Phase 1 study to evaluate safety, tolerability and pharmacokinetics of a novel intra-tympanic administered thiosulfate to prevent cisplatin-induced hearing loss in cancer patients

Invest New Drugs. 2020 Oct;38(5):1463-1471. doi: 10.1007/s10637-020-00918-1. Epub 2020 Mar 10.


Cisplatin is a widely used chemotherapy for the treatment of certain solid tumors. Ototoxicity and subsequent permanent hearing loss remain a serious dose-limiting side effect associated with cisplatin treatment. To date, no therapies have been approved to prevent or treat cisplatin-induced hearing loss (CIHL). Sodium thiosulfate effectively inactivates cisplatin through covalent binding and may provide protection against cisplatin-induced ototoxicity. DB-020 is being developed as a novel formulation of sodium thiosulfate pentahydrate in 1% sodium hyaluronate for intratympanic injection (IT), enabling the delivery of high concentrations of thiosulfate into the cochlea prior to cisplatin administration. In the DB-020-002 phase 1a single-ascending dose study, healthy volunteers were enrolled into 5 cohorts to receive different doses of DB-020 via IT injection. Cohorts 1-4 received unilateral injections while Cohort 5 received bilateral injections. Plasma thiosulfate pharmacokinetics was measured, and safety and audiometric data were collected throughout the study. This study has demonstrated that intratympanic administration of DB-020 results in nominal systemic increases in thiosulfate levels, hence it should not compromise cisplatin anti-tumor efficacy. Furthermore, DB-020 was safe and well tolerated with most adverse events reported as transient, of mild-to-moderate severity and related to the IT administration procedure. These results support the design and execution of the ongoing proof-of-concept study, DB-020-002, to assess otoprotection using DB-020 in cancer patients receiving cisplatin without negatively impacting cisplatin anti-tumor efficacy.

Keywords: Cisplatin; Hearing loss; Intratympanic; Ototoxicity.

Publication types

  • Clinical Trial, Phase I
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Antineoplastic Agents / administration & dosage*
  • Antineoplastic Agents / adverse effects
  • Antineoplastic Agents / pharmacokinetics
  • Cisplatin / administration & dosage
  • Cisplatin / adverse effects
  • Cisplatin / pharmacokinetics
  • Double-Blind Method
  • Female
  • Healthy Volunteers
  • Hearing Loss / chemically induced
  • Hearing Loss / prevention & control*
  • Humans
  • Injection, Intratympanic
  • Male
  • Middle Aged
  • Neoplasms / drug therapy
  • Neoplasms / metabolism
  • Thiosulfates / administration & dosage*
  • Thiosulfates / adverse effects
  • Thiosulfates / blood
  • Thiosulfates / pharmacokinetics
  • Young Adult


  • Antineoplastic Agents
  • Thiosulfates
  • sodium thiosulfate
  • Cisplatin