Shares of CK Life Sciences International (0775) jumped up to 41 percent to HK$0.68 as trading resumed on Friday on promising early results on cancer vaccines.

The company said in a filing before market opening that it has obtained good results in laboratory tests of its preclinical stage novel cancer vaccines targeting Trophoblast Cell Surface Antigen 2.

TROP2 is a cell surface glycoprotein that is overexpressed in a wide range of cancers, including breast, lung, pancreatic and colorectal cancers, the filing said.

The company considers that TROP2 is an exciting therapeutic target, and the anti-cancer efficacy observed in mouse studies of the company’s TROP2 cancer vaccines is unprecedented, it said.

CK Life Sciences has filed an original grant patent application with the Intellectual Property Department of Hong Kong and a provisional patent application with the US Patent and Trademark Office for its circular RNA and fusion protein TROP2 cancer vaccines, the filing read.

What is TROP2?

TROP2 plays a critical role in cell proliferation, migration and invasion, and its overexpression is frequently linked to aggressive tumor behavior and poor clinical outcomes, the firm noted.

It said its TROP2 cancer vaccine candidates include innovative circular mRNA and fusion protein vaccine constructs that can induce robust T cell immune responses and have demonstrated impressive tumor growth inhibition in preclinical studies.

Preclinical evaluation of TROP2 vaccine candidates

These TROP2 vaccine candidates have been evaluated in five preclinical studies across two tumor types — breast cancer and colorectal cancer — involving over 170 mice, with approximately 100 mice administered a TROP2 vaccine candidate. All breast cancer studies showed complete tumor growth inhibition, according to the filing.

Overall, 100 percent inhibition of tumor growth was achieved in four of the five studies when mice were treated with a TROP2 vaccine candidate, while the remaining study demonstrated approximately 80 percent tumor growth inhibition, CK Life Sciences said.

Developing cancer vaccines is challenging because cancer cells closely resemble healthy cells, each tumor has unique antigens, and tumors can evade immune responses, requiring more sophisticated and personalized approaches than traditional vaccines.

A research team at the LKS Faculty of Medicine, the University of Hong Kong, discovered last year that exosomes derived from γδ-T cells not only have direct anti-tumor effects but also, when developed into a tumor vaccine, can effectively induce a tumor-specific immune response.

Despite the breakthrough, it may take years, if not decades, before any vaccine can be used in cancer treatments for the general public.

STAFF REPORTER

CK Life Sciences stock jumps on cancer vaccine results