Merck KGaA’s drug candidate xevinapant in a late-stage trial was unable to significantly improve event-free survival in patients with locally advanced head and neck cancer.
Merck KGaA announced Monday that its drug candidate xevinapant failed the Phase III TrilynX study, unable to yield significant survival benefits in patients with locally advanced head and neck cancer.
The German company did not provide specific data in its news release, only disclosing that an Independent Data Monitoring Committee found that the study was likely to fall short of its primary endpoint “of prolonging event-free survival” at a planned interim analysis. Safety findings were consistent with xevinapant’s chemo-radio-sensitizing effects.
Given the disappointing outcome, Merck KGaA has decided to discontinue TrilynX, which assessed xevinapant in patients with locally advanced squamous cell carcinoma of the head and neck who had not yet undergone resection.
The company will also terminate another Phase III study, dubbed X-Ray Vision, which was evaluating xevinapant plus radiotherapy in locally advanced head and neck cancer patients who had received surgery.
Danny Bar-Zohar, CMO for the healthcare business sector of Merck KGaA, in a statement said that the company was “disappointed” by these results. Nevertheless, “we remain steadfast in our commitment to develop transformative medicines within our oncology portfolio for areas of high unmet need,” according to Bar-Zohar. The pharma said it will conduct an in-depth review of TrilynX’s outcomes and share its findings in a peer-reviewed forum.
Xevinapant is an orally available small-molecule blocker of the inhibitor of apoptosis proteins, a family of anti-apoptotic proteins that help cancer cells survive. Through this mechanism of action, xevinapant is designed to facilitate the death of tumor cells.
The drug candidate was initially developed by Debiopharm International. Merck KGaA paid around $226 million in March 2021 to acquire the exclusive global development and commercial rights to xevinapant.
Xevinapant’s failure deals a blow to Merck KGaA’s oncology portfolio, which the company bolstered in April 2024 with a $1.4 billion deal with Caris Life Sciences. Under the agreement, the two companies will work together for the discovery and development of potentially first-in-class antibody-drug conjugates for cancer.
Monday’s Phase III flop comes after Merck KGaA’s BTK inhibitor evobrutinib in December 2023 fell short of its primary efficacy endpoint in the late-stage evolutionRMS 1 and 2 studies in relapsing multiple sclerosis. Compared with Sanofi’s Aubagio (teriflunomide), the drug candidate was unable to significantly reduce annualized relapse rate.
In March 2023, Merck KGaA decided to terminate the development of evobrutinib in multiple sclerosis.
Tristan Manalac is an independent science writer based in Metro Manila, Philippines. Reach out to him on LinkedIn or email him at tristan@tristanmanalac.com or tristan.manalac@biospace.com.
