SEATTLE, WASHINGTON — Sound Pharmaceuticals announced today that its pivotal Phase 3 clinical trial evaluating SPI-1005, a novel anti-inflammatory compound (ebselen), for the treatment of Meniere’s Disease (STOPMD-3) successfully met its co-primary efficacy endpoints. These results demonstrate significant improvements in hearing loss and speech discrimination. Meniere’s disease (MD) is an inner ear disorder that causes fluctuating hearing loss, tinnitus, and episodic vertigo or dizziness.
Currently, there are no FDA-approved medical treatments for MD or related symptoms such as hearing loss, tinnitus, vertigo, or dizziness. SPI-1005, an oral capsule containing 200 mg ebselen, has shown safety and efficacy across multiple Phase 2 trials for MD and other hearing loss and tinnitus indications.
Phase 3 Trial Achieves Key Milestones
The STOPMD-3 trial enrolled 221 adult subjects with definite MD and active symptoms into a randomized, double-blind, placebo-controlled study. Participants received either SPI-1005 (400 mg twice daily) or placebo for 28 days, followed by monthly auditory and vestibular assessments for 84 days. Compliant patients were offered the opportunity to continue in an open-label extension (OLE) of SPI-1005 treatment for up to 12 months, with assessments every three months.
Results from both intent-to-treat and per-protocol analyses demonstrated that the SPI-1005 group had significantly higher improvement rates in low-frequency hearing loss (≥10 dB gain at one low frequency) using pure-tone audiometry (LFPTA) and speech discrimination (≥4-word increase) using the words-in-noise (WIN) test compared to the placebo group at days 28, 56, and 84.
- At day 84, 57.9% of SPI-1005 participants achieved LFPTA improvement versus 36.5% in the placebo group (58.6% improvement over placebo; p=0.0037).
- When the LFPTA criteria were increased to a ≥10 dB gain at two adjacent low frequencies, SPI-1005 participants showed a 204.4% improvement over placebo (41.1% vs. 13.5%; p<0.0001).
- WIN scores improved by 54.4% in the SPI-1005 group (42.1% vs. 27.1%; p=0.0336).
During OLE, responder rates for LFPTA and WIN continued to improve, and patient-reported outcomes for tinnitus, vertigo, aural fullness, and dizziness showed significant improvements from baseline (≥30% on average; p<0.001).
“We would like to thank all of our investigators and study participants for contributing to this pivotal Phase 3 trial success involving SPI-1005,” said Dr. Jonathan Kil, MD, CEO of Sound Pharmaceuticals.
Future Directions and Clinical Significance
A full presentation of the RCT/OLE data analysis and additional post-hoc analysis is planned for the Association for Research in Otolaryngology Midwinter Meeting in Orlando, FL, from February 22–26.
About Meniere’s Disease (MD)
Meniere’s disease is characterized by episodic vertigo, fluctuating low-frequency hearing loss, intermittent or constant tinnitus, and sometimes aural fullness. The condition often affects individuals aged 40–65, typically involving one ear. Over time, hearing loss and tinnitus can worsen, leading to severe sensory deficits. Current management strategies, including low-salt diets, diuretics, and steroid treatments, are not FDA-approved and have shown limited efficacy.
About SPI-1005
SPI-1005 is an investigational oral drug containing ebselen, a compound that mimics and induces glutathione peroxidase (GPx) activity, reducing neuroinflammation. GPx is essential for maintaining cellular health in tissues such as the inner ear, retina, brain, lungs, and kidneys. SPI-1005 is being developed for neurotologic indications, including noise-induced hearing loss and ototoxicity caused by aminoglycosides or platinum-based chemotherapy.
About Sound Pharmaceuticals
A privately-held biotechnology company is testing SPI-1005 under five other active Investigational New Drug Applications involving several neurotologic indications including the prevention and treatment of aminoglycoside-induced ototoxicity co-funded by the CF Foundation and hearing preservation in cochlear implant patients co-funded by MED-EL. Details of the SPI-1005 clinical trials can be viewed online at www.clinicaltrials.gov or www.soundpharma.com.
