40% over­all re­sponse rate (ORR) with a total admin­istered dose of 60 mCi or greater

Forham 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 that a clin­i­cally meaningful 40% over­all re­sponse rate (ORR) was ob­served in the subset of re­frac­tory mul­ti­ple myeloma patients deemed triple class re­frac­tory who re­ceived a total admin­istered dose of 60 mCi or greater. Triple class re­frac­tory is defined as patients re­frac­tory to immuno­modu­la­tory, pro­te­a­some in­hib­i­tors and anti-CD38 anti­body drug classes.

The 40% ORR (6/15 patients) rep­re­sents triple class re­frac­tory patients en­rolled in Part A of Cellectar’s CLOVER-1 study and addi­tional patients en­rolled in Part B from March through May 2020. As a reminder, all patients being en­rolled in Part B are re­quired to be triple class re­frac­tory. The addi­tional six patients were heavily pre-treated with an average of 9 prior multi-drug regi­mens. Three patients re­ceived a total admin­istered dose of greater than 60 mCi and three re­ceived less than 60 mCi. Consistent with the data re­leased in Feb­ru­ary 2020, patients re­ceiv­ing greater than 60 mCi exhibit strong re­sponses. Patients con­tinue to tolerate CLR 131 well, with the most common and almost ex­clu­sive treat­ment emergent ad­verse events being cytopenias and im­por­tantly, no un­ex­pected ad­verse events have been re­ported.

“We re­main en­cour­aged by the con­sistency of CLR 131’s ef­fi­cacy and tol­er­a­bil­ity data in these ex­treme­ly chal­leng­ing to treat triple class re­frac­tory mul­ti­ple myeloma patients,” said Dr. John Friend, CMO of Cellectar Bio­sciences. “A 40% ORR is a clin­i­cally meaningful out­come. For reference pur­poses, two recently ap­prov­ed drugs re­ceived a 25% and 31% ORR in triple class re­frac­tory patients. We look for­ward to the fur­ther de­vel­op­ment of CLR 131, a first in class phos­pho­lipid radio con­ju­gate that may provide a sig­nif­i­cant ben­e­fit to patients and treat­ment alter­na­tive for clinicians."

About CLOVER-1

The Phase 2 CLOVER-1 study is an open-label study de­signed to de­ter­mine the ef­fi­cacy and safety of CLR 131 in select B-cell malig­nan­cies. The CLOVER-1 Phase 2 study com­pleted the Part A dose-exploration portion, con­ducted in re­lapsed / re­frac­tory (r/r) B-cell malig­nan­cies, and is now en­rolling in the Part B ex­pan­sion cohorts eval­u­ating ≥ 60 mCi total body dose and 2 cycle doses as patients have dem­onstrated a clin­i­cally meaningful re­sponse and predictable safety profile of CLR 131 in r/r mul­ti­ple myeloma (MM) and lym­pho­plas­ma­­cytic lym­phoma/Waldenstrom’s macro­glob­u­lin­emia (LPL/WM). Patients with LPL/WM must have re­ceived at least two prior treat­ment regi­mens, unless in­eli­gible to re­ceive stan­dard agents, and have measurable dis­ease, as defined by either a nodal lesion of >15 mm, an extranodal lesion of >10 mm, or measurable IgM. Prior ex­ternal beam radi­a­tion ther­apy was allowed. The median age of the four LPL/WM patients en­rolled in the study was 70 (range 54-81) and in­cluded 2 females and 2 males who had a median of two prior regi­mens (range 1-5). CLR 131 was admin­istered in­tra­venously, up to 30 min­utes.

Cellectar was awarded approx­i­mately $2 mil­lion in non-dilutive grant fund­ing from the National Cancer In­sti­tute to help fund the study. More in­for­ma­tion about the study, in­clud­ing eligibility re­quire­ments, can be found at www.clinicaltrials.gov, reference NCT02952508.

