FDA grants fast track status to novel inhaled therapy for IPF

The U.S. Food and Drug Administration (FDA) has given fast track designation to LTI-03, an inhaled therapy candidate that Rein Therapeutics is developing for idiopathic pulmonary fibrosis (IPF).

Fast track status is intended to facilitate the development and review of drugs that treat serious conditions and address unmet medical needs. It allows for more frequent interactions and written communication with the FDA throughout development, aiming to ensure that patients have access to these important medications as early as possible.

Treatments granted this designation may be eligible for the FDA’s accelerated approval and priority review programs, which can further expedite the development and review of new therapies.

“Receiving Fast Track designation for LTI-03 from the FDA marks a significant milestone for Rein, and underscores the urgent need for new treatment options that can not only halt disease progression, but also potentially support tissue repair and regeneration,” Brian Windsor, PhD, Rein’s president and CEO, said in a company press release.

Meanwhile, Rein is actively recruiting participants for a global mid-stage clinical trial, dubbed RENEW (NCT06968845), that’s testing the therapy in an estimated 120 adults with IPF. Enrollment of patients ages 40 and older is now ongoing at 36 sites in the U.S., the U.K., Poland, Germany, and Australia. Interim data from the trial are expected to be reported in the second half of the year, according to the company.

“With our Phase 2 RENEW trial well underway across five countries, we have a unique opportunity to work closely with the FDA to potentially accelerate the development and review of LTI-03,” Windsor said.

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IPF is a chronic, progressive lung disease in which scar tissue builds up in the lungs — a process called fibrosis — gradually making it harder to breathe.

LTI-03 is a novel, or first-in-class, inhaled peptide therapy derived from the biology of caveolin-1, a key regulator of fibrotic signaling. The drug is designed to inhibit lung scarring while preserving alveolar progenitor cells, which are considered critical for tissue repair and regeneration.

Inhaled therapy aims to slow lung scarring while promoting healing

The company suggests that the therapy may represent a dual-acting approach that slows fibrosis while also promoting lung healing.

LTI-03 has also been granted orphan drug status by regulators in both the U.S. and the European Union. This designation provides economic incentives to companies developing treatments for rare diseases, including a period of market exclusivity should the treatment candidate ultimately be approved.

In preclinical studies, LTI-03 reduced inflammation and scarring in lung tissue collected from IPF patients. A Phase 1b study (NCT05954988) showed that the therapy lowered markers of fibrosis in adults with newly diagnosed IPF.

To be eligible for the RENEW trial, participants must have received an IPF diagnosis within the past five years and, if applicable, remain on a stable treatment regimen. Certain lung function criteria must also be met.

Participants will be randomly assigned to receive one of two doses of LTI-03 or a placebo, twice daily, as powder-filled capsules self-administered via an inhaler.

The study’s main goal is safety, as measured by the occurrence of treatment-emergent adverse events through 24 weeks, or about six months. Lung function will be measured by assessing forced vital capacity, the amount of air someone can forcefully exhale after taking a deep breath.

Although RENEW began recruiting patients last year, the FDA temporarily put the study on hold due to undisclosed concerns. A few months later, Rein said they had addressed the concerns and the trial had resumed.

“We remain on track to achieve our near-term clinical milestones and anticipate reporting interim data from this trial in the second half of this year,” Windsor said.