The US Food and Drug Administration (FDA) has placed a clinical hold on Viking Therapeutics’ Phase Ib trial of VK0214 in X-linked adrenoleukodystrophy (X-ALD) patients.

The regulatory agency has sought another preclinical study before continuing the Phase Ib trial of VK0214 for X-ALD treatment. 

Viking noted that the FDA request is not due to any data from priorly concluded or ongoing studies.

It intends to offer the information to the regulatory agency in the second quarter.

The FDA had notified the company that it considers the ongoing trial to be a Phase II trial rather than a Phase Ib. 

Before continuation with the Phase II trial, a rodent genotoxicity study is needed. 

Vikings had scheduled to carry out this study before the Phase II trial but will now expedite its execution. 

The company expects a short-term delay while VK0214’s long-term development timeline may not be affected substantially.

Viking Therapeutics CEO Brian Lian said: “We look forward to providing the FDA with the requested information in a timely fashion. 

“The current request is in keeping with industry guidance for Phase II studies and is not based on data from previously submitted or ongoing studies. 

“We are confident in the overall safety and potential efficacy profile of VK0214 and expect to submit a response with a goal to resume dosing in the study later this year.”

VK0214 is an orally available small molecule TRβ agonist.

According to findings from Phase I single ascending dose (SAD) and multiple ascending dose (MAD) clinal trial that enrolled healthy subjects, VK0214 was found to have encouraging safety and tolerability as well as expected pharmacokinetics. 

Furthermore, VK0214 treated subjects had a decline in triglycerides, low-density lipoprotein cholesterol and apolipoprotein B after 14 days.

A rare metabolic disorder, X-ALD is marked by demyelination or the breakdown of the protective barriers that surrounds brain and nerve cells. 

In June 2018, Viking concluded subject enrolment in Phase ll trial of VK2809 for the treatment of primary hypercholesterolemia and non-alcoholic fatty liver disease.