Open Access Highly Accessed Research article

Topical insulin-like growth factor 1 treatment using gelatin hydrogels for glucocorticoid-resistant sudden sensorineural hearing loss: a prospective clinical trial

Takayuki Nakagawa1*, Tatsunori Sakamoto1, Harukazu Hiraumi1, Yayoi S Kikkawa12, Norio Yamamoto1, Kiyomi Hamaguchi1, Kazuya Ono13, Masaya Yamamoto4, Yasuhiko Tabata4, Satoshi Teramukai5, Shiro Tanaka5, Harue Tada5, Rie Onodera6, Atsushi Yonezawa7, Ken-ichi Inui7 and Juichi Ito1

Author Affiliations

1 Department of Otolaryngology, Head and Neck Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan

2 Department of Otolaryngology, Faculty of Medicine, University of Tokyo, Tokyo, Japan

3 RIKEN Center for Developmental Biology, Kobe, Japan

4 Department of Biomaterials, Institute for Frontier Medical Sciences, Kyoto University, Kyoto, Japan

5 Department of Clinical Trial Design & Management, Translational Research Center, Kyoto University Hospital, Kyoto, Japan

6 Collaboration Center for Community and Industry, Sapporo Medical University, Sapporo, Japan

7 Department of Pharmacy, Kyoto University Hospital, Kyoto, Japan

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BMC Medicine 2010, 8:76  doi:10.1186/1741-7015-8-76

Published: 25 November 2010



Sudden sensorineural hearing loss (SSHL) is a common condition in which patients lose the hearing in one ear within 3 days. Systemic glucocorticoid treatments have been used as standard therapy for SSHL; however, about 20% of patients do not respond. We tested the safety and efficacy of topical insulin-like growth factor 1 (IGF1) application using gelatin hydrogels as a treatment for SSHL.


Patients with SSHL that showed no recovery to systemic glucocorticoid administration were recruited. We applied gelatin hydrogels, impregnated with recombinant human IGF1, into the middle ear. The primary outcome measure was the proportion of patients showing hearing improvement 12 weeks after the test treatment. The secondary outcome measures were the proportion of patients showing improvement at 24 weeks and the incidence of adverse events. The null hypothesis was that 33% of patients would show hearing improvement, as was reported for a historical control after hyperbaric oxygen therapy.


In total, 25 patients received the test treatment at a median of 23 days (range 15-32) after the onset of SSHL, between 2007 and 2009. At 12 weeks after the test treatment, 48% (95% CI 28% to 69%; P = 0.086) of patients showed hearing improvement, and the proportion increased to 56% (95% CI 35% to 76%; P = 0.015) at 24 weeks. No serious adverse events were observed.


Topical IGF1 application using gelatin hydrogels is well tolerated and may be efficacious for hearing recovery in patients with SSHL that is resistant to systemic glucocorticoids.