• Results dem­onstrated 50% partial re­sponse rate, 50% minimal re­sponse rate, and 100% dis­ease con­trol rate
• Independent Data Monitoring Com­mit­tee de­ter­mines dose to be safe and well tol­er­ated and rec­om­mends study con­tinue to Cohort 7

Florham Park, NJ (Press Release) – Cellectar Biosciences, Inc. (NASDAQ: CLRB), a clin­i­cal-stage bio­pharma­ceu­tical com­pany focused on the discovery, devel­op­ment and com­mer­cial­iza­tion of drugs for the treat­ment of cancer, to­day an­nounced initial results from Cohort 6 in the Com­pany’s on­go­ing Phase 1 clin­i­cal study with CLR 131 in Re­lapsed or Re­frac­tory Multiple Myeloma (R/R MM). The 37.5 mCi/m² frac­tion­ated dose was de­ter­mined to be safe and tol­er­able by the in­de­pen­dent Data Monitoring Com­mit­tee (DMC). Following the deter­mi­na­tion, the Com­pany has ini­ti­ated a Cohort 7 uti­liz­ing a 40 mCi/m² frac­tion­ated dose (20 mCi/m² dose on day 1 and day 8).

Data from Cohort 6 showed im­proved ef­fi­cacy and a clear dose re­sponse com­pared to prior cohorts, in­­clud­ing a 50% partial re­sponse rate, a 50% minimal re­sponse rate and 100% dis­ease con­trol rate. The Inter­na­tional Myeloma Work­ing Group defines a partial re­sponse as a 50% to 89.9% re­duc­tion in the marker of dis­ease and minimal re­sponse as 25% to 49.9% re­duc­tion in the marker of dis­ease. One patient achieving a minimal re­sponse with a 48% re­duc­tion in their marker is still on study and con­tinues to be eval­u­ated.

“We are very pleased to see con­tinued pos­i­tive safety and tol­er­a­bil­ity data in addi­tion to en­hanced ef­fi­cacy from our on­go­ing Phase 1 dose escalation study for CLR 131,” said James Caruso, pres­i­dent and CEO of Cellectar. “We are observing a clear dose re­sponse with greater and more pro­longed median re­duc­tions in surrogate ef­fi­cacy markers through­out the study safety evaluation period as com­pared to prior cohorts, along with an im­proved over­all drug profile with our frac­tion­ated dosing regi­men. The Data Monitoring Com­mit­tee unanimously agreed the study should progress to a Cohort 7 with a higher 40 mCi/m² frac­tion­ated dose. This cohort has been ini­ti­ated with data ex­pec­ted in Q4 2019.”

About the Phase 1 R/R MM Trial

The Phase 1 multi­center, open-label, dose-escalation study is de­signed to eval­u­ate the safety and tol­er­a­bil­ity of CLR 131 admin­istered as a 30-minute IV in­fusion, either as a single bolus dose or as two frac­tion­ated doses, in patients with R/R MM. All doses to date have been deemed safe and well tol­er­ated by an in­de­pen­dent Data Monitoring Com­mit­tee (DMC). Based on the data and the recom­men­da­tion of the DMC, the Com­pany is initiating a Cohort 7 where patients will re­ceive 40 mCi/m² frac­tion­ated dose of CLR 131.

About CLR 131

CLR 131 is a small-molecule, cancer-targeting radiotherapeutic PDC de­signed to de­liver cytotoxic radi­a­tion directly and sel­ectively to cancer cells and cancer stem cells. CLR 131 is the Com­pany’s lead thera­peutic PDC prod­uct can­di­date and is cur­rently being eval­u­ated in both Phase 2 and Phase 1 clin­i­cal stud­ies. In De­cem­ber 2014, the FDA granted orphan drug desig­na­tion for CLR 131 for the treat­ment of mul­ti­ple myeloma. In 2018, the FDA granted orphan drug and rarepedi­atric dis­ease desig­na­tions for CLR 131 for the treat­ment of neu­ro­blas­toma, rhab­do­myo­sar­coma, Ewing’s sarcoma and osteo­sar­coma. In addi­tion to the on­go­ing Phase 1 dose-escalation study and the Phase 2 CLOVER-1 trial, the com­pany recently ini­ti­ated a Phase 1 open-label, dose-escalating study inpedi­atric solid tumors and lym­phoma to eval­u­ate the safety and tol­er­a­bil­ity of a single in­tra­venous admin­istra­tion of CLR 131 in up to 30 chil­dren and adolescents with cancers in­­clud­ing neu­ro­blas­toma, sarcomas, lym­phomas (including Hodgkin’s lym­phoma) and malignant brain tumors.

About Cellectar Biosciences, Inc.

Cellectar Biosciences is focused on the discovery, devel­op­ment, and com­mer­cial­iza­tion of drugs for the treat­ment of cancer. The com­pany plans to de­vel­op pro­pri­e­tary drugs in­de­pen­dent­ly and through re­search and devel­op­ment (R&D) col­lab­o­rations. The core drug devel­op­ment strat­e­gy is to leverage its PDC plat­form to de­vel­op thera­peutics that spe­cif­i­cally target treat­ment to cancer cells. Through R&D col­lab­o­rations, Cellectar seeks to gen­er­ate near-term capital, supple­ment in­ternal resources, gain access to novel mol­e­cules or pay­loads, ac­cel­er­ate prod­uct can­di­date devel­op­ment and to broaden our pro­pri­e­tary and part­nered prod­uct pipe­lines.

The com­pany’s lead PDC thera­peutic, CLR 131, is in a Phase 2 clin­i­cal study (CLOVER-1) in R/R MM and select B-cell malig­nan­cies, as well as a dose escalation Phase 1 study in patients with R/R MM. The com­pany has ini­ti­ated a Phase 1 study with CLR 131 inpedi­atric solid tumors and lym­phoma.

Cellectar’s prod­uct pipe­line also in­cludes one pre­clin­i­cal PDC chemo­ther­a­peu­tic pro­gram (CLR 1900) and sev­er­al part­nered PDC assets.

For more in­for­ma­tion, please visit www.cellectar.com.

Forward-Looking State­ment Disclaimer

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 disruptions at our sole source supplier of CLR 131, 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, the volatile mar­ket for priority review vouchers, 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, 2018. 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.