A new radiotherapeutic agent, iopofosine I 131, is showing promising potential for patients with Waldenström macroglobulinemia, according to Francisco Hernandez-Ilizaliturri, MD, of Roswell Park Comprehensive Cancer Center. The initial phase 2 CLOVER-1 trial demonstrated notable efficacy and safety signals for heavily pretreated patients with this condition, leading to the initiation of the CLOVER-WaM expansion cohort specifically for Waldenström macroglobulinemia.
Preliminary data from the expansion cohort indicated durable responses and a manageable safety profile for iopofosine I 131, with ongoing observations suggesting that responses may continue to improve months after treatment completion. This unique feature could give iopofosine I 131 an advantage over current therapies, Hernandez-Ilizaliturri noted.
One of the key features of iopofosine I 131 is its novel mechanism of action and finite treatment duration compared to continuous therapies like BTK inhibitors. Despite providing deep responses, iopofosine I 131 allows for treatment completion, which may be preferable for some patients.
Safety data from 44 patients with Waldenström macroglobulinemia receiving iopofosine I 131 showed primarily grade 1/2 hematologic toxicities, with reversible instances of grade 3 or higher anemia or neutropenia. Importantly, no vascular or renal adverse effects were reported with iopofosine I 131, setting it apart from other available agents for this condition.
Overall, the preliminary efficacy and safety findings suggest that iopofosine I 131 could be a favorable therapeutic option for patients with Waldenström macroglobulinemia. This new radiotherapeutic agent offers hope for improved outcomes in this patient population.