In a major development for respiratory medicine, Boehringer Ingelheim announced that nerandomilast (BI 1015550), its novel PDE4B inhibitor, met the primary endpoint in the pivotal FIBRONEER-ILD Phase III trial. The therapy demonstrated a statistically significant reduction in lung function decline, measured by forced vital capacity (FVC), in patients with progressive pulmonary fibrosis (PPF) compared with placebo over a 52-week treatment period.

The results mark a potentially groundbreaking advancement for patients suffering from fibrotic lung conditions, which are often progressive, debilitating, and fatal. Currently, therapeutic options are limited, and many patients continue to face poor prognoses despite treatment.

About the FIBRONEER-ILD Study

The FIBRONEER-ILD trial was a global, randomized, double-blind, placebo-controlled study enrolling patients with progressive pulmonary fibrosis, regardless of underlying cause. The trial sought to confirm whether nerandomilast could slow the decline in lung function — the hallmark clinical measure for PPF progression.

• Primary Endpoint: Change in FVC over 52 weeks.
• Key Finding: Patients receiving nerandomilast experienced significantly less decline in lung function compared to placebo.
• Safety Profile: The drug demonstrated a favorable safety profile, with adverse events consistent with prior studies. Most were manageable, and no new safety signals emerged.

The consistency of the safety data across multiple studies strengthens the case for nerandomilast as a long-term treatment option.

How Nerandomilast Works

Nerandomilast is an oral, preferential PDE4B inhibitor, designed to target pathological inflammation and fibrosis in the lungs. PDE4B is an enzyme implicated in regulating inflammatory pathways, and its selective inhibition is believed to reduce lung scarring without the broad side effects often seen with non-selective PDE4 inhibitors.

The oral dosing format provides a significant advantage for patients compared to more invasive treatment approaches, potentially improving adherence and quality of life.

Next Steps: Toward Regulatory Approval

Boehringer Ingelheim has confirmed that, based on these positive results, it will move swiftly to file a New Drug Application (NDA) with the U.S. Food and Drug Administration (FDA), along with submissions to regulatory bodies in Europe and other key global markets.

If approved, nerandomilast could join or complement existing antifibrotic therapies such as nintedanib and pirfenidone, expanding the treatment toolbox for clinicians and patients battling PPF.

Broader Impact on Clinical Research

The FIBRONEER-ILD success highlights several important themes in clinical research today:

1. Patient-Centric Drug Development
   By focusing on a drug with oral administration, Boehringer addresses not only efficacy but also convenience — a key determinant of treatment uptake in chronic conditions.
2. Biomarker-Driven Design
   Measuring FVC remains the gold standard in pulmonary fibrosis trials, but Boehringer is also exploring biomarkers to better predict and monitor therapeutic responses.
3. Accelerated Regulatory Pathways
   Given the urgent unmet need in PPF, nerandomilast may qualify for expedited review pathways, potentially bringing a new therapy to market faster.

Expert Commentary

Respiratory experts have welcomed the results, emphasizing their potential impact:

“Progressive pulmonary fibrosis is one of the most challenging conditions we face in respiratory medicine. The FIBRONEER-ILD data suggest nerandomilast could meaningfully alter disease trajectories for many patients who currently have few options,” commented a lead investigator of the study.”

The announcement also reinforces Boehringer’s strong position in fibrosis and interstitial lung disease (ILD) research, where the company already markets Ofev (nintedanib). Nerandomilast could represent the next generation of antifibrotic therapy.

Global Context: Pulmonary Fibrosis Research

The FIBRONEER-ILD trial adds momentum to a wave of ongoing research in pulmonary fibrosis:

• Pipeline Expansion: Multiple companies are investigating novel mechanisms, from integrin inhibitors to gene therapies.
• Trial Diversification: Increasingly, trials are recruiting broader patient populations, ensuring results are more representative of real-world clinical settings.
• Collaboration: Partnerships between academia, regulators, and industry are helping accelerate trial designs, particularly in rare and high-need conditions like PPF.

The positive topline results from the FIBRONEER-ILD Phase III study position nerandomilast as a likely new entrant in the treatment landscape for progressive pulmonary fibrosis. With regulatory submissions on the horizon, patients and clinicians may soon gain access to an oral, targeted therapy that meaningfully slows disease progression — a long-awaited advance in respiratory medicine.