Dr Hernandez-Ilizaliturri on the Potential Advantages of Iopofosine I 131 in Waldenström Macroglobulinemia

Francisco Hernandez-Ilizaliturri, MD, director, Lymphoma Research, professor, oncology, Department of Medicine, head, Lymphoma Translational Research Lab, associate professor, Department of Immunology, Roswell Park Comprehensive Cancer Center; clinical professor, Department of Medicine, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, discusses the unique potential advantages of the radiotherapeutic iopofosine I 131 (formerly CLR 131) compared with other available agents for patients with Waldenström macroglobulinemia.

Iopofosine I 131 was initially evaluated in the phase 2 CLOVER-1 trial (NCT02952508) across various B-cell malignancies. In this trial, the agent displayed notable efficacy and safety signals for heavily pretreated patients with Waldenström macroglobulinemia. These findings prompted the initiation of the CLOVER-WaM expansion cohort within the study for patients with Waldenström macroglobulinemia.

Initial data from the expansion cohort demonstrated durable responses and a tolerable safety profile for iopofosine I 131 in this population, according to Hernandez-Ilizaliturri. Despite the limited duration of follow-up, ongoing observations indicate that responses may continue to improve over time, even months after treatment completion, potentially providing iopofosine I 131 with a notable advantage over current therapies, Hernandez-Ilizaliturri states.

Distinguishing features of iopofosine I 131 include its novel mechanism of action and finite treatment duration, contrasting with continuous therapies, such as BTK inhibitors, Hernandez-Ilizaliturri explains. Despite producing deep responses, iopofosine I 131 offers the potential for treatment completion, which may be preferable for certain patients, he adds.

Safety data from 44 patients with Waldenström macroglobulinemia receiving iopofosine I 131 revealed that hematologic toxicities associated with the agent were primarily grade 1/2, with some instances of grade 3 or higher anemia or neutropenia, Hernandez-Ilizaliturri continues. Importantly, these adverse effects (AEs) were reversible, he adds. Unlike other available agents for patients with Waldenström macroglobulinemia, no vascular or renal AEs were reported with iopofosine I 131, he notes. These preliminary efficacy and safety findings underscore the favorable profile of this novel therapeutic option for patients with Waldenström macroglobulinemia, Hernandez-Ilizaliturri concludes.