8 promising respiratory companies to watch in 2025

Many respiratory diseases have a huge effect on the lungs and other parts of the respiratory system and can be caused by various factors, including infection, exposure to air pollution, or smoking tobacco. This therapeutic area is very broad and there are numerous companies working on developing innovative therapies for different types of respiratory diseases, with cystic fibrosis and idiopathic pulmonary fibrosis being among the most popular indications for biotechs. In this article, we take a look at eight respiratory disease companies advancing novel therapies in 2025. 

Arrowhead Pharmaceuticals 

• Technology: RNAi  
• Respiratory disease candidates: ARO-RAGE and ARO-MMP7
• Recent news: Collaboration with Sarepta Therapeutics that includes ARO-MMP7

Equipped with a targeted RNAi molecule platform that leverages a natural pathway to “silence” genes causing disease, Arrowhead Pharmaceuticals has several focus areas, one of which is pulmonary diseases. The company has two clinical candidates in development related to respiratory diseases – one for inflammatory pulmonary diseases and one for idiopathic pulmonary fibrosis. 

The inflammatory pulmonary disease candidate is called ARO-RAGE. It is an RNAi therapeutic targeting the receptor for advanced glycation end-products (RAGE), which is implicated as an upstream mediator of type 2 and non-type 2 inflammatory cascades and is involved in the pathogenesis of asthma and numerous inflammatory diseases. The therapy is currently being investigated in a phase 1/2 study for the treatment of asthma. In May 2024, Arrowhead presented new data demonstrating that ARO-RAGE reduced serum sRAGE (sRAGE refers to the soluble form of RAGE) by up to 88% in patients with mild to moderate asthma. 

Meanwhile, the company’s second candidate is known as ARO-MMP7 and is designed to reduce the expression of matrix metalloproteinase 7 (MMP7) in the lung as a potential treatment for idiopathic pulmonary fibrosis, as MMP7 is thought to be a key molecule in the pathogenesis of the disease. The therapy is in a phase 1/2 trial, for which patients are currently being dosed. 

Earlier this month, Arrowhead closed a global licensing and collaboration agreement with Sarepta Therapeutics, in which ARO-MMP7 is part of the deal. Under the agreement, Sarepta paid Arrowhead $500 million upfront, as well as an additional $325 million in equity investment. Arrowhead also announced a $500 million strategic financing facility last year. 

Endeavour BioMedicines

• Technology: Hedgehog inhibitor
• Respiratory disease candidate: ENV-101
• Recent news: Raised $132.5 million in series C round

Endeavor BioMedicine currently has two candidates in its pipeline, one of which is intended for the treatment of fibrotic lung disease. This is the company’s lead candidate, called ENV-101. It is what is known as a hedgehog inhibitor; hedgehog is a signaling pathway that is involved in the development of embryos in animals and in maintaining tissue health. By binding to and inhibiting a key receptor in the hedgehog pathway, ENV-101 is designed to stop the abnormal accumulation of myofibroblasts that cause fibrosis. This may resolve the excessive wound-healing process seen in idiopathic pulmonary fibrosis and progressive pulmonary fibrosis, creating the potential to reverse fibrosis and improve lung volume and function.

In May 2024, Endeavour presented results from its phase 2a trial of ENV-101, showing that it improved lung function in patients with idiopathic pulmonary fibrosis, with a 1.9% mean improvement in Forced Vital Capacity (FVC) – which assesses lung function and measures the maximum amount of air a person can let out after inhaling deeply – from baseline compared to a 1.3% decline in FVC in the placebo group. Additionally, the drug was found to reverse key measures of lung disease such as quantitative lung fibrosis (QLF) and quantitative interstitial lung disease (QILD). 

After raising $132.5 million in series C funding in April 2024 to help advance the clinical development of ENV-101, the respiratory disease company announced that the first idiopathic pulmonary fibrosis patient had been dosed in a phase 2b trial of its lead candidate in November 2024. This study will evaluate the efficacy of a range of doses of ENV-101 through 24 weeks of treatment, characterize the compound’s safety, assess its effect on patient-reported outcomes, and its effects on lung capacity and lung fibrosis as measured by chest high-resolution computed tomography (HRCT).

Enterprise Therapeutics 

• Technology: ENaC inhibitor
• Respiratory disease candidate: ETD001
• Recent news: Raised £26 million ($33.1 million) in series B round

Respiratory disease company Enterprise Therapeutics has developed a pipeline of novel low molecular weight compounds with first-in-class and best-in-class potential. Its lead candidate, called ETD001, is currently being tested as a nebulized formulation in phase 2 trials for the treatment of cystic fibrosis. 

