What is SENS-401?

A first-in-class drug to treat Sudden SensoriNeural Hearing Loss (SSNHL):

  • To protect against inner ear lesions that lead to nerve degeneration and hair cells loss
  • Received Orphan Drug Designation in Europe for treating SSNHL

R-azasetron besylate (an enantiomer of Serotone® marketed in Asia for chemotherapy-induced nausea and vomiting).

A 5-HT3 receptor antagonist and calcineurin inhibitor.

Small molecule administered orally or by injection.

Preclinical and Clinical Data

Positive preclinical and early clinical data paved the way for initiating further clinical evaluation.
  • Potent capacity to reduce hearing loss in preclinical studies
  • Good inner ear exposure after systemic administration in preclinical studies
  • A phase 1 trial showed good tolerance and confirmed pharmacokinetics at higher doses than those usually prescribed with R/S azasetron [Clinicaltrials.gov/SENS-401]

A phase 2 study is initated in Europe.


About Sudden SensoriNeural Hearing Loss (SSNHL)

SSNHL is also known as sudden deafness and belongs to the group of rare conditions that affect the inner ear

  • Rapid (instant or in <72 hours) hearing loss typically unilateral
  • Loss of >30 decibels (a 1000-fold reduction of sound perception)
  • Often accompanied by tinnitus and vertigo
  • Most commonly affects people over 45 years of age

SSNHL occurs with the destruction of sensory hair cells (sound detectors), the sensory neurons (conducting auditory information to the brain), or their connections.

While the cause of most cases (71%) in unknown (idiopathic), other possible causes include

  • Infectious (12.8%) or otologic (4.7%) diseases
  • Traumatic injury including noise (4.2%)
  • Vascular/hematologic (2.8%)
  • Neoplasia (2.3%)
  • Other (2.2%)

No treatments are currently available for SSNHL


SENS-401 and its therapeutic area are protected by several patent families.


Stachler et al., (2012). Clinical practice guideline: sudden hearing loss. Otolaryngol Head Neck Surg. 146(3 Suppl):S1-35. Pubmed

Latest news

  • 07 Jan 2021

    Sensorion announces initiation of coverage by investment banks Jefferies and Kempen with a “Buy” recommendation. Read

  • 05 Jan 2021

    Sensorion provides an update on plans and progress in the development of SENS-401 for the prevention of hearing loss. Read

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