Xevinapant plus radiotherapy in resected, high-risk, cisplatin-ineligible LA SCCHN: the phase III XRay Vision study design

There is a significant unmet need and lack of treatment options for patients with resected, high-risk, cisplatin-ineligible locally advanced squamous cell carcinoma of the head and neck (LA SCCHN). Xevinapant, a first-in-class, potent, oral, small-molecule IAP inhibitor, is thought to restore cancer cell sensitivity to chemotherapy and radiotherapy in clinical and preclinical studies. We describe the design of XRay Vision (NCT05386550), an international, randomized, double-blind, phase III study. Approximately 700 patients with resected, high-risk, cisplatin-ineligible LA SCCHN will be randomized 1:1 to receive 6 cycles of xevinapant or placebo, in combination with radiotherapy for the first 3 cycles. The primary end point is disease-free survival, and secondary end points include overall survival, health-related quality of life, and safety.

Targeting Inhibitor of Apoptosis Proteins to Overcome Chemotherapy Resistance-A Marriage between Targeted Therapy and Cytotoxic Chemotherapy

Precision oncology is the ultimate goal of cancer treatment, i.e., to treat cancer and only cancer, leaving all the remaining cells and tissues as intact as possible. Classical chemotherapy and radiotherapy, however, are still effective in many patients with cancer by effectively inducing apoptosis of cancer cells. Cancer cells might resist apoptosis via the anti-apoptotic effects of the inhibitor of apoptosis proteins. Recently, the inhibitors of those proteins have been developed with the goal of enhancing the cytotoxic effects of chemotherapy and radiotherapy, and one of them, xevinapant, has already demonstrated effectiveness in a phase II clinical trial. This class of drugs represents an example of synergism between classical cytotoxic chemo- and radiotherapy and new targeted therapy.

Long-term results from a clinical study of xevinapant plus chemoradiotherapy in people with high-risk locally advanced squamous cell carcinoma of the head and neck: a plain language summary

WHAT IS THIS SUMMARY ABOUT?

Squamous cell carcinoma of the head and neck (SCCHN) is the most common type of head and neck cancer. About half of the people with locally advanced (LA) SCCHN will have surgery to remove their cancer. For people who do not have surgery, chemoradiotherapy is the standard treatment, with the aim of fully removing the cancer. However, in many people, this treatment does not completely kill the cancer. This summary presents the main results of a phase 2 study of a medicine called xevinapant, which is under investigation as a potential future medicine for people with this type of cancer.

WHAT DID THE RESEARCHERS WANT TO FIND OUT?

In this study, researchers wanted to find out whether xevinapant plus chemoradiotherapy could stop the cancer from growing back or getting worse in the years after treatment completion in people with LA SCCHN. They also looked at whether people with this type of cancer had side effects from taking this medicine. Short-term results were collected 18 months after treatment with chemoradiotherapy ended. These results showed that people who received xevinapant plus chemoradiotherapy were less likely to have their cancer grow back, or get worse in the part of the body where it was first found, than people who received liquid placebo-which looked and tasted the same as the active medicine (in this case, xevinapant), but did not contain any medicine-plus chemoradiotherapy. Researchers then continued to collect information for a longer amount of time (at least 3 years). They wanted to see if treatment with xevinapant plus chemoradiotherapy was stopping the cancer from growing back or getting worse and helping people live longer. After this, people were monitored for a further 2 years to see if they were alive 5 years after treatment.

WHAT WERE THE MAIN FINDINGS OF THE STUDY?

The results showed that people with this type of cancer who were treated with xevinapant plus chemoradiotherapy were less likely to die, lived longer on average, and were less likely to have their cancer get worse. A phase 3 study, named TrilynX, in a larger group of people, is currently taking place to confirm the results of this study. Clinical Trial Registration: NCT02022098 (Debio 1143-201 Dose-finding and Efficacy Phase I/II Trial) (ClinicalTrials.gov).

The expanding role of IAP antagonists for the treatment of head and neck cancer

Inhibitors of apoptosis proteins (IAPs) inhibit the intrinsic and extrinsic cell death pathways, promoting cell survival. Antagonists of these pathways are under study as anti-cancer therapeutics. A high proportion of head and neck squamous cell carcinomas (HNSCCs) have genomic alterations in IAP pathways, resulting in the dysregulation of cell death pathways and rendering them susceptible to IAP antagonist therapy. Preclinical studies suggest IAP antagonists, also known as second mitochondria-derived activator of caspases mimetics, may be effective treatments for HNSCC, especially when combined with radiation. Mechanistic studies have shown both molecular mechanisms (i.e., enhanced cell death) and immune mechanisms (e.g., immunogenic cell death and T-cell activation), underlying the efficacy of these drugs in preclinical models. Phase I/II clinical trials have shown promising results, portending a future where this class of targeted therapies becomes incorporated into the treatment paradigm for head and neck cancers. IAP antagonists have shown great promise for head and neck cancer, especially in combination with radiation therapy. Here, we review recent preclinical and clinical studies on the use of these novel targeted agents for head and neck cancer.

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 end point is event-free survival by blinded independent review committee. Secondary end points include progression-free survival, locoregional control, overall survival and safety.