Junshi Biosciences and Merck announced their collaboration on a clinical trial program designed to investigate the efficacy and safety of anti-PD-1 mAb toripalimab (TUOYI?) in combination with Cetuximab (Erbitux?) as a treatment for recurrent and/or metastatic squamous cell carcinomas of the head and neck (R/M SCCHN) in China.

Head and neck cancer is one of the most common cancer types in China, ranking 7th in terms of incidence and mortality. Each year, there are more than 135,000 new cases and about 70,000 deaths. And the vast majority (more than 90%) are squamous cell carcinomas. Head and neck cancers are highly heterogeneous and vary across subsites, leading to a potentially devastating impact on patients’ physical and psychological well-being, as well as overall quality of life. Anti-EGFR monoclonal antibody and PD-1 inhibitors have been proved effective in the treatment of R/M SCCHN. However, there are still unmet needs for better treatment options to further improve patients’ response, prolong survival, and improve their quality of life.

Cetuximab (Erbitux?) is an IgG1 monoclonal antibody that specifically targets the EGFR. The inhibition of EGFR blocks the processes involved in tumor cell growth and progression. Cetuximab is also a potent inducer of antibody-dependent cell mediated cytotoxicity (ADCC), inducing antitumor immune effect. In February 2020, Cetuximab was granted an approval by China’s National Medical Products Administration (NMPA) for the first-line treatment of R/M SCCHN using a combination chemotherapy regimen (platinum plus 5-FU).

Developed by Junshi Biosciences, toripalimab (TUOYI?) is the first domestically marketed PD-1 monoclonal antibody in China. Anti-PD-1 mAb is an immunotherapy that can activate and direct the body’s own immune system to attack tumor cells by inhibiting the PD-1 pathway. Over 30 toripalimab mono and combo clinical trials have been conducted globally for more than 10 tumor types, and show encouraging anti-tumor outcomes.

Cetuximab and PD-1 inhibitors are believed to have a synergistic mechanism of action in SCCHN treatment. Preliminary data of early-phase studies have shown promising results from combining immune checkpoint inhibitors with cetuximab.

"Junshi Biosciences has always been concerned with the unmet treatment needs of patients, and has highly prioritized tumors that have a high prevalence and require urgent treatment,” said Dr. Ning Li, CEO of Junshi Biosciences. “Research has shown that anti-PD-1 combination therapy could enhance clinical efficacy of anti-PD-1 mAb, and that the future direction of tumor treatment will increasingly focus on combination therapy, using multiple mechanisms of action to fight tumors. Merck’s Cetuximab, which has been approved for treatment of head and neck squamous cell carcinoma, is one of the ideal drug candidates for combined use with anti-PD-1 drugs. We look forward to benefiting more patients with the combination of targeted therapy and immunotherapy in the treatment of SCCHN.”

"The partnership combines the strengths of both Merck and Junshi Biosciences to explore the effects of targeted and immune combination therapy, with the purpose of providing better and more effective cancer treatment for patients with head and neck cancers in China,” said Rogier Janssens, Managing Director and General Manager of Merck's Biopharma business in China. “This collaboration demonstrates our company’s strong commitment to advancing cancer care and easing the burden the disease poses on patients with R/M SCCHN and other cancer types."

Toripalimab is an anti-PD-1 monoclonal antibody developed by Junshi Biosciences. Toripalimab received its first approval for 2nd line treatment of metastatic melanoma on December 17, 2018 in China and was commercially launched in February 2019.

ERBITUX? is an IgG1 monoclonal antibody targeting the epidermal growth factor receptor (EGFR). As a monoclonal antibody, the mode of action of ERBITUX? is distinct from standard non-selective chemotherapy treatments in that it specifically targets and binds to the EGFR. This binding inhibits the activation of the receptor and the subsequent signal-transduction pathway, which results in reducing both the invasion of normal tissues by tumor cells and the spread of tumors to new sites. It is also believed to inhibit the ability of tumor cells to repair the damage caused by chemotherapy and radiotherapy and to inhibit the formation of new blood vessels inside tumors, which appears to lead to an overall suppression of tumor growth. Based on in vitro evidence, ERBITUX? also targets cytotoxic immune effector cells towards EGFR-expressing tumor cells (antibody-dependent cell-mediated cytotoxicity [ADCC]).