Inhibiting the inhibitors: Development of the IAP inhibitor xevinapant for the treatment of locally advanced squamous cell carcinoma of the head and neck

Cancer Treat Rev. 2023 Feb:113:102492. doi: 10.1016/j.ctrv.2022.102492. Epub 2022 Nov 30.

Abstract

Standard of care for patients with locally advanced squamous cell carcinoma of the head and neck (LA SCCHN) is surgery followed by chemoradiotherapy (CRT) or definitive CRT. However, approximately 50 % of patients with LA SCCHN develop disease recurrence or metastasis within 2 years of completing treatment, and the outcome for these patients is poor. Despite this, the current treatment landscape for LA SCCHN has remained relatively unchanged for more than 2 decades, and novel treatment options are urgently required. One of the key causes of disease recurrence is treatment resistance, which commonly occurs due to cancer cells' ability to evade apoptosis. Evasion of apoptosis has been in part attributed to the overexpression of inhibitor of apoptosis proteins (IAPs). IAPs, including X-linked IAP (XIAP) and cellular IAP 1 and 2 (cIAP1/2), are a class of proteins that regulate apoptosis induced by intrinsic and extrinsic apoptotic pathways. IAPs have been shown to be overexpressed in SCCHN, are associated with poor clinical outcomes, and are, therefore, a rational therapeutic target. To date, several IAP inhibitors have been investigated; however, only xevinapant, a potent, oral, small-molecule IAP inhibitor, has shown clinical proof of concept when combined with CRT. Specifically, xevinapant demonstrated superior efficacy in combination with CRT vs placebo + CRT in a randomized, double-blind, phase 2 trial in patients with unresected LA SCCHN. Here, we describe the current treatment landscape in LA SCCHN and provide the rationale for targeting IAPs and the clinical data reported for xevinapant.

Keywords: Apoptosis; Chemoradiotherapy; Inhibitor of apoptosis protein; Locally advanced squamous cell carcinoma of the head and neck; Xevinapant.

Publication types

  • Review

MeSH terms

  • Antineoplastic Agents* / therapeutic use
  • Carcinoma, Squamous Cell* / drug therapy
  • Clinical Trials, Phase II as Topic
  • Head and Neck Neoplasms* / drug therapy
  • Humans
  • Neoplasm Recurrence, Local / drug therapy
  • Randomized Controlled Trials as Topic
  • Squamous Cell Carcinoma of Head and Neck / drug therapy

Substances

  • Antineoplastic Agents