The AACR Annual Meeting 2023 took place from April 14-19. During the meeting, stakeholders from across the cancer community—from patients to clinicians—come together to discuss trends, research, and clinical practice. Hematology Advisor reports that one poster presentation centered around early data from the Phase 2/3 PREACH-M study. Within the study, researchers are evaluating the safety, efficacy, and tolerability of lenzilumab when used in conjunction with azacitidine for people living with newly diagnosed chronic myelomonocytic leukemia (CMML). 

First, let’s explore what lenzilumab is. The National Cancer Institute describes lenzilumab as:

a recombinant monoclonal antibody against the cytokine granulocyte macrophage colony-stimulating factor (GM-CSF), with potential immunomodulating activity. Upon administration, lenzilumab binds to and neutralizes GM-CSF [and] prevents GM-CSF binding to the GM-CSF receptor, which is a heterodimeric protein expressed on myeloid progenitor cells, and prevents GM-CSF-mediated signaling.

Altogether, 72 people with CMML will enroll in this study. In particular, the study is focused on people whose cancer is TET2 or RAS pathway mutated. There will be slight differences in medication administration based on the underlying mutation. Of the patients who have already undergone treatment, 100% have had an objective response to treatment. This means that they responded in some way (partially or complely); these responses within the first 12 treatment cycles is considered the trial’s primary endpoint. While this early efficacy shows promise, there were some issues with tolerability, including two serious adverse reactions that could have been caused by this drug.

What is Chronic Myelomonocytic Leukemia (CMML)?

Chronic myelomonocytic leukemia is a rare blood cancer that forms in cells of the bone marrow before invading blood cells. It is considered a myelodysplastic/myeloproliferative neoplasm; other conditions in this group include atypical chronic myeloid leukemia. Doctors don’t know the exact cause of CMML in most cases. However, prior cancer treatmnt has been implicated in a smaller subset. Being older in age and being male are also risk factors of developing this cancer. In people with CMML, their bone marrow creates too many white blood cells (monocytes). This is a key indicator of CMML. Symptoms may, but do not always, include:

• Anemia (low red blood cell count)
• Enlarged liver and spleen
• Frequent and potentially severe infections
• Fatigue
• Extremely pale skin
• Shortness of breath
• Abdominal pain
• Easy bruising and bleeding
• Unintended weight loss
• Fever

There are multiple treatment options for people with CMML: stem cell and bone marrow transplants, chemotherapy, radiation, immunotherapy, and surgery (among others). Clinical trials are also exploring novel options. If you’re interested in joining a clinical trial, please speak with your doctors.