CDK2 inhibitors for protecting hearing loss
Ting Therapeutics LLC is a pharmaceutical company developing drugs to prevent and treat hearing loss.
Cisplatin is one of the most widely used drugs to treat cancers. However cisplatin anticancer therapy causes
high frequency hearing loss in 40-60% of the patients. To date, no drugs have been approved by the Food and
Drug Administration for protection from cisplatin-induced hearing loss. Most candidate compounds currently in
pre-clinical and clinical trials are related to antioxidants, vitamins, and glutathione metabolism, and thus many of
these compounds, such as sodium thiosulfate, can interfere with cisplatin’s ability to kill the tumor cells. We
recently conducted unbiased high-throughput screens of bioactive compounds in a cochlear ear cell line and
identified cyclin dependent kinase-2 (CDK2) inhibitors as important therapeutic compounds for cisplatin-induced
cell death and hearing loss. Among those compounds, TT001 was the most potent CDK2 inhibitor tested. Results
from our SBIR Phase I, demonstrated that oral TT001 ameliorated cisplatin-induced hearing loss with no general
toxicity. Moreover, TT001 did not interfere with cisplatin anti-cancer activity in vitro. In this SBIR Phase II, we will
perform Investigational New Drug-enabling experiments to test TT001’s effect on cisplatin’s tumor killing efficacy
in vivo and to conduct efficacy studies to define an optimal dosing regimen and therapeutic index. The long-term
goal is for TT001 to become a standard otoprotective drug of cisplatin-based therapies. For this purpose, we will
demonstrate TT001’s efficacy in a mouse model of cisplatin ototoxicity that mimics the administration protocol in
cancer patients (Aim1). We will determine pharmacokinetics and pharmacodynamics profiles in blood and
perilymph, as well as efficacy, in a guinea pig model for cisplatin-induced hearing loss (Aim 2). This Aim will be
performed under contract with and independent and reputable Contract Research Organization, Turner Scientific
LLC. Finally, we will verify that TT001 does not interfere with cisplatin’s anti-cancer activity in vivo in mouse
model xenografts (Aim 3). By successfully completing these studies, Ting Therapeutics will obtain critical data
necessary for the initiation of Investigational New Drug-enabling Good Laboratory Practice complaint studies
and clinical trials. Ting Therapeutics LLC has the exclusive international rights for the use of CDK2 inhibitors in
the treatment of hearing loss. The company has filed for international patents in Japan, Europe, China and Hong
Kong. The patent in Europe and China has been awarded; similar patent applications are pending in US, Japan
(No 2020-156803), and Hong Kong. Ting Therapeutics is negotiating with St. Jude Children’s Research Hospital
for the US Method of Use patent rights on CDK2 inhibitors for hearing loss (US Patent Application No.
62/181,755; PCT/US16/38384; WO 2016/205806). The completion of this proposal will allow Ting Therapeutics
to initiate conversations with pharmaceutical companies for the manufacturing and licensing of TT001.