Pliant bends investors to its will, sending stock up with early evidence of efficacy in liver disease

Investors are swayed by Pliant Therapeutics’ data. The biotech posted early clinical evidence that its lead drug candidate reduces scarring and itching in a chronic liver disease, sending its share price up around 15%.

The phase 2a trial is comparing bexotegrast, an oral, dual-selective inhibitor of two integrins, to placebo in patients with primary sclerosing cholangitis (PSC) and suspected liver fibrosis. PSC, a condition with no FDA-approved therapies, causes scarring of bile ducts and cirrhosis. Through tissue specific inhibition of TGF-β, bexotegrast may block fibrosis, leading Pliant to identify it as a potential treatment for PSC.

In the phase 2a trial, participants received one of three doses of bexotegrast or placebo. While the study is primarily designed to assess safety, tolerability and pharmacokinetics, Pliant also looked at exploratory efficacy endpoints such as changes in the fibrosis, biochemistry and imaging of the liver. The exploratory endpoints revealed early signs that bexotegrast may improve outcomes. 

After 12 weeks of dosing, the ELF score, a blood test of fibrosis markers, was significantly lower in the high, 160-mg dose cohort than in the placebo group and numerically lower in all the bexotegrast arms. Pliant linked the high dose to an 84% reduction relative to placebo. The reduction was underpinned by significant declines in all three markers that make up the ELF score. 

Pliant also reported a significant drop in collagen synthesis and, at the high dose, in the score on an itch scale. Other liver biochemistry and imaging parameters favored bexotegrast, too, giving Pliant data with enough promise to send its share price up around 15% to $16.60 in premarket trading.

The data set is small—each arm featured around 20 patients—but the signs of efficacy and lack of safety red flags have encouraged Pliant and its investors. Attention now turns to the anticipated publication of 12-week data on a higher, 320-mg dose, which is scheduled for the first quarter of next year.  

Pliant is part of a small band of biotechs working to address the unmet need in PSC, a disease that companies including Gilead Sciences have targeted in the past without delivering a FDA-approved treatment. The current crop of companies going after the liver condition includes Chemomab Therapeutics, Dr. Falk Pharma, Escient Pharmaceuticals, HighTide Therapeutics and Mirum Pharmaceuticals.