Pharmacotherapy of relapsed/refractory chronic lymphocytic leukemia

Monoclonal Antibodies, Bispecific Antibodies and Antibody-Drug Conjugates in Oncohematology

Background:

The therapeutic outcomes and the prognosis of patients with various hematologic malignancies are not always ideal with the current standard of care.

Objective:

The aim of this study is to analyze the results of the use of monoclonal antibodies, bispecific antibodies and antibody-drug conjugates for the therapy of malignant hemopathies.

Methods:

A mini-review was achieved using the articles published in Web of Science and PubMed between January 2017 and January 2020 and the new patents were made in this field.

Results:

Naked monoclonal antibodies have improved the therapeutic results obtained with standard of care, but they also have side effects and the use of some of them can lead to the loss of the target antigen through trogocytosis, which explains the resistance that occurs during therapy. The results obtained with naked monoclonal antibodies have been improved by a better monoclonal antibody preparation, the use of bispecific antibodies (against two antigens on the target cell surface or by binding both surface antigen on target cells and T-cell receptor complex, followed by cytotoxic T-lymphocytes activation and subsequent cytolysis of the target cell), the use of monoclonal or bispecific constructs in frontline regimens, combining immunotherapy with chemotherapy, including through the use of antibody-drug conjugates (which provides a targeted release of a chemotherapeutic agent).

Conclusion:

Immunotherapy and immuno-chemotherapy have improved the outcome of the patients with malignant hemopathies through a targeted, personalized therapy, with reduced systemic toxicity, which in some cases can even induce deep complete remissions, including minimal residual disease negativity.

Unusual Relapse of Chronic Lymphocytic Leukemia After Remission

Chronic lymphocytic leukemia (CLL) is the most prevalent leukemia with over 20,000 estimated cases in 2017. Leukemic involvement of the nervous system from CLL causing neurologic symptoms is reported in only about one percent of patients. Unfortunately, there is no current standard therapy for the treatment of CLL leptomeningeal disease. In this case, we discuss an unusual presentation of CLL leptomeningeal disease misdiagnosed as chronic rebound headache.

A 61-year-old female was diagnosed with Rai stage I CLL in 2002. She presented at that time with peripheral blood lymphocytosis and subsequent flow cytometry revealed a mature B cell population consistent with CLL. She was monitored clinically as there were no indications for therapy. In 2006, she developed B symptoms along with hemolytic anemia refractory to steroids and was initiated on chemotherapy with fludarabine, cyclophosphamide, and rituximab (FCR). She had a complete response after six cycles.

The patient was in her usual state of health until 2016, when she complained of chronic headaches. She took acetaminophen and ibuprofen regularly and was diagnosed with rebound headaches by neurology. These symptoms progressed and the patient developed encephalopathy requiring inpatient admission. Magnetic resonance imaging (MRI) revealed abnormal enhancement in the cerebellar peduncles and dentate nuclei symmetrically; a lumbar puncture performed revealed evidence of CLL consistent with leptomeningeal disease. Therapy was started with oral ibrutinib at 560 mg daily for better central nervous system (CNS) penetration. After three months of therapy, she had complete resolution of symptoms and MRI abnormalities.

Leptomeningeal disease is a rare complication of CLL that clinicians should be aware of and ibrutinib can be an effective, tolerable therapy for this debilitating disease.