The study is being terminated early as a result of the coronavirus (COVID-19) outbreak.

This study tests the effects of an experimental drug PC945 in people with asthma or other chronic respiratory diseases whose lungs are infected by Aspergillus fungi and Candida yeasts.

PC945 may be useful in treating patients infected with Aspergillus as, unlike the usual treatments, it is inhaled into the lung and has been designed to stay there and treat the infection. Participants will continue to receive their usual treatment for their chronic respiratory disease. Half of the participants will receive PC945 and half will receive a placebo. The amount of fungus and yeast in the patients' phlegm will be measured over the course of the study. The study will take place at multiple sites in UK and will include approximately 46 participants. The maximum study duration will be about 16 weeks.

Inclusion Criteria:

1. Subject must be male or female, aged 18 years (inclusive) or older (at the time of consent).

2. Each subject must sign an informed consent form (ICF) indicating that he or she understands the purpose and requirements of the study and is willing to participate.

3. Subject's diagnosis of moderate to severe asthma (GINA Step 3 or 4) made by a respiratory physician and treated with an inhaled steroid or other chronic respiratory disease.

   1. For subjects with asthma, the diagnosis of asthma must be supported either by:

      • i. Historical evidence of:

        • 1. Increased airway hyper-responsiveness (methacholine PC20 <8 mg/ml).
        • or
        • 2. Airflow obstruction (FEV1/FVC ratio of less than 70%) and short-term variations in FEV1 (>12%).

      • or

      • ii. Bronchodilator reversibility ≥12% or ≥200 mL improvement in FEV1 post bronchodilator after administration of a short-acting beta agonist at screening.

      OR

   2. Subjects with other chronic respiratory disease (such as COPD or bronchiectasis) susceptible to fungal bronchitis.

4. Subject must have a positive sputum fungal culture with one or more colonies of A. fumigatus complex / A. niger complex or 200 or more colonies of yeast measured using a modified standard approach on one occasion obtained within the 28-day screening period.

5. Subject must be able to produce a spontaneous sputum sample.

Exclusion Criteria:

1. Subjects who have received more than 2 weeks of intravenous (IV), oral or inhaled antifungal therapy within 6 months prior to Visit 3 or any antifungal therapy (IV, oral or inhaled) within 2 months of Visit 3.
2. Subjects taking medication that could significantly increase the risks of AEs with triazoles.
3. Subjects who are receiving antiretroviral protease inhibitors.
4. Clinical or laboratory evidence of bacterial bronchitis at the point of screening.
5. Subjects who have used an experimental medical device or received an experimental drug within 3 months or within a period less than five times the experimental drug's half-life, whichever is longer, before the first dose of the study drug is scheduled.
6. Clinically significant screening abnormalities (including, but not limited to, vital signs, ECG, laboratory tests, physical examination and spirometry) that, in the Investigator's opinion, exclude the subject from participation in the study.
7. Positive test at screening for hepatitis B virus infection, or antibodies to hepatitis C virus.
8. If female, the subject is pregnant (e.g. has a positive serum β human chorionic gonadotropin at screening or a positive urinary pregnancy test pre-dose on Day 1), lactating or breast feeding.
9. Subject is an employee or a first-degree relative of anyone employed by Pulmocide, a participating clinical trial site, or any contract research organisation involved in the study.
10. Any other reason that the Investigator considers makes the subject unsuitable to participate.

This is a double-blind study.