Viking Therapeutics Announces FDA Has Lifted Clinical Hold on Phase 1b Trial of VK0214 in Patients with X-ALD

Study Enrollment and Dosing to Resume

SAN DIEGO, July 19, 2022 /PRNewswire/ -- Viking Therapeutics, Inc. (Viking) (NASDAQ: VKTX), a clinical-stage biopharmaceutical company focused on the development of novel therapies for metabolic and endocrine disorders, today announced that the FDA has lifted the clinical hold placed on the clinical trial of VK0214 in patients with X-linked adrenoleukodystrophy (X-ALD). As a result, the company expects to resume study enrollment in the coming weeks.

The FDA lifted the clinical hold following its review of results from an in vivo genotoxicity study that it had requested due to the study being conducted with multiple doses in patients. Viking had planned to conduct this study prior to Phase 2 but accelerated its execution based on FDA's request. The study was completed and the results submitted to the Agency in the second quarter. The results showed no evidence of genotoxicity following exposure to VK0214. The company does not believe that the long-term development timeline for VK0214 has been significantly impacted by the temporary clinical hold.

"We look forward to resuming study activities and working to complete patient enrollment as quickly as possible," said Brian Lian, Ph.D., chief executive officer of Viking Therapeutics. "We are confident in the overall safety and potential efficacy profile of VK0214 to date, and are eager to continue its advancement as a potential disease modifying treatment for patients with X-ALD."

The Phase 1b study of VK0214 is designed to enroll patients with the adrenomyeloneuropathy (AMN) form of X-ALD. AMN is the most common form of X-ALD, affecting approximately 50% of patients. The trial is a multi-center, randomized, double-blind, placebo-controlled study in adult male patients with AMN. The primary objectives of the study are to evaluate the safety and tolerability of VK0214 administered once-daily over a 28-day dosing period. The study also includes an exploratory assessment of the impact of VK0214 on plasma levels of very long chain fatty acids (VLCFAs), as well as an evaluation of the pharmacokinetics of VK0214 in these patients.

VK0214 is a novel, orally available small molecule thyroid hormone beta receptor (TRβ) agonist that has been granted orphan drug designation by the FDA for the treatment of X-ALD. Results from a successful Phase 1 single ascending dose (SAD) and multiple ascending dose (MAD) study in healthy subjects showed that VK0214 demonstrated encouraging safety and tolerability, as well as predictable pharmacokinetics. In addition, subjects who received VK0214 experienced reductions in low-density lipoprotein cholesterol (LDL-C), triglycerides, and apolipoprotein B following 14 days of treatment. 

X-ALD is a rare and often fatal metabolic disorder characterized by a breakdown in the protective barriers surrounding brain and nerve cells; a process known as demyelination. The disease, for which there is no approved treatment, is caused by mutations in the gene for a peroxisomal transporter of VLCFAs, known as ABCD1. These mutations lead to dysfunction of the adrenoleukodystrophy protein (ALDP), an important peroxisomal transporter, which prevents patients from efficiently metabolizing VLCFAs. The resulting accumulation of VLCFAs, which is believed to contribute to the onset and progression of the disease, can trigger demyelination of nerve cells, resulting in cognitive impairment, motor skill deterioration, and even death. X-ALD is estimated to occur in approximately 1 in 17,000 births.

The thyroid beta receptor is known to regulate expression of a related gene called ABCD2, which encodes a compensatory transporter called the adrenoleukodystrophy related protein (ADLRP). Research in various preclinical disease models has shown that increasing ABCD2 expression can result in normalization of VLCFA levels.

Viking Therapeutics is a clinical-stage biopharmaceutical company focused on the development of novel first-in-class or best-in-class therapies for the treatment of metabolic and endocrine disorders. Viking's research and development activities leverage its expertise in metabolism to develop innovative therapeutics designed to improve patients' lives. The company's clinical programs include VK2809, a novel, orally available, small molecule selective thyroid hormone receptor beta agonist for the treatment of lipid and metabolic disorders, which is currently being evaluated in a Phase 2b study for the treatment of biopsy-confirmed non-alcoholic steatohepatitis (NASH) and fibrosis. In a Phase 2a trial for the treatment of non-alcoholic fatty liver disease (NAFLD) and elevated LDL-C, patients who received VK2809 demonstrated statistically significant reductions in LDL-C and liver fat content compared with patients who received placebo. The company is also developing VK2735, a novel dual agonist of the glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) receptors for the potential treatment of various metabolic disorders. VK2735 is currently being evaluated in a Phase 1 clinical trial. The company's third clinical compound is VK0214, a novel, orally available, small molecule selective thyroid hormone receptor beta agonist for the potential treatment of X-linked adrenoleukodystrophy (X-ALD). VK0214 is currently being evaluated in a Phase 1b clinical trial in patients with the adrenomyeloneuropathy (AMN) form of X-ALD. The company holds exclusive worldwide rights to a portfolio of five therapeutic programs, including VK2809 and VK0214, which are based on small molecules licensed from Ligand Pharmaceuticals Incorporated.

For more information about Viking Therapeutics, please visit www.vikingtherapeutics.com. Follow Viking on Twitter @Viking_VKTX.

This press release contains forward-looking statements regarding Viking Therapeutics, Inc., under the safe harbor provisions of the U.S. Private Securities Litigation Reform Act of 1995, including statements about Viking's expectations regarding its clinical and preclinical development programs. Forward-looking statements are subject to risks and uncertainties that could cause actual results to differ materially and adversely and reported results should not be considered as an indication of future performance. These risks and uncertainties include, but are not limited to: risks associated with the success, cost and timing of Viking's product candidate development activities and clinical trials, including those for VK2809, VK2735, VK0214, and the company's other incretin receptor agonists; risks that prior clinical and preclinical results may not be replicated; risks regarding regulatory requirements; and other risks that are described in Viking's most recent periodic reports filed with the Securities and Exchange Commission, including Viking's Annual Report on Form 10-K for the year ended December 31, 2021, and subsequent Quarterly Reports on Form 10-Q, including the risk factors set forth in those filings. These forward-looking statements speak only as of the date hereof. Viking disclaims any obligation to update these forward-looking statements except as required by law.

SOURCE Viking Therapeutics, Inc.