The drug works by targeting the epithelial sodium channel (ENaC) in the cells that line the lungs and other organs part of the respiratory tract. By blocking this channel, it increases hydration and clears mucus in the tract, leading to symptom relief for cystic fibrosis patients. In July 2024, Enterprise dosed the first patient in its phase 2a trial of ETD001, aiming to deliver clinical proof-of-concept and to assess the safety profile of the candidate in the 10% of people with cystic fibrosis with the highest unmet medical need. 

ETD001 has previously demonstrated a strong safety profile in healthy participants in its phase 1 trial and has been shown to be long-acting in preclinical studies. Furthermore, the drug has been granted rare pediatric disease designation by the U.S. Food and Drug Administration (FDA), as cystic fibrosis is regarded as a serious or life-threatening disease.

In January 2024, the cystic fibrosis company closed a £26 million ($33.1 million) series B follow-on round, which allowed it to fund the phase 2a trial for ETD001. 

Insilico Medicine 

• Technology: AI-developed small molecule 
• Respiratory disease candidate: ISM001-055
• Recent news: Signed a Revolving Loan Facility of up to $100 million with HSBC

Artificial intelligence (AI) drug discovery company Insilico Medicine is focused on connecting biology, chemistry, and clinical trial analysis using next-generation AI systems. Its lead drug candidate, which was discovered and designed by AI, is an anti-fibrotic small molecule drug being evaluated in clinical trials for the treatment of idiopathic pulmonary fibrosis. 

The drug, called ISM001-055, became the first AI-discovered and AI-designed drug to enter a phase 2a clinical trial in June 2023, representing an important milestone for the industry. And, more recently, in November 2024, Insilico announced positive topline results for the candidate from this trial, as it demonstrated that ISM001-055 was safe, well-tolerated, exhibited a favorable pharmacokinetics profile, and had encouraging clinical efficacy in treating idiopathic pulmonary fibrosis as measured by improvement in FVC at 12 weeks.

Insilico has signed a number of partnership deals over the past few years, including one with Sanofi in 2022 that was worth up to $1.2 billion. Most recently, the company announced a deal with Harbour BioMed to advance AI-driven antibody discovery and development, aiming to deliver innovative therapeutic solutions for the unmet medical needs of immunology, oncology, and neuroscience. 

The company also recently signed a Revolving Loan Facility of up to $100 million with HSBC to support Insilico’s global development centered on multiple sites.

ReCode Therapeutics

• Technology: Gene therapy
• Respiratory disease candidates: RCT2100 and RCT1100
• Recent news: Partnership with Intellia Therapeutics to develop gene therapies for cystic fibrosis

Gene therapy company ReCode Therapeutics is focused on developing therapies for respiratory, central nervous system, and liver diseases. Its two most advanced candidates are for respiratory diseases – RCT2100 for cystic fibrosis and RCT1100 for primary ciliary dyskinesia (PCD), a rare and progressive genetic disorder that leads to chronic respiratory infections and loss of lung function.

RCT2100 is the company’s lead candidate and is an inhaled gene therapy intended for patients who don’t respond well to cystic fibrosis transmembrane conductance regulator (CFTR) modulators, which are typically used to treat cystic fibrosis symptoms. RCT2100 aims to address the underlying cause of cystic fibrosis to curb symptoms by delivering CFTR mRNA directly to target cells in the lungs, instructing them to produce a functional version of the CFTR protein. The first patient was dosed with the drug in a phase 1b trial in September 2024. 

Meanwhile, the respiratory disease company’s other candidate, RCT1100, is an inhaled mRNA-based therapy for PCD caused by mutations in the DNAI1 gene. In January 2024, ReCode announced that the first patient had been dosed with RCT1100 in a phase 1 study that aims to evaluate the safety and tolerability of a single ascending dose of the drug in patients with PCD. The therapy was also granted orphan drug designation by the FDA in June last year. 

ReCode Therapeutics managed to raise $260 million in a series B round at the end of 2023. Since then, it has also entered into a partnership with Intellia Therapeutics to develop novel gene therapies for cystic fibrosis. 

Sionna Therapeutics

• Technology: NBD1 stabilizers
• Respiratory disease candidates: SION-719 and SION-451
• Recent news: Closed a $219.2 million IPO

Created specifically to bring cystic fibrosis therapies to patients, Sionna Therapeutics has a pipeline of small molecule candidates designed to stabilize a tough-to-drug region of the CFTR protein, called nucleotide-binding domain 1 (NBD1), which is defective in cystic fibrosis. This is because the most common mutation in CFTR, F508del, causes NBD1 to unfold at body temperature and severely impairs CFTR function. The company ultimately aims to correct the defects caused by the F508del genetic mutation, in turn restoring CFTR function to as close to normal as possible. 

