A high dose of an experimental Pliant Therapeutics medicine helped improve lung function in a small trial of people with idiopathic pulmonary fibrosis, a finding that sent the young drugmaker’s shares near record highs Monday.
The new results, released Sunday, come from a Phase 2 trial meant to test the safety of Pliant’s drug, bexotegrast, over 12 weeks. Last July, Pliant disclosed that three lower doses of bexotegrast were safe and improved an indicator of lung health that measures how much air a person can breathe out. On Sunday, Pliant said a higher dose appeared more potent with a similar safety profile.
The benefits on lung function “look even more pronounced” than what Pliant revealed previously, wrote RBC Capital Markets analyst Brian Abrahams in a note to clients. The results “should substantially de-risk later-stage studies,” he added.
Pliant shares surged 56%, to more than $35 apiece, at market open Monday. The company went public at $16 per share in 2020.
Pliant’s treatment is closely watched by analysts and investors because of its potential in idiopathic pulmonary fibrosis, or IPF, a rare lung condition that’s proven an elusive target for drugmakers.
Though two drugs, Roche’s Esbriet and Boehringer Ingelheim’s Ofev, are approved, neither are cures. Several other drugs have failed in clinical testing. That’s left an opening for companies like Pliant, whose drug interferes with a protein implicated in the formation of scar tissue.
Success could yield a blockbuster drug, as both Esbriet and Ofev have become. Stifel analyst Alex Thompson estimated the market opportunity for IPF drugs is worth more than $4 billion worldwide. Abrahams added that “successful late-stage IPF companies” have garnered valuations of over $8 billion.
Pliant’s Phase 2 trial is testing four doses of bexotegrast or a placebo in 120 IPF patients over the course of 12 weeks. About 80% of them were already taking Ofev or Esbriet.
The new results come from a group of 21 patients who received a 320 milligram dose. While the study wasn’t primarily designed to gauge the drug’s effectiveness, Pliant still evaluated the treatment’s impact on forced vital capacity, or FVC, a key measure of lung function and a standard study goal in pulmonary fibrosis. FVC improved by an average of 29.5 milliliters in patients who received the high dose, compared to a mean decline of 110 milliliters in those who got placebo.
The FVC improvements met the threshold for statistical significance at all tested timepoints, and no patients experienced more than a 10% decline in lung function, a key secondary study goal, Pliant said.
There were no drug-related severe or serious adverse events. One patient died of acute respiratory failure, but investigators determined the case was unrelated to Pliant’s drug, according to a note from SVB Securities analyst Mike Kratky. Side effects were mostly mild to moderate, with diarrhea the most common.
In Kratky’s view, the findings suggest Pliant’s drug can compete for a “best-in-class profile” in IPF.
There are still questions ahead, however. Pliant is moving the drug into larger and longer studies, where other would-be drugs have struggled. (A Phase 2b study will begin later this year.) Some investors have also questioned the magnitude of the drug’s benefit, as well as whether efficacy might wane with time, Abrahams, of RBC, wrote. The high dose had its biggest effect on lung function after four weeks and declined afterwards, according to Pliant’s press release.
“While we expect there will be continued debate on the small N and magnitude of these changes, we think that these data represent another supportive piece of the … puzzle” ahead of larger and longer studies, Stifel analyst Thompson wrote.