Study Investigating the Effect of 4 Doses of RPL554 Given in Addition to Tiotropium to Patients With COPD

The purpose of this study is to investigate the dose response of RPL554 in patients with moderate to severe CHRONIC OBSTRUCTIVE PULMONARY DISEASE that are still symptomatic despite treatment with a stable background of tiotropium over 4 weeks of treatment. This study is intended to support optimal dose selection for a Phase III program evaluating RPL554 as an add-on treatment to standard of care therapy.

This is a Phase IIb, randomized, double-blind, placebo controlled, multiple dose, parallel group study to investigate the effects of 4 weeks of treatment with nebulized RPL554 (at different dose levels) compared to placebo in patients with moderate to severe CHRONIC OBSTRUCTIVE PULMONARY DISEASE on a stable background therapy of open-label tiotropium. The study comprises seven visits: Pre-screening (Visit 0), Screening (Visit 1) and then a Treatment Period consisting of Randomization (Visit 2), and weekly visits for 4 weeks (Visit 3 to Visit 6).

Eligibility Criteria:
Inclusion Criteria:

* Sign an informed consent document indicating they understand the purpose of and procedures required for the study and are willing to participate in the study.
* Male or female aged between 40 and 80 years inclusive, at the time of informed consent.
* Must agree to meet the following from the first dose up to 1 month after the last dose of study medication:

  * If male:

    * Not donate sperm
    * Either: be sexually abstinent in accordance with a patient's usual and preferred lifestyle (but agree to abide by the contraception requirements below should their circumstances change)
    * Or: use a condom with all sexual partners. If the partner is of childbearing potential the condom must be used with spermicide and a second reliable form of contraception must also be used (e.g., diaphragm/cap with spermicide, established hormonal contraception, intra-uterine device)
  * If female:

    * be of non-childbearing potential or use a highly effective form of contraception
* Have a 12-lead ECG recording at Screening showing the following (and no changes in the pre-dose value at the first treatment deemed clinically significant by the Investigator):

  * Heart rate between 45 and 90 beats per minute
  * QT interval corrected for heart rate using Fridericia's formula (QTcF) ≤450 msec for males, and ≤ 470 msec for females
  * QRS interval ≤ 120 msec
  * No clinically significant abnormality including morphology (e.g., left bundle branch block, atrio-ventricular nodal dysfunction, ST segment abnormalities consistent with ischemia)
* Capable of complying with study restrictions and procedures, including ability to use the nebulizer correctly.
* Body mass index (BMI) between 18 and 35 kg/m2 (inclusive) with a minimum weight of 45 kg.
* COPD diagnosis: Patients with a diagnosis of COPD as defined by the American Thoracic Society (ATS)/European Respiratory Society (ERS) guidelines (Celli and MacNee, 2004) with symptoms compatible with COPD for at least 1 year prior to Screening.
* Ability to perform acceptable and reproducible spirometry.
* Post-bronchodilator (four puffs of albuterol) spirometry at Screening demonstrating the following:

  * FEV1/ FVC ratio of ≤0.70
  * FEV1 ≥30% and ≤70% of predicted normal\* \*National Health and Nutrition Examination Survey (NHANES) III (Hankinson et al, 1999) will be used as the reference for normal predicted values.
* Clinically stable COPD in the 4 weeks prior to Screening (Visit 1) and during the period between Visits 1 and 2.
* A score of ≥2 on the modified Medical Research Council (mMRC) dyspnea scale at Screening.
* A chest X-ray (posterior-anterior) at Screening, or in the 12 months prior to Screening showing no clinically significant abnormalities unrelated to COPD.
* Meet the concomitant medication restrictions and be expected to do so for the rest of the study.
* Current and former smokers with smoking history of ≥10 pack years.
* Capable of withdrawing from long acting bronchodilators (other than tiotropium) for the duration of the study, and short acting bronchodilators for 6 hours prior to dosing.

Exclusion Criteria:

* A history of life-threatening COPD including Intensive Care Unit admission and/or requiring intubation.
* COPD exacerbation requiring oral or parenteral steroids, or lower respiratory tract infection requiring antibiotics, within 3 months of Screening or prior to the first treatment.
* A history of one or more hospitalizations for COPD or pneumonia within 6 months of Screening or prior to the first treatment.
* Intolerance or hypersensitivity to albuterol, tiotropium or other muscarinic receptor antagonists.
* Other respiratory disorders: Patients with a current diagnosis of asthma, active tuberculosis, lung cancer, bronchiectasis, sarcoidosis, lung fibrosis, interstitial lung diseases, uncontrolled or unstable sleep apnea, known alpha-1 antitrypsin deficiency, core pulmonale, clinically significant pulmonary hypertension or other active pulmonary diseases.
* Previous lung resection or lung reduction surgery.
* Pulmonary rehabilitation, unless such treatment has been stable from 4 weeks prior to Screening and remains stable during the study.
* Oral therapies for COPD (e.g. oral steroids, theophylline, and roflumilast) or antibiotics within 3 months prior to Screening, or ICS therapy within 4 weeks prior to Screening
* Prior exposure to RPL554.
* History of, or reason to believe a patient has, drug or alcohol abuse within the past 5 years.
* Received an experimental drug within 30 days or five half-lives, whichever is longer.
* Women who are pregnant or breast-feeding.
* Patients with uncontrolled disease including, but not limited to, endocrine, active hyperthyroidism, neurological, hepatic, gastrointestinal, renal, hematological, urological, immunological, psychiatric, or ophthalmic diseases that the Investigator believes are clinically significant. This includes any hepatic disease or moderate to severe renal impairment.
* Documented clinically significant cardiovascular disease such as: any history of arrhythmias, angina, recent (\<1 year) or suspected myocardial infarction, congestive heart failure, unstable or uncontrolled hypertension, or diagnosis of hypertension within 3 months prior to Screening.
* Use of non-selective oral β-blockers.
* Major surgery (requiring general anesthesia) within 6 weeks prior to Screening, lack of full recovery from surgery at Screening, or planned surgery through the end of the study.
* Required use of oxygen therapy, even on an occasional basis.
* History of malignancy of any organ system within 5 years, with the exception of localized skin cancers (basal or squamous cell).
* Clinically significant abnormal values for laboratory safety tests (hematology, blood chemistry, viral serology or urinalysis) at Screening, as determined by the Investigator. In particular, alanine aminotransferase or aspartate aminotransferase cannot be more than twice the upper limit of normal.
* Patients with conditions which are sensitive to antimuscarinic effects such as narrow angle glaucoma, urinary retention, prostatic hypertrophy, or bladder neck obstruction.
* Current marijuana use (all forms).
* A disclosed history or one known to the Investigator, of significant non-compliance in previous investigational studies or with prescribed medications.
* Any other reason that the Investigator considers makes the patient unsuitable to participate.