The company has two lead NBD1 stabilizer candidates currently in clinical trials: SION-719 and SION-451. In August 2024, Sionna announced the initiation of two phase 1 clinical trials for these candidates to be tested in the treatment of cystic fibrosis. Sionna is also developing a portfolio of complementary CFTR modulators targeting intracellular Loop 4 (ICL4) and transmembrane Domain 1 (TMD1) that are designed to work synergistically with its NBD1 stabilizers to improve CFTR function. 

Earlier this month, Sionna announced that it had closed a $219.2 million initial public offering (IPO), as it attempts to challenge Vertex Pharmaceuticals’ dominant cystic fibrosis business.

Verona Pharma 

• Technology: Dual PDE3/PDE4 inhibitor
• Respiratory disease drug: Ohtuvayre (ensifentrine)
• Recent news: Entered into a $650 million strategic financing agreement with Oaktree and OMERS

Verona Pharma is a leader in the area of chronic obstructive pulmonary disease (COPD), which is the third leading cause of death worldwide. Verona was established 19 years ago to unlock the potential of a drug called ensifentrine, which, after undergoing nearly 20 clinical trials in COPD, was finally approved by the FDA in June last year, marking a significant milestone for the respiratory disease company as its first commercial product. 

Ensifentrine, which is now being sold under the brand name Ohtuvayre, is a dual inhibitor of the phosphodiesterase 3 (PDE3) and phosphodiesterase 4 (PDE4) enzymes. This dual inhibition enables the inhaled therapy to combine bronchodilator and non-steroidal anti-inflammatory properties in one compound, which ultimately sets it apart as a COPD treatment, as it has the ability to both open the airways of patients and reduce inflammation. 

The drug’s approval was based on two phase 3 trials that both met their primary endpoints by showing that Ohtuvayre improved lung function. Additionally, a pooled analysis of the two studies showed that the drug reduced flare-ups through 24 weeks by 40% in patients with moderate to severe COPD. 

In May 2024, Verona announced a $650 million strategic financing agreement with Oaktree Capital Management and OMERS Life Sciences, providing the company with non-dilutive capital and additional financial flexibility ahead of its U.S. launch of ensifentrine.

Vicore Pharma 

• Technology: AT2 receptor agonist
• Respiratory disease candidate: Buloxibutid
• Recent news: Raised SEK 782 million ($71.20 million) via an oversubscribed rights issue

Vicore Pharma is rapidly advancing its experimental idiopathic pulmonary fibrosis drug, called buloxibutid, through clinical trials. This is the company’s lead clinical candidate. It is a small molecule angiotensin II type 2 receptor (AT2 receptor) agonist and works by targeting the renin-angiotensin system, which plays a role in the progression of idiopathic pulmonary fibrosis.

In May 2024, Vicor announced positive final results from its phase 2a trial of buloxibutid. The study hit both primary and secondary endpoints based on an increase in FVC by over 200 mL from baseline at 36 weeks of treatment. The therapy was also found to be safe and well tolerated with no treatment-related serious adverse events.

Following the phase 2a trial, Vicore raised SEK 782 million ($71.20 million) in October last year via an oversubscribed rights issue to help advance buloxibutid into a phase 2b trial, which is now enrolling patients. The drug was also recently granted fast track designation for idiopathic pulmonary fibrosis by the FDA.

Furthermore, buloxibutid’s licensing rights in Japan now belong to Kyoto-based Nippon Shinyaku after the two companies signed an agreement worth up to $275 million in milestones to develop and commercialize the drug in the country. 

Respiratory disease drug market set for growth

According to DelveInsight’s report, the respiratory disease drug market is estimated to grow at a compound annual growth rate (CAGR) of 5.87% during the forecast period from 2024 to 2030. The growing global prevalence of respiratory disorders is the main driver for the rising demand for drugs in this area. Factors such as escalating air pollution, heightened exposure to allergens, and greater awareness of respiratory diseases – which is leading to more diagnoses and treatment – are also contributing significantly to the expansion of the market.

With so many biotech companies working in the broad respiratory space – with a particular interest in cystic fibrosis and idiopathic pulmonary fibrosis – it is understandable that the market is likely to grow in the coming years as more and more drugs continue to receive approval.

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