Determined not feasible

Randomized, double blind, placebo controlled study. The study has two parts:

Dose-finding part, followed by longer term follow-up (6 months)

Part 1: Randomized, double blind, placebo controlled dose-finding. Patients will be assigned to 1 of 3 doses OligoG, or to placebo, on top of Standard of Care. Patients will be treated for 12 weeks, followed by 4 weeks washout.The primary endpoint is relative change in % predicted FEV1. Secondary endpoints include additional spirometry parameters, exacerbation rate, Quality of Life, sputum rheology and microbiology, safety laboratory tests and adverse event reporting.

Part 2: Randomized double-blind 6 -month study, for longer term follow-up of the dose identified in Part 1. New patients will be recruited in part 2, in addition to patients who received placebo in Part 1. In addition to the endpoints studied in Part 1, Part 2 will include Lung Clearance Index (LCI), chest imaging by MRI or CT, and pharmaco-economic parameters.

Inclusion Criteria:

• Confirmed diagnosis of CF
• FEV1 at screening >40 and < 90% of predicted normal
• History of PA infection in last 12 m
• History of antibiotic treatment due tp PA infection (not for eradication) during last 12 m
• Concomitant inhaled tobramycin, colistin, aztreonam, or levoflaxin (cycled or continuous)
• Stable CF disease
• Willing to remain on stable CF medication (Standard of care)
• Women of child-bearing potential must habe negative urine pregnany test
• Males & females must use acceptable contraception
• Capable of inhaling dry powder
• willing to sign informed consent
• willing and able to follow study procedures

Exclusion Criteria:

• Use of hypertonic saline > twice daily
• Clinically significant abnormal lab findings, except CRP. In case of high GGT values, case will be discussed by experts before deciding
• History of comorbidity that may distort results or cause additional risk
• pulmonary exacerbation within 28 days prior to randomisation
• Change in CF therapy within 28 days prior to randomisation
• Burkholderia spp. finding within 12 m prior to screening
• pregnant or breast feeding females
• History of allergic reactions to IMP ingredients, incl milk protein
• Inability to perform lung function tests according to ATS/ ERS criteria
• Uncontrolled or unstable diseases that might limit compliance
• History of, or planned organ transplantation
• Allergic ABPA in the last 12 months prior to the screening visit
• Requirement for continuous oxygen supplementation
• Current participation in another clinical study
• medical condition, other than CFwhich exposes the patient to an unacceptably high risk
• Concurrent mlignant disease, except BCC and cervical neoplasia
• Clinically significant alcohol or drug abuse

Placebo medication with identical appearance to the active drug