Inclusion Criteria

• Ability to provide informed consent.
  • Pediatric patients must provide assent in addition to their parents’/guardians’ consent.
• Age ≥ 12 years.
• Vestibular schwannoma categorized by * AND **

* NF2-associated OR sporadic

** Newly diagnosed within the last two years OR growing (tumor will be considered growing if it has shown ≥ 2mm increase in any dimension between scans at least 6 months apart).

• Confirmed radiographic diagnosis of vestibular schwannoma by an MRI scan with contrast. Image must be present at baseline.
• Ability to swallow capsules.

Exclusion Criteria:

• Use of aspirin (or aspirin containing products) more than four times in a single week within the last two months is exclusionary. However, patients may be eligible if they complete a 60-day washout period from aspirin.
• Use of systemic steroids or non-steroidal anti-inflammatory drugs (NSAIDs more than four times in a single week in the last two months is exclusionary.  Patients may be eligible if they complete a 60-day washout period from NSAIDs and steroids.
• Refusal to refrain from the use of aspirin, aspirin containing products, NSAIDs, and steroids throughout the course of the study  Refer to Appendix IV “Common Medications Containing Aspirin” below.
• Chronic anticoagulation with agents such as Coumadin, Pradaxa, Xarelto, Apixaban, Eliquis, Plavix, Angiomax, Argatroban, Iprivask, Heparin, Lovenox, Fragmin, Innohep, Fraxiparine, Arixtra, etc.
• Prior treatment for vestibular schwannoma as follows:
  • Radiation to target lesion. For patients with bilateral vestibular schwannomas of which only one has been irradiated, patients will be eligible if the tumor on the non-irradiated side is designated the target lesion;
  • Avastin  (bevacizumab) within 60 days prior to enrollment. Patients who have more than 60 day washout period are eligible;
  • Surgical resection of target lesion within 6 months prior to enrollment. Patients with prior surgical resection of the target lesion must have a post-op scan that shows residual tumor in order to be eligible. For patients with bilateral vestibular schwannomas of which only one has been resected, patients will be eligible if the tumor on the non-resected side is designated the target lesion.
• Known allergy to aspirin.
• Impairment of gastrointestinal function or gastrointestinal disease present in the medical history or reported by patient that may significantly alter the absorption of aspirin.
• In the opinion of the investigator, the patient is at an increased risk of gastrointestinal bleeding, for any reason.
• Pregnant or lactating women.
• Patients with serious medical illnesses (e.g. severe asthma) that in the option of the investigator could prevent participation in the trial.
• Active bleeding diathesis.
• Hydrocephalus from brainstem compression.
• History of febrile or flu-like illness in children and adolescents less than 18 years of age when taking aspirin.

Eligibility last updated 3/1/22. Questions regarding updates should be directed to the study team contact.