Xevinapant or placebo plus chemoradiotherapy in locally advanced squamous cell carcinoma of the head and neck: TrilynX phase III study design

Xevinapant is a first-in-class antagonist of inhibitor of apoptosis proteins, which enhances cancer cell sensitivity to chemotherapy and radiotherapy. In a phase II randomized study in patients with unresected locally advanced squamous cell carcinoma of the head and neck (LA SCCHN), xevinapant plus standard-of-care cisplatin-based chemoradiotherapy (CRT) showed superior efficacy versus placebo plus CRT. Here, we describe the design of TrilynX (NCT04459715), a randomized, double-blind, phase III study. In total, 700 patients with unresected LA SCCHN will be randomized 1:1 to receive xevinapant or placebo plus standard-of-care CRT followed by xevinapant monotherapy or placebo. The primary endpoint is event-free survival by blinded independent review committee. Secondary endpoints include progression-free survival, locoregional control, overall survival and safety. Plain language summary: Xevinapant is being developed as a new type of cancer treatment. Xevinapant works by enhancing the effects of chemotherapy and radiotherapy (chemoradiotherapy), which are standard anticancer treatments. Researchers are studying whether adding xevinapant to these treatments could be helpful for people with head and neck cancers that have not spread to other parts of the body and cannot be removed by surgery. In a study of 96 people with this disease, those treated with chemoradiotherapy plus xevinapant on average lived longer than people treated with chemoradiotherapy plus placebo (liquid that looked the same but did not contain any medicine). To confirm the results, researchers have started a larger study, called TrilynX, that will compare the same treatments in around 700 people worldwide. This study will show if adding xevinapant to chemoradiotherapy can help to keep the cancer from progressing, control symptoms better and help people live longer.