When people have certain types of B-cell leukemia or lymphoma that no longer respond to standard treatments, options are limited. Other patients need additional therapies called “bridging” before they can receive advanced cell-based treatments like chimeric antigen receptor (CAR T-cell) immunotherapy. Bridge therapy keeps tumors from growing as patients prepare for more treatment.

BTK Inhibitors Used as Bridge Therapy for Cancer Treatments

BTK inhibitors are in a class of drugs that has been used for bridging and for control of relapsed disease, but cancer can become resistant to the drug due to cell mutations or other factors. That leaves patients without effective interim treatment. BTK, short for Bruton tyrosine kinase, is a cell protein that can get stuck in the “on” position, allowing the uncontrolled cell growth typical of cancer.

Nirav Shah, MD, hematologist/oncologist, Medical College of Wisconsin faculty member and researcher, specializes in lymphoma, leukemia and stem cell transplant. He has been an innovator in advanced therapies for B-cell malignancies and was the local investigator leading an international clinical trial to tackle the problem of treatment resistance. The clinical trial tested pirtobrutinib, a unique BTK inhibitor drug, with patients who had chronic lymphocytic leukemia, small lymphocytic lymphoma or mantle cell lymphoma.

Pirtobrutinib Results Show Promise

Results were encouraging; researchers found that pirtobrutinib was safe and effective. Most study participants who went into remission remained well without further disease progression. Trial results published in The Lancet in March 2021 suggest pirtobrutinib, while it needs additional study, could address a growing, unmet need for new therapies.

“For many patients, we look for a drug like pirtobrutinib to act as a bridge to get them to other treatments, such as CAR T-cell therapy or a stem cell transplant,” Dr. Shah said. “To our surprise, for some patients, pirtobrutinib achieved longer-term benefits and remission in this early-phase trial.

“As we continue to collaborate with top cancer centers and leading researchers, I am hopeful we’ll be able to accelerate the availability of alternative cancer therapies for patients in need.”

The Froedtert & MCW Clinical Cancer Center at Froedtert Hospital campus was the only site in the Midwest and one of only 30 centers in the world offering the pirtobrutinib trial sponsored by Loxo Oncology.

For Our Referring Physicians:

Academic Advantage of Oncology Services

The Froedtert & MCW health network gives patients and their referring physicians a distinct advantage.

Contact our physician liaison team for more information about pirtobrutinib or if you would be interested in meeting with any of the hematology and medical oncology team members.