Full Press Release Details
Cellectar Biosciences Introduces
Multiple Dose Regimen In Fifth Cohort of Phase 1 Trial of CLR 131 in Multiple Myeloma
Wisc. (October 24, 2017) -- Cellectar Biosciences, Inc.
(Nasdaq: CLRB), an oncology-focused, clinical stage biotechnology company (the "company"), today
announces the design of the multiple dose fifth cohort of its Phase I dose escalation safety trial of lead PDC
compound, CLR 131, in relapse or refractory multiple myeloma. Cohort 5 will utilize
two 15.625 mCI/m2 doses given one week apart with the total combined dose equaling 31.25 mCi/m2, the same
total dose provided to patients that resulted in a partial response in Cohort 4. In previous cohorts, CLR 131 was given in a single
In September, the trial's Data Monitoring
Committee (DMC) determined that the fourth cohort single dose of 31.25 mCi/m2 was safe and tolerated. In addition, the
DMC determined that the use of a split, or repeat dose might be advantageous. Given internal company data and recently announced
results of preclinical studies in which 2 doses of CLR 131 demonstrated a statistically significant improvement in survival benefits
and reduction of tumor volume in multiple mouse models (April 27, 2017), the company has enhanced the study's protocol such
that subsequent cohorts will include repeat dosing.
"Given the encouraging results we've
observed to date in previous cohorts, we hope to see similar, or perhaps even improved safety results in this arm of the trial,"
said Natalie Callander, M.D., professor of medicine, director, University of Wisconsin Carbone Cancer Center Myeloma Clinical Program,
and the study's lead investigator. "Previous participants have asked us if it was possible to receive additional doses,
as this therapy has been so well tolerated."
Patients participating in the fifth
cohort will receive a total of two doses of CLR 131 as 30-minute infusions on their first and seventh days. They will then be evaluated
over the course of 85 days to determine the safety and efficacy of the treatment as per the study protocol. During the previous
cohort, one of three evaluable patients experienced a partial response to treatment with CLR 131, while the other two achieved
stable disease. All Cohort 4 patients had heavily pretreated relapsed or refractory multiple myeloma (greater than five prior lines)
and high degree of tumor burden upon entry into the trial, and the company expects to recruit similar trial subjects for Cohort
5. Despite the challenging patient population enrolled to date, 89 percent of all Phase 1 patients achieved a clinical benefit
"This fifth cohort represents
an important opportunity to better understand the clinical utility of a split dose regimen and to further explore the safety and
efficacy of CLR 131. Utilizing two doses provides an opportunity to increase the total amount of drug delivered to the patients
which could result in an improvement in efficacy while maintaining similar or better safety profile," said Jim Caruso, president
and CEO of Cellectar Biosciences. "Clinical assessment, along with the improved benefits demonstrated by two doses in preclinical
studies, suggest to us that the protocol changes should enhance our chances to see improved patient outcomes in this and future
CLR 131 is an investigational
compound under development for a range of hematologic malignancies. It is currently being evaluated as a single-dose treatment
in a Phase 1 clinical trial in patients with relapsed or refractory (R/R) multiple myeloma (MM) as well as in a Phase 2 clinical
trial for R/R MM and select R/R lymphomas with either a one- or two-dose treatment. CLR 131 represents a novel approach to treating
hematological diseases and based upon preclinical and interim Phase 1 study data may provide patients with therapeutic benefits
including, overall survival, an improvement in progression-free survival, and overall quality of life. CLR 131 utilizes the company's
patented PDC tumor targeting delivery platform to deliver a cytotoxic radioisotope, iodine-131, directly to tumor cells.
The FDA has granted Cellectar an orphan drug designation for CLR 131 in the treatment of multiple myeloma.
About Phospholipid Drug Conjugates
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 designed its phospholipid ether (PLE) carrier platform to be coupled with a variety of payloads to
facilitate the discovery and development of improved targeted novel therapeutic compounds. 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 (Nasdaq: CLRB) 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, even sites of metastases. The company's lead therapeutic PDC,
CLR 131, utilizes iodine-131, a cytotoxic radioisotope, as its payload. CLR 131 has been designated as an orphan drug by the US
FDA and is currently being evaluated in a Phase 1 clinical study in patients with relapsed or refractory multiple myeloma and
a Phase 2 clinical study to assess efficacy in a range of B-cell malignancies. The company is also developing proprietary PDCs
for targeted delivery of chemotherapeutics and has several preclinical stage product candidates, 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.
This news release contains forward-looking statements. You can
identify these statements by our use of words such as "may," "expect," "believe," "anticipate,"
"intend," "could," "estimate," "continue," "plans," or their negatives or cognates.
These statements are only estimates and predictions and are subject to known and unknown risks and uncertainties that may cause
actual future experience and results to differ materially from the statements made. These statements are based on our current beliefs
and expectations as to such future outcomes. Drug discovery and development involve a high degree of risk. Factors that might cause
such a material difference include, among others, uncertainties related to the ability to raise additional capital, uncertainties
related to the ability to attract and retain partners for our technologies, the identification of lead compounds, the successful
preclinical development thereof, the completion of clinical trials, the FDA review process and other government regulation, our
pharmaceutical collaborators' ability to successfully develop and commercialize drug candidates, competition from other pharmaceutical
companies, product pricing and third-party reimbursement. A complete description of risks and uncertainties related to our business
is contained in our periodic reports filed with the Securities and Exchange Commission including our Form 10-K for the year ended
December 31, 2016. These forward-looking statements are made only as of the date hereof, and we disclaim any obligation to
update any such forward-looking statements.