Table of Contents
- What is Brensocatib?
- How Does Brensocatib Work?
- Medical Conditions Being Treated with Brensocatib
- Dosage Forms Available
- Overview of Clinical Studies
- Safety and Potential Side Effects
- Special Considerations
- Ongoing Research
What is Brensocatib?
Brensocatib (also known as INS1007 or AZD7986) is an investigational medication being developed for various inflammatory conditions [1]. It is not yet fully approved for widespread use, but is currently undergoing extensive clinical testing to determine its effectiveness and safety for several medical conditions. Brensocatib is being studied primarily as an oral medication (taken by mouth) that works differently from many existing treatments by targeting a specific enzyme in the body [2].
How Does Brensocatib Work?
Brensocatib works through a unique mechanism of action. It is a selective, competitive, and reversible inhibitor of an enzyme called dipeptidyl peptidase 1 (DPP1, also known as cathepsin C) [3]. This enzyme plays an important role in activating certain proteins called neutrophil serine proteases during the maturation of neutrophils (a type of white blood cell) in the bone marrow.
When Brensocatib blocks DPP1, it prevents the activation of neutrophil proteases like neutrophil elastase, proteinase-3, and cathepsin-G. These proteases are normally released by neutrophils during inflammation and can cause tissue damage. By reducing the activity of these proteases, Brensocatib aims to decrease inflammation and tissue damage in various inflammatory conditions [4].
Unlike many anti-inflammatory treatments that work immediately, Brensocatib takes some time to show its full effect. This is because it needs time to replace the existing neutrophils with new ones that have lower levels of active proteases. Clinical studies have shown that significant reductions in neutrophil elastase concentrations can be observed after 14 days of treatment, with even greater reductions after 28 days [3].
Medical Conditions Being Treated with Brensocatib
Non-Cystic Fibrosis Bronchiectasis (NCFBE)
The most advanced research on Brensocatib is for the treatment of non-cystic fibrosis bronchiectasis (NCFBE). Bronchiectasis is a chronic condition where the airways in the lungs become damaged and widened, leading to symptoms such as chronic cough, excessive mucus production, and recurring lung infections [2].
In a Phase 2 clinical trial known as the WILLOW study, Brensocatib showed promising results in reducing the rate of pulmonary exacerbations (sudden worsening of symptoms) in people with NCFBE over a 24-week treatment period. This study tested doses of 10 mg and 25 mg once daily [2].
The research has progressed to Phase 3 with the ASPEN study, which is evaluating the effects of Brensocatib (10 mg and 25 mg) compared to placebo over a 52-week treatment period. This study is measuring how Brensocatib affects the rate of pulmonary exacerbations, lung function, and quality of life in NCFBE patients [5].
Cystic Fibrosis
Brensocatib is also being studied for potential benefits in people with cystic fibrosis, a genetic disorder that affects the lungs and digestive system. A Phase 2a study is evaluating the safety, tolerability, and pharmacokinetics (how the drug moves through the body) of Brensocatib in adults with cystic fibrosis at doses of 10 mg, 25 mg, 40 mg, and potentially 65 mg [6].
COVID-19
During the COVID-19 pandemic, Brensocatib was studied as a potential treatment for severe COVID-19. The STOP-COVID19 trial investigated whether Brensocatib could reduce the incidence of acute lung injury and acute respiratory distress syndrome (ARDS) in hospitalized COVID-19 patients by blocking damaging neutrophil proteases [3].
Hidradenitis Suppurativa
More recently, Brensocatib is being evaluated for hidradenitis suppurativa, a chronic inflammatory skin condition that causes painful bumps under the skin in areas where skin rubs together. The CEDAR study is a Phase 2b trial evaluating the efficacy and safety of Brensocatib at doses of 10 mg and 40 mg in adults with moderate to severe hidradenitis suppurativa [7].
