Cellectar Biosciences announced today a patient, enrolled in the CLR 131 Phase 2 trial, showed a 94 percent reduction in tumor burden and complete resolution in four of five targeted tumor masses.

“In addition to a robust clinical response, we were also happy to see resolution of symptoms that affected the patient’s quality of life, including shortness of breath associated with moderately sized pleural effusion shortly after the patient’s first dose of CLR 131,” Mayo Clinic Dr. Sikander Ailawadhi said in a statement.

According to a release, the patient, who was diagnosed with Waldenstrom Macroglobulinemia, had a tumor shrink from approximately 4,700-square mm prior to the first CLR 131 infusion to approximately 500-square mm after the last test.

Cellectar and the Mayo Clinic will continue to monitor the patient’s progress.