SPI-1005 (ebselen) for Tinnitus: What Does the Evidence Show?

Current evidence

The most advanced drug with a tinnitus-relevant claim — but its trials are in Meniere's disease, and the tinnitus data are unblinded.

Evidence strength: Limited (2/5) · Tier 3 — experimental/emerging · Evidence independence: Primarily sponsor-supported.

An oral anti-inflammatory/antioxidant (glutathione peroxidase mimetic) from Sound Pharmaceuticals, in Phase 3 for Meniere's disease with tinnitus tracked as a patient-reported outcome.

Did tinnitus loudness improve?

Limited. Company reports ≥30% patient-reported tinnitus severity improvement — from an open-label extension, so high bias risk and not a loudness measurement.

Did tinnitus distress improve?

Limited. Same open-label PRO data; no blinded tinnitus outcome has been published.

Loudness means the tinnitus percept itself became quieter (psychoacoustic matching or loudness ratings). Distress means questionnaire scores such as THI/TFI, sleep, anxiety or quality of life improved — the sound may be unchanged. A THI/TFI improvement is never evidence the tinnitus got quieter.

How strong is the evidence?

A Phase 3 program with BTD earns 2/5 for tinnitus specifically: the tinnitus outcomes are open-label, company-reported, and in a Meniere's population. The ongoing Phase 3 (NCT06859788) is open-label single-group — it cannot produce controlled tinnitus evidence.

Has the result been independently replicated?

None yet.

What are the limitations?

• No peer-reviewed Phase 3 publication yet
• Tinnitus data are open-label PROs
• Indication is Meniere's, not tinnitus

Conflicts of interest: All results to date are company press releases.

What should patients know about safety?

Safety evidence: Limited. Reported as well tolerated in trials to date (company-reported).

Is it available?

Regulatory status: Investigational (FDA Breakthrough Therapy designation — for hearing loss in Meniere's, NOT tinnitus). Breakthrough Therapy designation granted December 1, 2025 for treatment of hearing loss in Meniere's disease. STOPMD-3 results are company-reported; no peer-reviewed publication located as of Sept 2026. FDA publishes no BTD registry, so the sponsor announcement is the strongest available source.

Availability: Not available — clinical trials only · Europe: Not available · Cost (approx.): N/A

What the studies found

Related clinical trials

• SPI-1005 (ebselen) open-label Phase 3 safety study in Meniere's disease — Active, not recruiting

Tracked trials are research in progress, not recommended treatments.

Related treatments

• TRTL-913 (GABA-A modulator) — A new $106M bet that a GABA-A drug can quiet tinnitus — Phase 2 starts soon; no human tinnitus data yet.
• Intratympanic drug injections — Injections through the eardrum keep failing their controlled tests — the placebo response is doing the work.
• Off-label oral drugs (antidepressants, benzodiazepines, gabapentin, betahistine) — No drug is approved for tinnitus anywhere — and the systematic reviews say none of the usual suspects works…
• Supplements (ginkgo, zinc, melatonin…) — Heavily marketed, repeatedly tested, consistently unsupported.