Chronic Rhinosinusitis Without Nasal Polyps
Brensocatib is being studied for chronic rhinosinusitis without nasal polyps (CRSsNP), a condition characterized by inflammation of the sinuses that lasts 12 weeks or longer. The BiRCh study is examining whether Brensocatib (10 mg and 40 mg) can improve clinical symptoms of CRSsNP when used alongside mometasone furoate nasal spray [8].
Dosage Forms Available
Based on the clinical trials, Brensocatib is being developed in several dosage forms:
- Oral tablets: Most studies are using film-coated tablets at doses of 10 mg, 25 mg, or 40 mg taken once daily [5] [7].
- Oral solution: A pediatric oral solution is being developed and compared to the tablet form in bioavailability studies [9].
- Different oral liquid formulations: Studies are evaluating the palatability (taste) and acceptability of different Brensocatib oral liquid formulations [1].
Overview of Clinical Studies
Brensocatib is undergoing extensive clinical testing to evaluate its effectiveness, safety, and how it works in the body:
Efficacy Studies
- WILLOW Study: A completed Phase 2 study in NCFBE that showed Brensocatib could extend the time to first pulmonary exacerbation and reduce the frequency of exacerbations [2].
- ASPEN Study: An ongoing Phase 3 study in NCFBE evaluating the effect of Brensocatib on the rate of pulmonary exacerbations over 52 weeks [5].
- CEDAR Study: A Phase 2b study in hidradenitis suppurativa evaluating whether Brensocatib can reduce the number of inflammatory nodules and abscesses [7].
- BiRCh Study: A Phase 2b study in chronic rhinosinusitis without nasal polyps measuring improvements in sinus symptoms [8].
Pharmacokinetic and Safety Studies
Several studies are investigating how Brensocatib is processed by the body and potential interactions with other medications:
- Studies in participants with kidney impairment [10]
- Studies in participants with liver impairment [11]
- Studies of drug interactions with medications like clarithromycin (an antibiotic) [12], rifampin, and esomeprazole [13]
- Studies of the absorption, metabolism, and excretion of Brensocatib [4]
- Studies evaluating potential effects on heart rhythm (QT interval) [14]
Safety and Potential Side Effects
As Brensocatib is still being investigated in clinical trials, the full safety profile and list of side effects are not yet fully established. The clinical trials mentioned are carefully monitoring for adverse events, which are any undesirable experiences associated with the use of the medication.
The safety evaluation includes monitoring:
- Number of participants who experience adverse events [5]
- Laboratory tests of blood counts, liver function, and kidney function [3]
- Specific adverse events of special interest, which in some studies include hyperkeratosis (thickening of the skin), infections, and dental complications [3]
Since Brensocatib works by affecting neutrophil function, which is important for fighting infections, researchers are carefully monitoring for any increased risk of infections in study participants.
Special Considerations
Kidney and Liver Function
Specific studies are being conducted to understand how Brensocatib affects patients with impaired kidney or liver function. These studies will help determine if dose adjustments are needed for these populations [10] [11].
Drug Interactions
Studies are investigating potential interactions between Brensocatib and other medications, particularly those that affect specific liver enzymes called CYP3A4, which are involved in processing many medications. For example, a study is looking at how clarithromycin, a strong CYP3A4 inhibitor, affects Brensocatib levels in the body [12].
Administration with Food
Some studies specify that Brensocatib should be taken before breakfast, suggesting that food might affect how the drug is absorbed [2]. However, specific recommendations will be based on the results of ongoing studies.
Ongoing Research
Brensocatib research is ongoing across multiple fronts:
- Expanding to new patient populations, including children (pediatric formulations are in development) [9] [1]
- Testing in new medical conditions
- Long-term safety and efficacy monitoring
- Investigating optimal dosing regimens
- Developing new formulations for different patient needs
An expanded access program has been established for NCFBE patients who completed the ASPEN clinical trial, allowing them continued access to Brensocatib while research continues [15].
As research progresses, more information will become available about the effectiveness and safety of Brensocatib for various conditions. Patients interested in Brensocatib should discuss with their healthcare provider whether participation in a clinical trial might be appropriate for their specific situation.


