Epcoritamab study results reported at American Society of Hematology’s conference press briefing in San Diego

City of Hope^®, one of the largest and most advanced cancer research and treatment organizations in the United States, whose Los Angeles comprehensive cancer center is ranked among the nation’s top five cancer centers by U.S. News & World Report, reported on promising early results from a phase 1b/2 clinical trial using epcoritamab, a new bispecific T cell engager, for patients with relapsed or refractory CLL.

Alexey Danilov, M.D., Ph.D., City of Hope’s Marianne and Gerhard Pinkus Professor in Early Clinical Therapeutics, and associate director of the Toni Stephenson Lymphoma Center, revealed EPCORE CLL-1 study results (Abstract No. 883 Epcoritamab Monotherapy in Patients (Pts) with Relapsed or Refractory (R/R) Chronic Lymphocytic Leukemia (CLL): Results from CLL Expansion and Optimization Cohorts of Epcore CLL-1) at the ASH conference held in San Diego Dec. 7 to 10.

As part of the ongoing, multicenter, nonrandomized trial, Dr. Danilov and team reported data from the first 40 patients of the study. With a median age of 71.5, all participants received the same dose of the therapy but in the monotherapy expansion (EXP) cohort, 23 people received epcoritamab in three increasing doses. Seventeen patients in the optimization (OPT) group received the therapy in four increasing doses.

In the EXP group, the overall response rate after a median time of nearly two years was 61% and 39% of these patients had no signs of cancer at follow-up. This is especially significant because the study participants are mainly “double refractory” — people who have progressed on both BTK and BCL2 inhibitors, which is a very difficult population to treat, Dr. Danilov added.

The OPT cohort represents patients enrolled later in the trial and effectiveness data is not yet available, but side effects are being monitored and measured. No patient in either cohort has discontinued the trial due to adverse effects from the therapy.

“Our early results show this single-agent therapy had a high overall response rate for CLL patients who have been heavily pre-treated and was safe to use,” Dr. Danilov said. “This is a first-of-its kind treatment for CLL. It takes a very novel approach that has not yet been studied in CLL, and is very different from available CLL treatments.”

The most common form of leukemia among adults in the U.S., CLL is diagnosed in more than 20,000 Americans (mostly 65 years or older) a year. People with CLL that has come back or not responded after two or more therapies lack options for additional treatments. Furthermore, the standard of care for all CLL patients — two classes of targeted drugs known as BTK and BCL2 inhibitors — eventually stops working for most patients.

Epcoritamab, which is injected under the skin and is currently approved by the U.S. Food and Drug Administration to treat two types of relapsed and refractory lymphomas, is a type of monoclonal antibody that leverages a patient’s own immune system. It binds to the CD20 marker on diseased B cells, which makes those cells better targets for the immune system’s T cells to destroy. Epcoritamab also binds to the CD3 marker on T cells, pulling them closer to the B cells for a more efficient attack.

“While the sample size is small, we hope to validate these findings as the study progresses,” he added, noting that he would also like to use epcoritamab earlier in the course of disease for CLL patients to find out if it is more effective when people’s immune systems have not yet been challenged by multiple therapies.

First Patient Treated in Trial in Remission

The first person to enroll in the EPCORE CLL-1 clinical trial was Brian Koffman, M.D., a 73-year-old retired family physician who was first diagnosed with CLL in 2005. A prior stem cell transplant at City of Hope and two different clinical trial therapies put him in remission for periods of time, but in 2022, Dr. Koffman found himself facing CLL once again.

More than a year into his trial participation, Dr. Koffman, who is the founder and director of CLL Society, a worldwide leader in informing patients with CLL and small lymphocytic leukemia about the latest treatments, is in full remission. His maintenance plan is simple: a “non-event,” as he calls it. Once a month, he visits City of Hope for tests, bloodwork and his epcoritamab injection, “a 30-second shot.” Within an hour, he’s headed home.

Dr. Koffman has had no major side effects since the first five weeks of the trial when researchers were still figuring out the proper dosage and countering cytokine release syndrome (CRS) — an overreaction of the immune system that can cause mild to severe symptoms like fever, headache and nausea — with steroids. CRS was the most frequent nonblood-related adverse effect seen in early trial data, occurring in 96% of the EXP cohort patients. In most cases, CRS was mild, and Dr. Danilov believes the risk can be mitigated by scaling up dosing in a three-stage approach.

Dr. Danilov is optimistic that epcoritamab could be the treatment that puts Dr. Koffman���s CLL into lasting remission.

“It’s still very early,” he added. “And we need more data, but I think it’s possible some users of epcoritamab will see long-term results.”

Genmab, a biotechnology company that is co-developer of epcoritamab with the pharmaceutical company AbbVie, funded the study, which aims to enroll 184 people. Dr. Danilov serves as a paid consultant to Genmab and AbbVie.

About City of Hope

City of Hope’s mission is to make hope a reality for all touched by cancer and diabetes. Founded in 1913, City of Hope has grown into one of the largest and most advanced cancer research and treatment organizations in the U.S., and one of the leading research centers for diabetes and other life-threatening illnesses. City of Hope research has been the basis for numerous breakthrough cancer medicines, as well as human synthetic insulin and monoclonal antibodies. With an independent, National Cancer Institute-designated comprehensive cancer center that is ranked top 5 in the nation for cancer care by U.S. News & World Report at its core, City of Hope’s uniquely integrated model spans cancer care, research and development, academics and training, and a broad philanthropy program that powers its work. City of Hope’s growing national system includes its Los Angeles campus, a network of clinical care locations across Southern California, a new cancer center in Orange County, California, and cancer treatment centers and outpatient facilities in the Atlanta, Chicago and Phoenix areas. City of Hope’s affiliated group of organizations includes Translational Genomics Research Institute and AccessHope^TM. For more information about City of Hope, follow us on Facebook, X, YouTube, Instagram and LinkedIn.

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