Positive Results from Phase 2 WILLOW Study of Brensocatib in Patients w/ Non-cystic Fibrosis Bronchiectasis

Drug Name: brensocatib

Insmed Incorporated, a global biopharmaceutical company on a mission to transform the lives of patients with serious and rare diseases, announced that final results from the Phase 2 WILLOW study of brensocatib (formerly INS1007) in patients with non-cystic fibrosis bronchiectasis (NCFBE) were presented during a virtual American Thoracic Society (ATS) session titled Breaking News: Clinical Trial Results in Pulmonary Medicine. Brensocatib is a novel, oral, reversible inhibitor of dipeptidyl peptidase 1 (DPP1) being developed by Insmed for the treatment of bronchiectasis and other inflammatory diseases.

The WILLOW study met its primary endpoint, with brensocatib significantly prolonging time to first pulmonary exacerbation over the 24-week treatment period versus placebo (p=0.027 for the 10 mg group; p=0.044 for the 25 mg group). The risk of exacerbation at any time during the trial was reduced by 42% for the 10 mg group versus placebo (HR 0.58, p=0.029) and by 38% for the 25 mg group versus placebo (HR 0.62, p=0.046).

Treatment with brensocatib 10 mg also resulted in a significant reduction in the rate of pulmonary exacerbations, a key secondary endpoint, versus placebo. Patients treated with brensocatib experienced a 36% reduction in the 10 mg arm (p=0.041) and a 25% reduction in the 25 mg arm (p=0.167) versus placebo. Change from baseline to the end of the treatment period in the concentration of active neutrophil elastase (NE) in sputum demonstrated a significantly larger reduction with both brensocatib doses versus placebo (p=0.034 for 10 mg, p=0.021 for 25 mg).

"I am very encouraged by the results from the Phase 2 WILLOW study, which underscore the potential for brensocatib to reduce the risk of pulmonary exacerbation in patients with NCFBE," said presenter and lead study investigator James Chalmers, MBChB, Ph.D., Professor and Consultant Respiratory Physician at the School of Medicine, University of Dundee, UK. "These findings are critically important given the vicious cycle of inflammation, lung damage, and infection that patients with NCFBE face and the current lack of approved pharmaceutical therapies."

In addition to the previously reported primary and secondary endpoint data, Professor Chalmers presented new data today from a pooled analysis of patients treated with either dosage of brensocatib in the WILLOW study. This analysis showed that patients treated with brensocatib who achieved sputum NE below the limit of quantification post-baseline had a lower incidence of pulmonary exacerbations compared to patients who had a quantifiable level of sputum NE post-baseline. Importantly, the risk of having an exacerbation was 72% lower in these patients.

"We are thrilled to share positive final results from the Phase 2 WILLOW study today, confirming the top-line results presented earlier this year. These findings are very meaningful for patients with NCFBE, who currently suffer from severe outcomes in the absence of an approved therapy," said Martina Flammer, M.D., MBA, Chief Medical Officer of Insmed. "Importantly, the new data presented today demonstrate the relationship between NE reduction and risk of exacerbation and serve as further proof of concept of the potential of brensocatib and its unique mechanism of action. We look forward to initiating our Phase 3 program in bronchiectasis while also exploring the potential of brensocatib in other neutrophil-driven inflammatory conditions."

Brensocatib was generally well-tolerated in the study. Rates of adverse events (AEs) leading to discontinuation in patients treated with placebo, brensocatib 10 mg, and brensocatib 25 mg were 10.6%, 7.4%, and 6.7%, respectively. The most common AEs in patients treated with brensocatib were cough, headache, sputum increase, dyspnea, infective exacerbation of bronchiectasis, diarrhea, fatigue, and upper respiratory tract infection.

Rates of adverse events of special interest (AESIs) in patients treated with placebo, brensocatib 10 mg, and brensocatib 25 mg, respectively, were as follows: rates of skin events (including hyperkeratosis) were 11.8%, 14.8%, and 23.6%; rates of dental events were 3.5%, 16.0%, and 10.1%; and rates of infections considered AESIs were 17.6%, 13.6%, and 16.9%. Hyperkeratosis was reported in 1/85, 3/81, and 1/89 patients treated with placebo, brensocatib 10 mg, and brensocatib 25 mg, respectively. The study included extensive dental evaluations to closely monitor progression of periodontal disease. The results did not raise a signal about dental safety. The percentage of patients with change in periodontal pocket depth =2 mm and absolute value of =5 mm (the threshold of concern for periodontal disease) were 11.6%, 11.3%, and 12.3% for placebo, brensocatib 10 mg, and brensocatib 25 mg, respectively.

Brensocatib received breakthrough therapy designation from the U.S. Food and Drug Administration in June 2020 for the treatment of adult patients with NCFBE for reducing exacerbations. Insmed plans to initiate a Phase 3 program for brensocatib in bronchiectasis in the second half of 2020.

About WILLOW

WILLOW was a randomized, double-blind, placebo-controlled, parallel-group, multi-center, multi-national, Phase 2 study to assess the efficacy, safety, and tolerability, and pharmacokinetics of brensocatib administered once daily for 24 weeks in patients with non-cystic fibrosis bronchiectasis (NCFBE). WILLOW was conducted at 116 sites and enrolled 256 adult patients diagnosed with NCFBE who had at least two documented pulmonary exacerbations in the 12 months prior to screening. Patients were randomized 1:1:1 to receive either 10 mg or 25 mg of brensocatib or matching placebo. The primary efficacy endpoint was the time to first pulmonary exacerbation over the 24-week treatment period in the brensocatib arms compared to the placebo arm.

About Brensocatib (Formerly INS1007)

Brensocatib is a small molecule, oral, reversible inhibitor of dipeptidyl peptidase I (DPP1) being developed by Insmed for the treatment of patients with bronchiectasis. DPP1 is an enzyme responsible for activating neutrophil serine proteases (NSPs), such as neutrophil elastase, in neutrophils when they are formed in the bone marrow. Neutrophils are the most common type of white blood cell and play an essential role in pathogen destruction and inflammatory mediation. In chronic inflammatory lung diseases, neutrophils accumulate in the airways and result in excessive active NSPs that cause lung destruction and inflammation. Brensocatib may decrease the damaging effects of inflammatory diseases such as bronchiectasis by inhibiting DPP1 and its activation of NSPs.

SOURCE: GlobalData.com