• Observed responses to date show overall tumor reduction ranged from 60% to greater than 90%
• Company is expanding trial cohort up to 30 additional patients
• CLR 131 has orphan drug designation for the treatment of Ewing Sarcoma

Cellectar Biosciences (Nasdaq:CLRB), a clinical stage biopharmaceutical company focused on the discovery, development and commercialization of drugs for the treatment of cancer, today announces positive interim results from the company’s Phase 2 clinical trial for its lead product candidate CLR 131, in patients with diffuse large B-cell lymphoma (DLBCL). After a single 25.0 mCi/m2 IV administration of CLR 131, patients with relapsed/refractory DLBCL were assessed for response. These interim data show a 33% overall response rate (ORR) and a 50% clinical benefit response (CBR). In addition, the observed responses to date show overall tumor reduction ranged from 60% to greater than 90%. As a result of these favorable outcomes, the company has expanded this cohort to include up to 30 additional patients.

“We are very encouraged by the strong response rates and meaningful reductions in tumor volumes seen in the trial to date in this very sick and heavily pretreated relapsed/refractory DLBCL patient population,” stated James Caruso, president and chief executive officer of Cellectar Biosciences. “We believe these data combined with the activity seen to date in other hematologic malignancies further validate the continued development of CLR 131.”

The DLBCL cohort of this Phase 2 trial was initiated in January 2018 and represents the fourth B-cell hematologic cancer to be studied in the trial. All DLBCL patients enrolled are required to have relapsed or refractory disease to multidrug chemotherapy regimens containing rituximab and an anthracycline. Part of the funding for this study is provided by a multimillion-dollar NCI Fast Track SBIR grant.

CLR 131 is Cellectar’s investigational radioiodinated PDC therapy that exploits the tumor-targeting properties of the company's proprietary phospholipid ether (PLE) and PLE analogs to selectively deliver radiation to malignant tumor cells, thus minimizing radiation exposure to normal tissues. CLR 131, is in a Phase 2 clinical study in relapsed or refractory (R/R) MM and a range of B-cell malignancies and a Phase 1 clinical study in patients with (R/R) MM exploring fractionated dosing. The company is currently initiating a Phase 1 study with CLR 131 in pediatric solid tumors and lymphoma, and is planning a second Phase 1 study in combination with external beam radiation for head and neck cancer.

Diffuse large B-cell lymphoma (DLBCL) is an aggressive form of non-Hodgkin’s lymphoma (NHL), accounting for about 30 percent of newly diagnosed cases of NHL in the United States. The American Cancer Society’s most recent estimates for NHL for 2018 project approximately 74,680 people (41,730 males and 32,950 females) will be diagnosed with NHL including both adults and children.  They estimate that approximately 19,910 people will die from this cancer (11,510 males and 8,400 females).

The FDA has granted Orphan Drug Status to CLR 131 for the treatment of Ewing Sarcoma. Additionally, CLR 131 is being studied in multiply myeloma and a number of pediatric tumors.