['chronic obstructive pulmonary disease, copd', 'low peak inspiratory flow rate (pifr)']
['revefenacin', 'placebo for revefenacin', 'placebo for spiriva handihaler®']

        Inclusion Criteria:

          -  Subject is a male or female subject 40 years of age or older with a diagnosis of COPD.

          -  Subject has a current or past cigarette smoking history (or equivalent for cigar or
             pipe smoking history) of at least 10 pack-years.

          -  Subject is willing and able to provide signed and dated written informed consent to
             participate prior to initiation of any study related procedures.

        Exclusion Criteria:

          -  Subject has a concurrent disease or condition that, in the opinion of the
             investigator, would interfere with continued study participation or confound the
             evaluation of safety and tolerability of the study drug.

          -  Subject has a history of reactions or hypersensitivity to inhaled or nebulized
             anticholinergics.

          -  Subject suffers from any medical condition that would preclude the use of inhaled
             anticholinergics, including narrow-angle glaucoma, symptomatic benign prostatic
             hyperplasia, bladder neck obstruction, or urinary retention.
      