Viking Therapeutics is launching a Phase 1 clinical trial testing increasing doses of VK0214, its oral investigative molecule to treat adrenoleukodystrophy (ALD), against a placebo in healthy people.
“We are excited to advance VK0214 into clinical development to evaluate as a potential treatment for X-ALD, a progressive, debilitating disease for which there is no approved therapy,” Brian Lian, PhD, CEO of Viking Therapeutics, said in a press release.
ALD, also known as X-linked ALD (X-ALD), is a metabolic disorder caused by mutations in the ABCD1 gene that prevent the ALD protein (ALDP) from being made correctly.
ALDP is a transporter protein that is essential for the degradation of large fat molecules, called very long‐chain fatty acids (VLCFA). When ALDP does not work as it should, VLCFAs accumulate in some regions of central nervous system (CNS, the brain and spinal cord), increasing brain inflammation and damaging nerve cells.
However, an alternative VLCFA transporter, known as ABCD2, can compensate and allow fatty molecules to be degraded. ABCD2 levels are controlled by the thyroid beta receptor (TBR), whose activity can be enhanced by VK0214.
By increasing TBR’s activity and, consequently, ABCD2 levels, VK0214’s use may lead to VLCFAs degradation.
Data from preclinical studies in a mouse model of X-ALD showed that treatment with VK0214 can activate TBR, increasing levels of the transporter ABCD2 in the animals’ liver and brain.
Moreover, levels of VLCFAs in the blood, liver and brain of animals treated with VK0214 were significantly lower compared to untreated mice, supporting VK0214’s potential benefits as a disease therapy.
“Our prior results in this area indicate that the thyroid receptor beta is an important regulator of VLCFA metabolism, and we look forward to demonstrating the therapeutic potential of VK0214 in combatting this disease,” Lian said.
The new Phase 1 trial will assess the safety and tolerability of single and multiple ascending oral doses of VK0214 in healthy participants, randomly assigned to either the treatment or a placebo.
Identifying optimal VK0214 doses for further clinical studies as well as the therapy’s pharmacokinetics — its absorption, distribution, metabolism in the body and its excretion — will also trial goals.
“The safety, tolerability and pharmacokinetic data from this study will provide key insights for future trials of VK0214 in patients with X-ALD,” Lian said.
Once these steps are successfully completed, a Phase 1b study in patients with X-ALD is planned.
Of note, VK0214 was designated an orphan drug by the U.S. Food and Drug Administration as a potential X-ALD therapy. Orphan drug status gives a pharmaceutical company developing treatments for rare and serious diseases certain benefits, including a seven-year window of market exclusivity should the treatment be approved.
