Dr Sullivan on ctDNA Reduction After Tebentafusp Treatment in Uveal Melanoma

Source: OncLive, April 2023

Ryan J. Sullivan, MD, associate professor, medicine, Harvard Medical School; associate professor, hematology/oncology, Massachusetts General Hospital, discusses findings from a study investigating the effects of early circulating tumor DNA (ctDNA) reduction on overall survival (OS) in patients with uveal melanoma treated with tebentafusp-tebn (Kimmtrak).

In this trial, patients with metastatic uveal melanoma received 68 mcg of intravenous tebentafusp weekly after dose escalation. The investigators collected sera from 202 patients at baseline and week 9 and analyzed the sera for ctDNA mutations using a 15-gene targeted assay. Of these patients, 61% had detectable ctDNA mutations at baseline.

By week 9 of tebentafusp treatment, 88% of patients with previously untreated disease had reduced ctDNA levels, 44% had at least a 50% reduction in ctDNA levels, and 37% had total ctDNA clearance. The patients with detectable ctDNA at baseline who achieved total ctDNA clearance with tebentafusp treatment were more likely to survive longer than those without total clearance, Sullivan says.