ATOMIC Ears: A Phase IIB randomised controlled trial to assess safety, tolerability and acceptability of a 5-day Dornase alfa treatment as an adjunct therapy to ventilation tube insertion for otitis media in children

Participants will be randomised 1:1 to Dornase alfa or placebo (normal saline). Administration will be blinded. 1. Pulmozyme® solution containing 1.0 mg/mL recombinant human deoxyribonuclease I (Dornase alfa). The first dose of Dornase alfa will be administered intra-operatively. The participant’s Ear Nose and Throat (ENT) surgeon will administer 0.5mL of Dornase alfa into the participant’s ear/s intra-operatively following ventilation tube (VT) insertion. This may be unilateral if only a single VT is inserted or bilateral if a VT is inserted in both ears. Post-operatively the participant’s parent/legal guardian will administer an additional 10 doses of Dornase alfa. The dosing regimen will be 5 drops twice daily (intra-auricular) for all participants, commencing on the first evening post-Ventilation tube insertion (day 0) until the final dose is administered during the morning of the fifth post-operative day (day 5). A minimum period of 4 hours must be observed between the intra-operative dose of Dornase alfa and the first post-operative dose. The intra-operative dose administered by the participant's ENT surgeon will be documented in the participant's hospital medication record and also documented by the study staff on a centrally maintained master log. To monitor compliance with parental administration of Dornase alfa the clinical trials pharmacist will record the weight of the filled ear dropper bottle when it is dispensed and again when it is returned to pharmacy post-visit 2 (day 14). Parents/legal guardians will also be asked to complete a “study medication administration card” each time they administer the Dornase alfa, which will include the time of each dose. If a dose is missed or is not administered as per the administration instructions (5 drops) this will also be noted by the parent/ legal guardian on the “study medication administration card”. 2. All participants allocated to the Dornase alfa group will also receive Ciloxan (Ciprofloxacin) 0.3% ear drops, as per standard medical practice post-ventilation tube insertion. Parents will be advised to wait at least 10 minutes between administering the Dornase alfa (first) and the ciprofloxacin ear drops (second). Parents/legal guardians will also be asked to complete the “study medication administration card” each time they administer the ciprofloxacin ear drops.