Ascletis announces that its clinical trial application for the oral PD-L1 small molecule inhibitor ASC61 for the treatment of advanced solid tumors has been approved by the China National Food and Drug Administration

Ascletis Pharmaceuticals Limited (HKEx: 1672, "Ascletis") today announced that ASC61, an oral small molecule inhibitor of oral PD-L1, has been approved by the National Medical Products Administration (NMPA) of China (NMPA) for a New Drug Clinical Trial (IND) application for the treatment of advanced solid tumors
.
The US Phase I dose-escalation study of ASC61 is progressing in an orderly manner, and the approval of the Chinese IND will accelerate the global development
of ASC61.

ASC61 is an oral small molecule inhibitor prodrug
.
Its active metabolite, ASC61-A, is a potent and highly selective inhibitor that blocks PD-1/PD-L1 interactions
by inducing PD-L1 dimer formation and endocytosis.
ASC61 monotherapy has shown significant anti-tumor efficacy
in a variety of animal models, including humanized mouse models.
Preclinical studies have shown that ASC61 has good safety and pharmacokinetic characteristics
in animal models.

In a head-to-head comparison using human PD-L1-expressing cells and fresh peripheral blood mononuclear cells (PBMCs), ASC61-A treatment induced IFNγ secretion and exhibited a concentration-dependent half-maximal effect concentration EC50 of 2.
86 nM
.
The maximum level of IFNγ induced by ASC61-A is similar
to that induced by the marketed PD-1 antibody Keytruda.

Compared with PD-1/PD-L1 antibody injection, oral PD-L1 inhibitor ASC61 has the following advantages: (1) convenient and safe administration, no need to go to the hospital for injection, and higher patient compliance; (2) It is easy to form an all-oral combination treatment regimen with other oral antitumor drugs; (3) flexible dosing can better manage immune-related adverse events; (4) The cost is relatively lower; and (5) higher
permeability to tumor tissue.

"Poor immunogenicity and tumor tissue permeability are the main limitations of therapeutic antibodies, which can lead to low
PD-1/PD-L1 antibody response rates.
As a highly differentiated small molecule PD-L1 inhibitor, ASC61 currently shows good safety data
in dose-escalation trials in patients with advanced solid tumors in the United States.
With INDs approved in both China and the United States, we look forward to accelerating the global development of ASC61 and providing more treatment options
for patients with advanced solid tumors.
" Dr.
Jinzi Wu, Founder, Chairman of the Board and Chief Executive Officer of Ascletis, said
.