Pandemic Delays Trials Investigating Relacorilant as Endogenous Cushing’s Syndrome Treatment

The Phase 3 GRACE clinical trial evaluating Corcept Therapeutics‘ relacorilant as a potential treatment for high blood pressure and poor glucose tolerance in people with endogenous Cushing’s syndrome is expected to take longer to complete, the company announced.

While patients in the GRACE study continue to participate and some centers are still recruiting new participants, the COVID-19 pandemic “has greatly slowed new patient screening and enrollment and delayed the opening of our last few clinical trial sites,” Andreas Grauer, MD, Corcept’s chief medical officer, said in a press release.

Corcept was planning to submit relacorilant to the U.S. Food and Drug Administration (FDA) as a treatment for Cushing’s syndrome in late 2021, but the company is pushing back that submission to the second quarter of 2022.

The pandemic also has delayed by three months the start of the GRADIENT Phase 3 trial (NCT04308590), which will investigate relacorilant in people whose Cushing’s syndrome is caused by an adrenal tumor. That trial is planned to open in the next couple of months.

“Our clinical development programs continue to advance, although the pandemic has made progress more difficult,” said Joseph K. Belanoff, MD, Corcept’s CEO.

People with endogenous Cushing’s syndrome have excess cortisol in circulation — often due to a tumor in the pituitary or adrenal glands — that can increase their chances of having type 2 diabetes and high blood pressure.

Relacorilant is designed to prevent the damaging effects of excess cortisol by blocking one of its receptors. A prior Phase 2 trial (NCT02804750) has shown relacorilant can improve glucose tolerance and reduce blood pressure in Cushing’s disease patients.

The findings prompted the launch of GRACE (NCT03697109), a Phase 3 trial examining the safety and effectiveness of relacorilant in people with Cushing’s syndrome and concurrent type 2 diabetes mellitus, impaired glucose tolerance, and/or uncontrolled high blood pressure (hypertension).

GRACE is recruiting up to 130 patients with endogenous Cushing’s syndrome across the U.S., Europe, and Israel, and is being conducted in two stages.

In the first part, all will receive relacorilant for 22 weeks. Then, those with pre-established improvements in glucose tolerance or blood pressure will move into a randomized part of the trial, and receive either relacorilant or a placebo for an additional 12 weeks.

In addition to safety, GRACE’s main goal is to determine the changes in glucose metabolism in people with diabetes or impaired glucose tolerance, and changes in blood pressure among those with hypertension, during the randomized part of the trial.

“Patients who have already enrolled have continued to participate and we expect the pace of enrollment to increase as public health restrictions ease,” Grauer said.

Unlike GRACE, which is enrolling people whose endogenous Cushing’s may have distinct causes, the upcoming GRADIENT trial is designed to study relacorilant only in those whose disease is caused by a tumor or an enlargement of their adrenal glands.

These patients usually have milder disease and lack the physical signs of excess cortisol, but most also develop diabetes or hypertension as a result of the excess cortisol. There is currently no scientific consensus about how to manage them.

GRADIENT will be conducted at about 60 sites across the U.S. and Europe, and will include about 130 patients with type 2 diabetes mellitus, impaired glucose tolerance, and/or hypertension. Participants will be assigned randomly to take relacorilant or a placebo for 22 weeks, after which they may enter an extension study.

The trial’s main goals are to determine the safety of relacorilant in this patient population and to determine improvements in blood pressure and glucose metabolism.

“This quarter, we plan to start our Phase 3 GRADIENT trial of relacorilant in patients with Cushing’s syndrome caused by adrenal adenomas,” Grauer said.