• 30% over­all re­sponse­ rate seen with an average pro­gres­sion free sur­vival of 4.5 months and an ac­ceptable and ex­pec­ted safety profile
• Additional data in patients re­ceiv­ing higher frac­tion­ated doses of CLR 131 antic­i­pated in Jan­u­ary­

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 summary data from 20 patients re­ceiv­ing a single dose of CLR 131 in its Phase 2 CLOVER-1 trial in select re­lapsed / re­frac­tory (RR) B-cell malig­nan­cies. The com­pany had pre­vi­ously an­nounced data from 10 mul­ti­ple myeloma patients re­ceiv­ing a single dose of CLR 131 in Feb­ru­ary 2019, which showed a 30% over­all re­sponse­ rate (ORR).

The Phase 2 CLOVER-1 study is de­signed to identify a safe and efficacious dose and regi­men to be used in a pivotal study for select hema­to­logic in­di­ca­tions. The 20 eval­u­ated patients, in­cluded 10 subjects with re­lapsed / re­frac­tory mul­ti­ple myeloma, and 10 with re­lapsed / re­frac­tory B-cell lym­phoma. The median age was 71 (range 52-82), in­clud­ing 7 females and 13 males, with a median of 6 prior sys­temic ther­a­pies for mul­ti­ple myeloma and 4 for patients with lym­phoma. Eight patients had prior au­tol­o­gous stem cell trans­plant ther­apy. Data from these 20 patients showed a 30% ORR, a 75% clin­i­cal benefit rate, an average pro­gres­sion free sur­vival of 4.5 months and an ac­ceptable and ex­pec­ted safety profile.

“The 30% ORR seen sug­gests that CLR 131 treat­ment at the single 25 mCi/m² bolus dose may have ac­­tiv­ity in these heavily pre-treated patients,” said James Caruso, pres­i­dent and CEO of Cellectar Biosciences. “We recently pre­sented data at ASH on 19 patients with re­lapsed, re­frac­tory mul­ti­ple myeloma, which showed im­proved ef­fi­cacy and safety with frac­tion­ated doses vs. the single bolus dose, and patients re­ceiv­ing a frac­tion­ated dose of 37.5mCi showed a 50% ORR. As back­ground, recently approved drugs for this in­di­ca­tion have dem­onstrated approx­i­mate ORRs of 25% in a similar patient pop­u­la­tion and up to 29% as a third line treat­ment. We plan to provide addi­tional data in patients who are re­ceiv­ing higher frac­tion­ated doses of CLR 131 in Jan­u­ary­.”

The pri­mary adverse events (AEs) seen were cytopenias, in­clud­ing thrombo­cyto­penia, anemia, neu­tro­penia, and de­creased white blood cell count. The hema­to­logic AEs were ex­pec­ted, man­ageable and followed a predictable timeline to nadir (average 49 days) and sub­se­quent re­cov­ery (average 16 days post nadir). Patients with dis­ease in the bone mar­row ex­peri­enced more cytopenias than did patients with no detectable dis­ease in the bone mar­row. All patients recovered from the cytopenias.

About the Phase 2 CLOVER-1 Trial

CLOVER-1 is a Phase 2 study of CLR 131 being con­ducted in approx­i­mately 10 lead­ing cancer centers in the United States in patients with re­lapsed or re­frac­tory B-cell hema­to­logic cancers. The hema­to­logic cancers being 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 diffuse large B-cell lym­phoma (DLBCL).

The study will en­roll up to 80 patients. Its pri­mary end­point is clin­i­cal benefit re­sponse­ (CBR), with addi­tional end­points of over­all re­sponse­ rate (ORR), pro­gres­sion free sur­vival (PFS), median over­all sur­vival (OS) and other markers of ef­fi­cacy fol­low­ing a frac­tion­ated dose of 37.575mCi/m² of CLR 131 admin­istered in two 30-minute in­fusions of 18.75mCi/m² of CLR 131 admin­istered on day 1 and day 7 (± 1), with the op­tion for a sec­ond dose cycle approx­i­mately 75-180 days later. The com­pany ex­pec­ts to report top­line data in 2019.

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

About CLR 131

CLR 131 is a small-molecule, cancer-targeting radiotherapeutic Phospholipid Drug ConjugateTM (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. The FDA granted orphan drug desig­na­tion for CLR 131 for the treat­ment of mul­ti­ple myeloma as well as orphan drug and rare pedi­atric 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 in pedi­atric 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 is devel­op­ing pro­pri­e­tary drugs in­de­pen­dent­ly and through re­search and devel­op­ment (R&D) col­lab­o­rations. The com­pany’s core objective is to leverage its pro­pri­e­tary Phospholipid Drug ConjugateTM (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 three clin­i­cal stud­ies – a Phase 2 study, and two Phase 1 stud­ies. The Phase 2 clin­i­cal study (CLOVER-1) is in re­lapsed / re­frac­tory (R/R) B-cell malig­nan­cies, in­clud­ing mul­ti­ple myeloma (MM), chronic lym­pho­cytic leukemia / small lym­pho­cytic lym­phoma (CLL/SLL), lym­pho­plas­ma­­cytic lym­phoma (LPL), marginal zone lym­phoma (MZL), mantle cell lym­phoma (MCL), and diffuse large B-cell lym­phoma (DLBCL). The com­pany is also con­ducting a Phase 1 dose escalation study in patients with R/R mul­ti­ple myeloma (MM) and a Phase 1 study in pedi­atric solid tumors and lym­phoma.

The com­pany’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 or join the conversation by liking and fol­low­ing us on our 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. 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 and Form 10-Q for the quarters ended March 31, 2019, June 30, 2019 and Sep­tem­ber 30, 2019. 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.