MADISON, WIS., 14 March 2017 – Cellectar Biosciences, Inc. (Nasdaq:CLRB) (the "company"), an oncology-focused, clinical stage biotechnology company, today announces the Japanese Patent Office has granted a composition of matter patent for the company's optical imaging phospholipid drug conjugates (PDCs), CLR 1501 and CLR 1502.

The recently issued patent, JP6073961, describes CLR 1501 and CLR 1502 for use in intraoperative tumor imaging both in vitro and in vivo. The patent allows intellectual property protection in Japan through May 11, 2030. Both compounds utilize the company's PDC delivery platform for tumor targeting optimization.

"This patent represents another demonstration of both the unique properties and varied utility of our PDC platform," said Jim Caruso, president and CEO of Cellectar. "While our focus continues to be the development of the PDC platform for therapeutic uses, including our lead product candidate CLR 131 in hematologic malignancies, the additional global patent protection provides us with unique opportunities for partnerships to further explore the clinical utility of our technology and enhance the value of the platform."

About Phospholipid Drug Conjugates (PDCs)

Cellectar's product candidates are built upon its patented cancer cell-targeting delivery and retention platform of optimized phospholipid ether-drug conjugates (PDCs). The company deliberately designed its phospholipid ether (PLE) carrier platform to be coupled with a variety of payloads to facilitate both therapeutic and diagnostic applications. The basis for selective tumor targeting of our PDC compounds lies in the differences between the plasma membranes of cancer cells compared to those of normal cells. Cancer cell membranes are highly enriched in lipid rafts, which are glycolipoprotein microdomains of the plasma membrane of cells that contain high concentrations of cholesterol and sphingolipids, and serve to organize cell surface and intracellular signaling molecules. PDCs have been tested in more than 80 different xenograft models of cancer.

About Cellectar Biosciences, Inc.

Cellectar Biosciences is developing phospholipid drug conjugates (PDCs) designed to provide cancer targeted delivery of diverse oncologic payloads to a broad range of cancers and cancer stem cells. Cellectar's PDC platform is based on the company's proprietary phospholipid ether analogs. These novel small-molecules have demonstrated highly selective uptake and retention in a broad range of cancers. Cellectar's PDC pipeline includes product candidates for cancer therapy and cancer diagnostic imaging. The company's lead therapeutic PDC, CLR 131, utilizes iodine-131, a cytotoxic radioisotope, as its payload. CLR 131 is currently being evaluated under an orphan drug designated Phase I clinical study in patients with relapsed or refractory multiple myeloma. In addition, the company plans to initiate a Phase II clinical study to assess efficacy in a range of B-cell malignancies in the first quarter of 2017. The company is also developing PDCs for targeted delivery of chemotherapeutics such as paclitaxel (CLR 1602-PTX), a preclinical stage product candidate, and plans to expand its PDC chemotherapeutic pipeline through both in-house and collaborative R&D efforts. For more information please visit www.cellectar.com.

• Cellectar Biosciences