Bronchiolitis obliterans syndrome (BOS) occurs in 50% of patients who endure a lung transplant. In essence, the patient’s immune system attacks the bronchioles in the new lung, causing blockages. This condition is one of the main reasons lung transplant patients often have the poorest outcomes of any form of transplant. Rates of lung transplant survival have improved in recent years thanks to perioperative management as well as advanced surgical techniques however it is still well below transplants of other organs.
BOS is estimated to affect over 30,000 patients worldwide who have either undergone a lung transplant or a stem cell transplant. Researchers relate a BOS diagnosis to the diagnosis of a severe cancer in terms of outcomes. Unfortunately, there is currently no cure for the condition and it ultimately results in respiratory failure.
Breath Therapeutics has been researching the effect of cyclosporine A (an immunosuppressant otherwise known as L-CsA-i) on BOS. This drug was first introduced during the 1980s but toxicity issues with the medication soon came to light. Breath has now created an inhaled formulation of the drug that they believe will be more effective. This formulation is delivered directly to the lungs, reducing the risk of toxicity.
The company is confident that this repurposed drug could become the very first treatment for BOS that is both safe and effective. L-CsA-i has already been given Orphan Drug Designation for this condition by both the FDA and the EMA.
Two Phase 3 clinical trials are now in the works for this new therapy.
Phase 3 Trials
Breath is conducting two Phase 3 trials so that they can evaluate the therapy in both individuals who have received a double lung transplant as well as individuals who have only received a single lung transplant. These trials are title BOSTON-2 and BOSTON-1 respectively.
Both of these investigations will include 110 patients and will last 48 weeks. Participants will span 8 countries and all will be eligible to participate in the BOSTON-3 study following their trials completion.
Researchers expect data from these two Phase 3 trials by 2021.
Also important to note, Breath has announced that they plan to initiate pediatric trials of the therapy in the United States and Europe.
These new trials are extremely exciting and are bringing a new hope to this patient population with a high unmet need.
You can read more about these investigations here.