Cellectar Biosciences, Inc.: Initiates proof-of-concept trial of I-131-CLR1404 in multiple myeloma

MADISON, Wis., April 15, 2015 (GLOBE NEWSWIRE) — Cellectar
Biosciences, Inc. (Nasdaq:CLRB), a clinical stage biopharmaceutical
company developing innovative agents for the detection and treatment of
cancer, announced the initiation of patient dosing in a
proof-of-concept trial of I-131-CLR1404 in patients with relapsed or
refractory multiple myeloma, an indication for which I-131-CLR1404
previously received orphan drug designation from the U.S. Food and Drug

Multiple myeloma is an incurable malignancy for which novel therapies
are needed. The radiosensitivity of multiple myeloma is well
documented. I-131-CLR1404 is designed to allow for targeted delivery of
ionizing radiation to malignant cells, allowing for an intracellular
radiation mechanism of cancer cell killing regardless of anatomic

“We are excited to be developing a new treatment option for this
difficult disease. Because of its unique mechanism of action,
I-131-CLR1404 may represent an entirely different treatment approach
for patients that are no longer responding to currently available
therapies,” commented Dr. Natalie Callander, principal investigator of
Cellectar’s I-131-CLR1404 multiple myeloma trial, Associate Professor
of Medicine, and Director, University of Wisconsin Carbone Cancer
Center Myeloma Clinical Program. “I-131-CLR1404 appears to be a
promising investigational drug and pre-clinical data indicate that the
combination of Cellectar’s cancer-selective delivery and retention
platform with a known radiotherapeutic could be highly effective in
treating multiple myeloma. We look forward to working with Cellectar
and other investigators to explore the potential of I-131-CLR1404 as a
treatment for relapsed or refractory multiple myeloma.”

This is a multi-center, open-label, sequential group, dose escalation,
Phase I proof-of-concept study evaluating the safety and tolerability
of I-131-CLR1404, with and without concurrent weekly dexamethasone, in
multiple myeloma patients who have previously been treated with, or are
intolerant of, an immunomodulator and a proteasome inhibitor. The
secondary objectives of the study are to identify a recommended Phase
II dose and assess therapeutic activity of I-131-CLR1404 in relapsed or
refractory multiple myeloma. Therapeutic activity will be assessed by
overall response rate, time to progression and duration of response.

Patients will be enrolled into cohorts that receive escalating single
doses of I-131-CLR1404 combined with a set dose of dexamethasone. The
first cohort of subjects will receive a 12.5 mCi/m2 dose of
I-131-CLR1404. A minimum of three subjects will be enrolled at each
dose level. Dose escalation and level expansion will be guided by
safety and will be performed after all subjects in a cohort have been
followed for 12 weeks. Following identification of the highest
tolerated dose, additional I-131-CLR1404-naive subjects will be
enrolled and treated with the identified dose of I-131-CLR1404 without
concurrent oral dexamethasone.

“I-131-CLR1404 has been generally well tolerated in patients and we
believe that its selectivity and potency provide a solid rationale for
its use in multiple myeloma,” said Dr. Simon Pedder, president and
chief executive officer of Cellectar Biosciences. “Based on results
from our Phase I trials and the radiosensitivity of multiple myeloma,
we believe 12.5 mCi/m2 is a meaningful starting dose of I-131-CLR1404
and evidence of clinical activity will be assessable relatively early
in the dose escalation process.”

About Multiple Myeloma

Multiple myeloma is a form of blood cancer that primarily affects older
adults and arises from plasma cells in the bone marrow. According to
the National Cancer Institute, multiple myeloma is the second most
common blood cancer in the United States and constitutes approximately
1 percent of all cancers. The National Cancer Institute estimates that
24,500 Americans were diagnosed with multiple myeloma in 2014 and
approximately 11,000 myeloma patients die each year.

About I-131-CLR1404

I-131-CLR1404 is a small-molecule, broad-spectrum, cancer-targeted
radiopharmaceutical comprised of a proprietary optimized phospholipid
ether (PLE) analog, acting as a cancer-targeted delivery and retention
vehicle, covalently labeled with iodine-131, a cytotoxic radioisotope
that is already commonly used to treat thyroid and other cancer types.
I-131-CLR1404 is engineered to combine an intracellular radiation
mechanism of cancer cell killing with targeted delivery to a wide range
of malignant tumor types. Preclinical models have also demonstrated
selective uptake and retention in cancer stem cells, suggesting the
potential for longer lasting cancer remission. I-131-CLR1404 has been
granted orphan drug designation from the U.S. Food and Drug
Administration for the treatment of multiple myeloma.

About Cellectar Biosciences, Inc.

Cellectar Biosciences is developing agents to detect, treat and monitor
a broad spectrum of cancers. Using a novel phospholipid ether analog
(PLE) platform technology as a targeted delivery and retention vehicle,
Cellectar’s compounds are designed to be selectively taken up and
retained in cancer cells including cancer stem cells. With the ability
to attach both imaging and therapeutic agents to its proprietary
delivery platform, Cellectar has developed a portfolio of product
candidates engineered to leverage the unique characteristics of cancer
cells to “find, treat and follow” malignancies in a highly selective
way. I-124-CLR1404 is a small-molecule, broad-spectrum, cancer-targeted
PET imaging agent currently being evaluated in a Phase II glioblastoma
imaging trial. Additionally, multiple investigator-sponsored Phase I/II
clinical trials are ongoing across 11 solid tumor indications.
I-131-CLR1404 is a small-molecule, broad-spectrum, cancer-targeted
molecular radiotherapeutic that delivers cytotoxic radiation directly
and selectively to cancer cells including cancer stem cells. A Phase Ib
dose-escalation trial of I-131-CLR1404 in patients with advanced solid
tumors was completed in the first quarter of 2014 and results presented
at the American Society of Clinical Oncology (ASCO) 2014 Annual
Meeting. CLR1502 is a preclinical, cancer-targeted, non-radioactive
optical imaging agent for intraoperative tumor margin illumination and
non-invasive tumor imaging. For additional information please visit

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