Lung Therapeutics raises $36M to trial pleural effusion drug

Lung Therapeutics has raised a $36 million series C round to take a treatment for a serious complication of pneumonia through phase 2 studies.

Texas-based Lung Therapeutics is built on the research of Steven Idell, a pulmonologist who worked on acute lung injury and pleural diseases for decades before co-founding the biotech. Idell set up the company to advance programs based on his research into the role the fibrinolytic system plays in the pathogenesis of lung and pleural diseases.

Lung Therapeutics’ lead program, LTI-01, grew out of Idell’s work. The candidate is designed to treat pleural effusions, a complication of pneumonia that is characterized by the buildup of fluid in the gap between the lung and its lining. In some cases, fibrotic scar tissue makes it impossible to remove the fluid using drainage tubes, leading physicians to surgically remove the scar tissue.

Other physicians have explored the use of clot-busting drugs such as tissue plasminogen activator to clear the blockages without surgery. But these efforts are yet to lead to a FDA approval and, as Lung Therapeutics sees it, carry significant bleeding side effect risks.

LTI-01, a single-chain urokinase plasminogen activator, is designed to deliver the efficacy without the risks. As LTI-01 is a proenzyme, Lung Therapeutics thinks it will slowly be activated in the pleural space and will therefore enable fluid to drain without causing significant bleeding. 

Lung Therapeutics filed to start testing that hypothesis in a dose-escalation trial in 2016. Across 14 people, Lung Therapeutics saw no bleeding, treatment-emergent adverse events or surgical referrals. With decreased pleural opacity in 13 of the subjects offering a hint at the efficacy of LTI-01, Lung Therapeutics is planning to run a phase 2 trial. 

The series C, which brings the total raised by the biotech up to $53 million, will fund the phase 2 trial to completion and leave enough left over for a phase 1 study of a second drug, LTI-03. Lung Therapeutics is developing the antifibrotic peptide as a treatment for idiopathic pulmonary fibrosis.