Three major Mount Sinai research studies offer new hope for patients facing chronic lymphocytic leukemia (CLL), a rare type of blood cancer. The studies were led by Adam Kittai, MD, Associate Professor of Medicine (Hematology and Medical Oncology) at the Icahn School of Medicine at Mount Sinai and the Director of Mount Sinai’s CLL Program. As one of the world’s leading experts on Richter transformation, Dr. Kittai aims to increase awareness about Mount Sinai’s CLL program and welcome patients in need of a second opinion.

CLL is a slow-growing type of lymphoma that is often treated successfully, and many people live with it for years. However, in a small number of patients, CLL can change into a much more aggressive cancer called Richter transformation. This condition is more difficult to treat and can quickly become life-threatening.

CLL accounts for about 1 in 3 new cases of leukemia in the United States, and about 1% of cancers overall, according to the American Cancer Society. In the past, most people with Richter transformation had a survival time of only 6 to 12 months. Dr. Kittai’s recent research shows that some patients—especially those who have not had prior chemotherapy for their CLL—may now live up to two years or more.

Three high-impact papers about Richter transformation

Dr. Kittai’s first study, published in the April 2025 issue of Blood) is the largest analysis to date of CAR T-cell therapy for Richter transformation, showing that this treatment can lead to long-term remission in some patients.

The second study, published in the February 2025 issue of Blood Cancer Journal, looked at a group of patients who had never received chemotherapy for CLL and found they lived longer than expected after developing Richter transformation.

The third paper, published in the March 2024 issue of Journal of Clinical Oncology, brought together top researchers from around the world to create guidelines for diagnosing and studying Richter transformation.

“These studies show that we’re starting to make progress. We’re giving patients more options—and more hope,” said Dr. Kittai. “Richter transformation can be scary, but we now have new ways to fight it. Our goal is to give patients more time and better outcomes.”

New clinical trial at Mount Sinai

Dr. Kittai is leading a new clinical trial at Mount Sinai that tests a powerful combination treatment for Richter transformation: CAR-T cell therapy along with a drug called zanubrutinib, a BTK inhibitor. BTK, inhibitors are drugs that can interfere with the signaling pathways that promote the growth and survival of cancerous B cells, making them a valuable treatment option for certain blood cancers. This trial is one of only two like it in the United States. It gives eligible patients access to advanced treatment, even early in their diagnosis.

“We’re excited about this trial because it may improve survival for people with this rare disease,” said Dr. Kittai. “And we can get patients started quickly, which is important because Richter transformation can get worse fast.”

Because Richter transformation is so rare and aggressive, Dr. Kittai encourages doctors to refer patients early and consider clinical trials. He and his team are accepting new patients for second opinions and trial evaluations.

“If you or your patient is facing Richter transformation, we are here to help,” said Dr. Kittai. “This is a difficult disease, but we now have treatments that are showing real promise.”