For People with BOS & Family Page FAQ

Frequently Asked Questions (FAQ)

Breath Therapeutics, a Zambon company, is dedicated to developing innovative inhalation therapies to treat severe respiratory diseases. People living with rare lung diseases are at the center of everything we do. Our novel investigational drug-device combination is designed to deliver drug directly to the lungs.

Bronchiolitis obliterans syndrome (BOS), also known as obliterative bronchiolitis (OB), is a lung disease caused by inflammation that leads to scarring and narrowing of the small airways. In many cases, this condition can result in respiratory failure and death. BOS is most commonly seen in people who have had a lung transplant or allogeneic hematopoietic stem cell transplant (alloHSCT). BOS can also be associated with autoimmune diseases, lung infections, or exposure to environmental contaminants.

Currently, there are no approved treatments for BOS.  There is also no accepted or demonstrated standard-of-care for BOS.

Liposomal Cyclosporine A for Inhalation (L-CsA-i) is an investigational drug being studied to treat BOS.  Cyclosporine is a medicine that suppresses the immune system and reduces inflammation when taken by mouth or intravenously (IV).  L-CsA-i is an inhaled medicine given by a drug-specific Investigational eFlow® Technology nebulizer system (PARI Pharma GmbH). The inhaled approach allows L-CsA-i to be delivered directly to the lungs, the site of BOS.

We have five clinical studies that are currently ongoing or planned:

BOSTON-1 and BOSTON-2 are two ongoing global pivotal Phase 3 studies of adults with BOS following lung transplantation.

BOSTON‑3 is an open-label extension study for eligible study participants who complete BOSTON‑1 or BOSTON‑2

BOSTON-4 has been initiated in Germany, France and Spain for adults with BOS following alloHSCT.

BOSTON‑5 is a planned safety study in pediatric patients with BOS.

If you are interested in learning more about a clinical study, please go to as this is the easiest way to find a clinical research site near you.  You can contact the research team at the site, who will determine if you are a candidate for the study.

For more information on timelines and established centers, please see the links below.

BOSTON-1 (Single Lung Transplant) Identifier: NCT03657342

BOSTON-2 (Double Lung Transplant) Identifier: NCT03656926

BOSTON-3 (Open-label extension of BOSTON-1 and -2) Identifier: NCT04039347

BOSTON-4 (alloHSCT) Identifier: NCT04107675

Clinical studies are studies performed with people to examine new ways to prevent, detect, or treat disease. The purpose of clinical studies is to determine if a new medication or medical device works and if it is safe.  This is done before it is approved by the FDA (or equivalent) and made available for use by doctors.  With all clinical studies there may be no direct benefit to any one individual who participates in a study.

The United States Food and Drug Administration (FDA) has information on this subject.  Resources can be found via this link.

Currently, there is no compassionate use or expanded access program for L-CsA-i.

No, L-CsA-i is not an approved treatment and is only available through clinical studies.

If you have additional questions, please contact

Patient Resources:

There are many disease foundations, patient advocacy groups, and support groups at both the local and national level.  Your transplant care team can direct you to resources that are in your area.