Jascayd (nerandomilast) for idiopathic pulmonary fibrosis

Last updated Oct. 9, 2025, by Marisa Wexler, MS
Fact-checked by Joana Carvalho, PhD

What is Jascayd for idiopathic pulmonary fibrosis?

Jascayd (nerandomilast) is an approved oral therapy that’s intended to slow lung function decline in adults with idiopathic pulmonary fibrosis (IPF).

IPF is a chronic progressive disease of unknown origin marked by fibrosis (scarring) and inflammation in the lungs. It makes it harder for oxygen to reach the bloodstream, leading to symptoms that may include cough and shortness of breath.

Jascayd is designed to reduce disease-driving inflammation and fibrosis in IPF by blocking the activity of an inflammatory enzyme called phosphodiesterase 4B (PDE4B). This, in turn, is expected to help slow lung function decline.

Available as oral tablets that can be swallowed whole or dispersed in water, Jascayd is the first and only preferential inhibitor of PDE4B to be approved for this indication. It was developed by Boehringer Ingelheim. The company is also developing Jascayd as a treatment for progressive pulmonary fibrosis, which comprises lung diseases other than IPF that are marked by inflammation and fibrosis that progressively worsen over time.

Therapy snapshot

Who can take Jascayd?

Jascayd is approved in the U.S. as a treatment for adults with IPF.

While its prescribing information lists no contraindications, Jascayd should not be taken alongside medications that increase the activity of CYP3A, the enzyme that processes Jascayd in the body.

How is Jascayd administered?

Jascayd is available as 9 and 18 mg film-coated tablets. The tablets may be swallowed whole or dispersed in water.

The recommended dosage is 18 mg taken twice daily, approximately 12 hours apart, with or without food. Lower doses (9 mg twice daily) may be used for individuals who experience intolerable side effects, unless they are taking Jascayd alongside pirfenidone, an approved IPF medication sold as Esbriet, with generics also available. The same lower dose regimen is also recommended for patients taking Jascayd alongside strong CYP3A inhibitors.

Jascayd in clinical trials

Jascayd’s approval for IPF in the U.S. was based on data from two clinical trials:

• A Phase 2 study (NCT04419506), completed in 2021, tested Jascayd against a placebo in 147 adults with IPF. The results showed that, after three months, the therapy outperformed the placebo in its ability to slow the decline of forced vital capacity (FVC), a common measure of lung function that assesses how much air a person can forcibly exhale after a deep breath.
• A Phase 3 study called FIBRONEER-IPF (NCT05321069), completed in 2024, evaluated Jascayd versus a placebo in 1,177 adults with IPF, most of whom were also receiving other approved antifibrotic IPF therapies (pirfenidone or nintedanib, which is sold as Ofev). Jascayd was significantly better than the placebo at slowing FVC decline after a year of treatment, these results showed. Data also indicated that Jascayd reduced the risk of death among IPF patients. The results were generally comparable in patients who were or were not taking other IPF treatments. Participants taking pirfenidone and given the lowest 9 mg dose of Jascayd were the only ones who were not found to benefit from treatment.

Jascayd has also been tested in a Phase 3 clinical study called FIBRONEER-ILD (NCT05321082), which assessed the safety and efficacy of the therapy against a placebo in 1,176 adults with progressive forms of pulmonary fibrosis other than IPF. Similar to findings from FIBRONEER-IPF, results from this trial indicated that Jascayd was able to slow FVC decline and reduce the risk of death in these patients.

Jascayd side effects

The most common side effects of Jascayd include:

• diarrhea
• COVID-19
• upper respiratory tract infection
• depression
• weight loss
• decreased appetite
• nausea
• fatigue
• headache
• vomiting
• back pain
• dizziness

The medication’s prescribing information lists no other warnings or precautions related to the use of Jascayd.

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