Shanghai Henlius Biotech, Inc. (2696.HK) announced that the filing of a clinical trial for HLX301, a Recombinant Humanized Anti-PDL1 and Anti-TIGIT Bispecific Antibody, in Patients with locally advanced or metastatic solid tumours has been approved by the Bellberry Human Research Ethics Committee ("HREC"), and Clinical Trial Notification ("CTN") has been acknowledged by the Therapeutic Goods Administration ("TGA"), Australia. The Phase 1 clinical study in Australia is intended to be initiated soon. No bispecific antibody targeting PD-1/PD-L1 and TIGIT has been approved for marketing globally yet.

Immunotherapies targeting immune checkpoint protein interactions between ligands and receptors offer a novel way to attack tumour cells in recent years. PD-1/PD-L1 plays a vital role in immune suppression; PD-1 and PD-L1 inhibitors show significant effectiveness in cancer treatment. TIGIT (T cell immunoreceptor with immunoglobulin and ITIM domains) is an inhibitory receptor, mainly expressed on natural killer (NK) cells and activated T cells and T regulatory cells. TIGIT binds to the major ligand CD155 (poliovirus receptor, PVR), mainly expressed on antigen-presenting cells (APC) or tumour cells, to down-regulate T cell and NK cell functions. TIGIT can inhibit innate and adaptive responses in various mechanisms and act as a "brake" like PD-1/PD-L1 does to stop T cells from attacking tumours. Several pre-clinical studies have indicated that TIGIT blockade may be effective against multiple advanced cancers, including NSCLC, GC, melanoma, and MM.

Independently developed by Henlius, HLX301 is an innovative anti-PD-L1 and anti-TIGIT bispecific antibody. Its TIGIT binding domain is derived from VHH fragments with high affinity and specificity to TIGIT, selected from the company's synthetic humanized llama VHH library. Pre-clinical studies reported that HLX301 can simultaneously block both PD-1/PDL1 and TIGIT/PVR pathways, restore TCR signaling, inhibit tumour growth, and has good tolerance and safety. These results suggested that HLX301 is superior to blocking either pathway alone or anti-PD-L1 + anti-TIGIT combination therapy, paving the way for further clinical development.

Underpinned by the patient-centric strategy, Henlius achieves an overall layout of the immune checkpoint products of PD-1/L1, CTLA-4, LAG-3, BRAF, etc., proactively exploring immuno-oncology combination therapy, bispecific antibodies and ADC. Looking forward, Henlius will continue strengthening the in-licensing and collaboration on external innovative assets and bringing high-quality and affordable therapies to patients worldwide.

Source: Henlius