QUANTUM trial tests immune-targeting approach for primary plasma cell leukemia

The Alliance for Clinical Trials in Oncology today announced the activation of The QUANTUM Trial (Alliance A062401), a clinical study designed to test a novel, immune-targeting approach for patients newly diagnosed with primary plasma cell leukemia (PCL).

Plasma cell leukemia is a rare but aggressive form of blood cancer with about 1,200 new cases diagnosed in the U.S. each year. It is characterized by high numbers of malignant plasma cells circulating in the bloodstream and long-term survival remains poor.

Because current therapies are often cannot produce durable remissions, researchers are evaluating whether teclistamab-a novel bispecific antibody-can improve outcomes when used as consolidation therapy after stem cell transplantation compared with standard post-transplant treatments. Teclistamab is a next-generation immunotherapy that is FDA-approved for certain patients with multiple myeloma. It works by activating the body's immune system to target and destroy cancer cells.

Plasma cell leukemia progresses rapidly and remains one of the most difficult blood cancers to treat effectively. By introducing the bispecific antibody teclistamab right after stem cell transplantation, the QUANTUM trial aims to harness the patient's own immune system to clear residual cancer cells and with the ultimate goal of meaningfully improving long-term survival."

Douglas Sborov, MD, MS, Professor of Medicine at the University of Utah-Huntsman Cancer Institute, Department of Internal Medicine- Division of Hematology and Hematologic Malignancies and principal investigator of the trial

Participants in the QUANTUM study undergo a multi-phase treatment plan that combines established therapies with a novel bispecific antibody approach:

• Step 1-Induction Phase: All patients will receive four cycles of quadruplet induction therapy consisting of daratumumab, carfilzomib, lenalidomide, and dexamethasone called D-KRd to rapidly reduce cancer cell counts. These drugs work to stop cancer cells from reproducing while mobilizing the patient's immune system against the disease.
• Step 2-Stem Cell Transplant: After induction therapy, patients undergo stem cell mobilization and collection followed by high-dose chemotherapy and an autologous stem cell transplant to rebuild healthy blood-forming cells. This process uses the patient's own healthy blood stem cells to rebuild bone marrow that has been damaged by chemotherapy.
• Step 3-Targeted Consolidation (Key Trial Focus): Following transplantation, patients are randomly assigned to one of two treatment groups. Patients in the experimental arm receive teclistamab while patients in the standard-of-care arm continue D-KRd therapy. The trial is evaluating whether teclistamab consolidation can improve overall survival compared to standard D-KRd treatment.
• Step 4-Maintenance Phase: After consolidation, patients in both treatment groups receive long-term maintenance therapy with carfilzomib and lenalidomide intended to help maintain disease control and delay relapse.

The QUANTUM Trial is sponsored by the National Cancer Institute (NCI) and conducted by the Alliance for Clinical Trials in Oncology. This Phase II study aims to enroll 74 adults at participating cancer centers and medical clinics across the United States.