About CLR 131

CLR 131 is a small-molecule Phospholipid Drug Conjugate™ de­signed to provide targeted de­livery of iodine-131 (radioisotope) directly to can­cer cells, while limiting exposure to healthy cells unlike many traditional on-market treat­ment op­tions. CLR 131 is the com­pany’s lead prod­uct can­di­date and is cur­rently being eval­u­ated in a Phase 2 study in B-cell lym­phomas, and a Phase 1 dose-escalating clin­i­cal study in pedi­atric solid tumors and lym­phomas. The com­pany recently com­pleted a Phase 1 dose-escalation clin­i­cal study in r/r mul­ti­ple myeloma. The FDA granted CLR 131 Fast Track Desig­na­tion for both r/r mul­ti­ple myeloma and r/r diffuse large B-cell lym­phoma and Orphan Drug Desig­na­tion (ODD) for the treat­ment of mul­ti­ple myeloma, lym­pho­plas­ma­­cytic lym­phoma/Waldenstrom’s macro­glob­u­lin­emia, neu­ro­blas­toma, rhab­do­myo­sar­coma, Ewing’s sarcoma and osteo­sar­coma. CLR 131 was also granted Rare Pediatric Disease Desig­na­tions for the treat­ment of neu­ro­blas­toma, rhab­do­myo­sar­coma, Ewing’s sarcoma and osteo­sar­coma. Earlier this year, the Euro­pean Com­mis­sion granted an ODD for r/r mul­ti­ple myeloma and most recently, the U.S. Food and Drug Admin­istra­tion granted Fast Track Desig­na­tion for CLR 131 in lym­pho­plas­ma­­cytic lym­phoma (LPL)/Waldenstrom’s macro­glob­u­lin­emia (WM) in patients having re­ceived two prior treat­ment regi­mens or more.

About Cellectar Bio­sciences, Inc.

Cellectar Bio­sciences is focused on the dis­cov­ery, de­vel­op­ment and com­mer­cial­i­za­tion of drugs for the treat­ment of can­cer. The com­pany is devel­op­ing pro­pri­e­tary drugs in­de­pen­dent­ly and through re­search and de­vel­op­ment col­lab­o­rations. The com­pany’s core objective is to le­ver­age its pro­pri­e­tary Phospholipid Drug Conjugate™ (PDC) de­livery plat­form to de­vel­op PDCs that spe­cif­i­cally target can­cer cells, de­livering im­proved ef­fi­cacy and better safety as a re­­sult of fewer off-target effects. The com­pany’s PDC plat­form possesses the po­ten­tial for the dis­cov­ery and de­vel­op­ment of the next-gener­a­tion of can­cer-targeting treat­ments, and it plans to de­vel­op PDCs in­de­pen­dent­ly and through re­search and de­vel­op­ment col­lab­o­rations.

The com­pany’s lead PDC thera­peutic, CLR 131, is cur­rently in two clin­i­cal stud­ies. The CLOVER-1 Phase 2 study com­pleted the Part A dose-exploration portion, con­ducted in re­lapsed / re­frac­tory (r/r) B-cell malig­nan­cies, and is now en­rolling in the Part B ex­pan­sion cohorts eval­u­ating a two cycle dosing regi­men that provides approx­i­mately 100 mCi total body dose of CLR 131 in r/r mul­ti­ple myeloma (MM) and lym­pho­plas­ma­­cytic lym­phoma/Waldenstrom’s macro­glob­u­lin­emia (LPL/WM). The data from the Part A portion was an­nounced on Feb­ru­ary 19, 2020.

The Phase 1 pedi­atric study is an open-label, sequential-group, dose-escalation study to eval­u­ate the safety and tol­er­a­bil­ity of CLR 131 in chil­dren and adolescents with re­lapsed or re­frac­tory can­cers, in­clud­ing malignant brain tumors, neu­ro­blas­toma, sarcomas, and lym­phomas (including Hodgkin’s lym­phoma). The Phase 1 study is being con­ducted inter­na­tionally at seven lead­ing pedi­atric can­cer centers.

The com­pany’s prod­uct pipe­line in­cludes one pre­clin­i­cal PDC chemo­ther­a­peu­tic pro­gram (CLR 1900) and mul­ti­ple part­nered PDC assets.

For more in­for­ma­tion, please visit www.cellectar.com or join the con­ver­sa­tion by liking and fol­low­ing us on the com­pany’s social media channels: Twitter, LinkedIn, and Face­book.

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 in­clud­ing our ex­pec­ta­tions of the im­pact of the recent COVID-19 pan­dem­ic. 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, patient en­roll­ment and the com­ple­tion of clin­i­cal stud­ies, the FDA re­view process and other gov­ern­ment reg­u­la­tion, our ability to main­tain orphan drug desig­na­tion in the United States for CLR 131, 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, 2019 and our Form 10-Q for the quarters ended March 31, 2020 and June 30, 2020. These for­ward-looking state­ments are made only as of the date hereof, and we disclaim any obli­ga­tion to up­date any such for­ward-looking state­ments. 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.