APL-501 is a novel IgG4 humanized monoclonal antibody against the Programmed Death-1 (PD-1) membrane receptor on immune cells. APL-501 specifically binds to PD-1 expressed on the surface of T-cells. It prevents T-cells from binding to PD-L1 present on the surface of tumor cells, thereby allowing T-cells to cause tumor cell death. Preclinical studies have demonstrated that APL-501 has anti-tumor activity comparable to a marketed anti-PD-1 antibody, and a good safety profile with very low antibody-dependent cell mediated cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC).

The PD-(L)1 checkpoint inhibitors, a kind of immune-oncology drug, act through interfering with the PD-(L)1 pathway, which prevents T-cells from attacking tumor cells within the tumor microenvironment. In the cancer disease state, the use of an inhibitor that blocks the interaction between PD-L1 and the PD-1 receptor can prevent certain tumor cells from evading the immune system. PD-(L)1 inhibitors are increasingly used for the treatment of many cancers, and have been proven to have a better efficacy profile and fewer side effects in a number of cancer indications compared to traditional cancer treatments, such as chemotherapy.

PD-(L)1 inhibitors are remarkable for their tolerability and their clinical activity in shrinking tumors across a wide range of tumor types, causing durable responses. These attributes position them as favorable agents in combination therapies.

Anti-tumor activity has been demonstrated in clinical trials of APL-501 run by our China partner, Genor, in patients with r/r peripheral T-cell lymphoma or relapsed/metastatic/unresectable alveolar soft part sarcoma by our partner. In general, these studies showed that APL-501 demonstrates anti-tumor activities across multiple tumor types and has a favorable safety profile. 

Apollomics retains worldwide rights to APL-501 outside mainland China.