Madison, WI (Press Release) – Cellectar Biosciences, Inc. (Nasdaq:CLRB), an on­col­ogy-focused, clin­i­cal stage bio­technology com­pany (the "company"), to­day an­nounces its lead PDC com­­pound, CLR 131 has achieved a median over­all sur­vival of 22.5 months to date after a single dose in­fusion of 12.5mCi/m² in patients with mul­ti­ple myeloma. Patients in the first cohort of the com­pany's Phase 1 clin­i­cal trial had an average of 5.8 prior lines of treat­ment and there­fore were con­sidered to be heavily pre­treated.

It is im­por­tant to note that the trial remains on­go­ing, and the over­all sur­vival could con­tinue to in­­crease over time. While there have been no head-to-head stud­ies, for comparison, this on­go­ing over­all sur­vival length from the com­pany's Phase 1 clin­i­cal trial exceeds historic pub­lished out­comes of cur­rently mar­keted sec­ond and third line treat­ment modalities for mul­ti­ple myeloma.

Phase 1 Clinical Trial Results

The fourth cohort of the com­pany's Phase 1 clin­i­cal trial of CLR 131 in mul­ti­ple myeloma is fully en­rolled. Patients in this cohort re­ceived a single in­fusion providing a dose of 31.25 mCi/m², and Cellectar ex­pec­ts to report initial results from this cohort by the close of the third quarter 2017, in line with pre­vi­ous guidance. In addi­tion to the patients from the first cohort achieving a median over­all sur­vival (mOS) of 22.5 months to date, patients from the sec­ond and third cohorts (who re­ceived single doses of 18.75 mCi/m² and 25 mCi/m²) have ex­peri­enced mOS of 13.2 months and 6.7 months, re­spec­tive­ly. As with Cohort One, these cohorts remain on­go­ing and the over­all sur­vival could con­tinue to in­­crease over time. As a result, the com­pany con­tinues to collect over­all sur­vival data on all evaluable trial par­tic­i­pants and will provide timely up­dates, as appro­pri­ate.

NCI-Supported Phase 2 Trial

The com­pany's Phase 2 study of CLR 131 in mul­ti­ple myeloma and other hema­to­logic malig­nan­cies was ini­ti­ated on March 30, 2017 and remains actively en­rolling. The study is being con­ducted at approx­i­mately 10-15 cancer centers in the United States for patients with a variety of orphan-designated relapse or re­frac­tory hema­to­logic cancers. The study's pri­mary end­point is clin­i­cal benefit rate (CBR), with addi­tional end­points of over­all re­sponse rate (ORR), pro­gres­sion free sur­vival (PFS), median over­all sur­vival (mOS) and other markers of ef­fi­cacy fol­low­ing a single in­fusion of CLR 131 providing a dose of 25.0 mCi/m², with the op­tion for a sec­ond 25.0 mCi/m² dose approx­i­mately 75-180 days later.

The hema­to­logic cancers studied in the trial in­clude mul­ti­ple myeloma (MM), chronic lym­pho­cytic leukemia / small lym­pho­cytic lym­phoma (CLL/SLL), lym­pho­plas­ma­­cytic lym­phoma (LPL), marginal zone lym­phoma (MZL), mantle cell lym­phoma (MCL), and poten­tially diffuse large B-cell lym­phoma (DLBCL).

In addi­tion to the CLR 131 in­fusion(s), MM patients will re­ceive 40 mg oral dexa­metha­sone weekly for up to 12 weeks. Efficacy re­sponses will be de­ter­mined by the latest Inter­na­tional Multiple Myeloma Work­ing Group criteria. Efficacy for all lym­phoma patients will be de­ter­mined ac­cord­ing to Lugano criteria.

More in­­for­ma­tion about the trial, in­­clud­ing eligibility re­quire­ments, can be found at www.clinicaltrials.gov, reference NCT02952508.

"We con­tinue to make meaningful progress on our CLR 131 pro­gram and are en­cour­aged by the observed clin­i­cal out­comes to date. We look for­ward to reporting data from the fourth cohort of our Phase 1 trial as well as the single and multi-dose Phase 2 study when avail­able," said Jim Caruso, pres­i­dent and CEO of Cellectar Biosciences. "We also con­tinue to make progress eval­u­ating the clin­i­cal utility of CLR 131 in both liquid and solid tumor orphan designated cancers that have poten­tial for ac­cel­er­ated regu­la­tory path­ways."

About CLR 131

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 (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 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.

Source: Cellectar Biosciences.