Reata Stops Bardoxolone PAH Trials Amid COVID-19 Concerns

Reata Pharmaceuticals is stopping clinical trials evaluating bardoxolone methyl in people with pulmonary arterial hypertension (PAH), including a Phase 3 study, to ensure the safety of participants during the COVID-19 pandemic, the company announced.

Trials in other disorders are set to continue, although some will stop further enrollments.

“The COVID-19 pandemic presents an unprecedented threat to public health. The adjustments we have made to our studies reflect our foremost concern for the safety and well-being of study participants, clinical investigators and their site staffs, our employees and communities as we face this challenging and unpredictable operating environment,” Warren Huff, president and CEO at Reata, said in a press release.

Bardoxolone methyl is an oral, anti-inflammatory agent in development as a potential treatment for a variety of conditions characterized by excessive inflammation. The therapy is currently being tested in several trials.

The Phase 3 clinical trial CATALYST (NCT02657356) was evaluating the safety and efficacy of bardoxolone methyl in about 200 people with connective tissue disease-associated PAH (CTD-PAH), compared to placebo. Those who completed CATALYST, or other related studies testing bardoxolone methyl in PAH, were invited to enroll in a long-term extension study called RANGER (NCT03068130).

Both CATALYST and RANGER trials will be stopped due to safety concerns related to COVID-19.

“Patients with CTD-PAH have compromised cardiopulmonary [lung/heart] function, are often receiving immunosuppressants, and are at an inherently high risk of adverse outcomes in the event of infection,” the Reata press release stated. “The Company concluded that continued exposure of these high-risk patients to clinic or in-person visits presented an unacceptable risk.”

This decision was taken after consulting the study’s Data Safety Monitoring Board (DSMB), Reata said in the release.

An initial review of available CATALYST data suggested a good safety profile for bardoxolone methyl, with fewer serious adverse events reported in the treatment group than in the placebo group. No treatment-related deaths were reported, and fewer patients discontinued bardoxolone treatment compared to those given a placebo.

While formal analyses have yet to be performed, preliminary data on efficacy measures provided by the DSMB suggested that the study is “unlikely” to meet its primary efficacy endpoint, defined as a statistically significant improvement in the distance a person can walk in six minutes (a common measurement of physical fitness for ambulatory people) relative to placebo at 24 weeks post-treatment.

Reata plans to present more detailed findings from CATALYST, including a full analysis of the data, at a future medical conference.

Bardoxolone methyl is also being investigated in people with kidney disease caused by Alport syndrome in the Phase 3 CARDINAL clinical trial (NCT03019185), and in people with autosomal dominant polycystic kidney disease (ADPKD) in the Phase 3 FALCON clinical trial (NCT03918447).

CARDINAL, which completed enrollment in 2019, is continuing with alterations. Enrolled participants will give blood samples through at-home visits rather than going to clinics, and will have the therapy delivered to their home.

FALCON has not yet completed its target enrollment, and Reata decided to put further recruitment on hold, with plans to resume enrolling people “as soon as the situation permits.” For those already enrolled, the trial will continue with modifications similar to those for CARDINAL to ensure treatment access and safety in monitoring.

“We will continue to monitor and make adjustments, if needed, as we navigate this highly fluid landscape,” Huff said.

Reata believes its supply chain of bardoxolone methyl will not be substantially disturbed by the ongoing pandemic, and it will be able to meet trial demands.