months through yesterday.

Patients with moderate to severe Crohn’s disease taking the drug vercirnon weren’t more likely to respond to treatment or enter remission than those given a placebo, the Mountain View, California-based company said in a statement. London-based Glaxo halted dosing in the other studies that were under way and stopped enrolling new patients to review the findings in the trial, known as the Shield-1 study, ChemoCentryx said.

“While we are clearly very disappointed with the results from the GSK Shield-1 study, we await GSK’s decision on the future development plan for the vercirnon program following their further analysis of their data,” ChemoCentryx Chief Executive Officer Thomas J. Schall said in the statement.

The study involved 608 patients with hard-to-treat disease that hadn’t responded to prior treatment. Vercirnon was given orally either once or twice a day for three months to combat Crohn’s disease, an inflammation of the digestive tract. The drug’s development program included four trials involving more than 2,500 patients.

“GSK will continue to explore the safety and efficacy results to inform decisions about the clinical development program for vercirnon,” GSK said in a statement. “New recruitment and dosing in the ongoing clinical programme has been suspended pending further review of the SHIELD-1 results.”