Cellectar Biosciences Soars 15.85% on Positive CLOVER-2 Trial Results

On June 11, 2025, Cellectar Biosciences, Inc. (NASDAQ: CLRB) saw a significant pre-market rise of 15.85%, driven by positive updates from its CLOVER-2 Phase 1 clinical trial.

Cellectar Biosciences announced encouraging initial results from the CLOVER-2 Phase 1 clinical trial, which is evaluating iopofosine I 131 in relapsed/refractory pediatric high-grade glioma (pHGG) patients. The trial included patients diagnosed with various aggressive tumors affecting the brain and central nervous system, such as diffuse midline gliomas, ependymomas, and diffuse intrinsic pontine gliomas. The median progression-free survival (PFS) and overall survival (OS) for these patients are typically poor, with PFS around 2.25 months and OS around 5.6 months.

Patients receiving a minimum of 55 mCi total administered dose experienced an average PFS of 5.4 months and OS of 8.6 months, with all patients achieving disease control. Three patients who received additional dosing cycles showed an average PFS of 8.1 months and OS of 11.5 months, with two achieving an objective response. The drug was well tolerated, with no significant cardiovascular, renal, or liver toxicities reported. The most common adverse events were hematologic in nature and were manageable.

Cellectar Biosciences is optimistic about the potential of iopofosine I 131 to treat aggressive cancers, especially for patients with limited treatment options. The company's proprietary Phospholipid Drug Conjugate™ (PDC) delivery platform aims to develop cancer cell-targeting treatments with improved efficacy and better safety profiles. The CLOVER-2 trial is ongoing, with plans to evaluate the safety, tolerability, and therapeutic activity of iopofosine I 131 in relapsed/refractory high-grade glioma patients.