Epcoritamab monotherapy produces noteworthy response rates with manageable safety in patients who have Richter transformation (RT), according to updated results from the phase Ib/II EPCORE CLL-1 trial presented at the 2024 Pan Pacific Lymphoma Conference in Lahaina, Hawaii.
Initial trial findings on use of this subcutaneous bispecific antibody to treat chronic lymphocytic leukemia (CLL) and RT were promising, and trial investigators presented results at the conference from a larger patient cohort with longer follow-up.
“These highly encouraging data support further evaluation of epcoritamab as a chemotherapy-free treatment option for [patients] with RT,” the investigators wrote.
The cohort included 35 adult patients with a median age of 69 years. Among these patients, 91% had received at least one prior treatment for CLL or RT and 49% had prior treatment specifically for RT. The cohort received epcoritamab 48 mg in 28-day cycles until disease progression and had a median follow up of 8.1 months.
In the 26 patients for whom response could be evaluated, the overall response rate was 50% and 35% of patients achieved complete response (CR). Among those patients who had achieved CR, the investigators estimated that 53% were still in CR at nine months, and that this rate specifically among patients with untreated RT was higher still at 75%.
“Safety was tolerable and consistent with prior reports. Most cytokine release syndrome was low grade, and no new safety signals were observed,” the investigators wrote regarding treatment emergent adverse events (TEAEs).
CRS was the most common nonhematologic TEAE and occurred in 80% of the cohort. Four patients experienced immune effector cell-associated neurotoxicity syndrome (ICANS) and clinical tumor lysis syndrome (CTLS) occurred in three patients. However, no CRS, ICANS, or CTLS instances led to epcoritamab discontinuation. There were three mortalities in the trial, with two from general physical health deterioration and one due to sepsis.
Reference
Kater AP, Janssens A, Eradat H, et al. Single-agent epcoritamab leads to deep responses in patients (pts) with Richter’s transformation (RT): primary results from the EPCORE CLL-1 trial. 2024 Pan Pacific Lymphoma. July 15-19; Lahaina, Hawaii.