The company stated that its decision was informed by a pre-planned interim analysis performed by the Independent Data Monitoring Committee. It found that the study is “unlikely to meet its primary objective of prolonging event-free survival”.
Following the news of trial termination, Merck’s stock was down by over 10% in trading on the Frankfurt Stock Exchange.
The randomised placebo-controlled Phase III TrilynX trial (NCT04459715) enrolled approximately 730 participants with LA SCCHN. The study evaluated xevinapant in combination with chemoradiation therapy versus placebo and chemoradiation. The trial’s primary endpoint was event-free survival for up to five years.
Merck was quick to add that the safety data for xevinapant was “overall compatible with the chemo-radio sensitizing properties of the therapy”. The company plans to conduct an in-depth review of the data and share these results in the future.
Xevinapant was touted as Merck’s big oncology therapy, per its 2023 annual statement. The company prioritised its importance, especially after its multiple sclerosis therapy, evobrutinib, failed to meet primary endpoints in Phase II trials.
In April, Merck invested over €300m ($320.8m) in a new Life Science Research Center at its global headquarters in Darmstadt, Germany. The centre, which is expected to open in 2027, will be responsible for developing biopharmaceuticals, including antibodies and messenger ribonucleic acid applications.