• 42.8% ORR in mul­ti­ple myeloma at the 75mCi total body dose
• 42.0% ORR and 11% CRR in all non-Hodgkin’s lym­phoma (NHL) patients
• 100% ORR seen in Lymphoplasmacytic Lymphoma / Waldenstrom’s Macro­globu­linemia (LPL / WM) patients
• 76.7% of the mul­ti­ple myeloma patients across all doses tested ex­peri­enced tumor re­duc­tion with a strong dose re­sponse­

{{image}}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 pos­i­tive data from its Phase 2 CLOVER-1 study in patients with re­lapsed / re­frac­tory B-cell lym­phomas. Addi­tionally, the com­pany an­nounced the suc­cess­ful com­ple­tion of its Phase 1 dose escalation study. Data from the stud­ies dem­onstrated ac­­tiv­ity in all in­di­ca­tions tested: mul­ti­ple myeloma (MM), diffuse large B-cell lym­phoma (DLBCL), chronic lym­pho­cytic leukemia / small lym­pho­cytic lym­phoma (CLL / SLL), marginal zone lym­phoma (MZL), mantle cell lym­phoma (MCL), and lym­pho­plas­ma­­cytic lym­phoma/Waldenstrom’s macro­globu­linemia (LPL/WM).

CLR 131 achieved notable re­sponse­ rates in patients with mul­ti­ple myeloma - 34.5% over­all re­sponse­ rate (ORR) over all thera­peutic doses (n=33), and non-Hodgkin’s lym­phoma (NHL) - 42% ORR over all doses (n=20) while main­taining a well-tolerated safety profile across all patients. Based upon these pos­i­tive re­­sults and corroborating data showing the poten­tial to fur­ther im­prove upon cur­rent over­all re­sponse­ rates and durability of those re­sponse­s, the study has been ex­panded to test a two-cycle dosing optimization regi­men of CLR 131.

Patients in the stud­ies were heavily pre-treated, with mul­ti­ple myeloma patients having a median of five prior treat­ment regi­mens (range: 3 to 17), which in­cluded immuno­modu­la­tory drugs, pro­te­a­some in­hib­i­tors and CD38 anti­bodies for the majority of patients. Addi­tionally, a majority of the patients (51%) were quad re­frac­tory or greater and 44% of all treated mul­ti­ple myeloma patients were triple class re­frac­tory. NHL patients in the study were also heavily pre-treated, having had a median of 3 prior lines of treat­ment (range, 1 to 9) with the majority of patients being re­frac­tory to ritux­i­mab­ and/or ibrutinib. In both groups, the patients had a median age of 70 with a range of 51 to 86.

Relapsed/refractory mul­ti­ple myeloma patients were treated with three dif­fer­en­t doses (<50mCi, ~50mCi and ~75mCi total body dose (TBD)); the <50mCi total body dose was a deliberately planned sub-therapeutic dose. Patients who re­ceived the highest dose of CLR 131 showed a 42.8% ORR, and those who re­ceived ~50mCi TBD had a 26.3% ORR with 100% of all evaluable patients (n=43) achieving clin­i­cal ben­e­fit (primary out­come measure) as defined by having stable dis­ease or better. 85.7% of mul­ti­ple myeloma patients re­ceiv­ing the higher total body dose levels of CLR 131 ex­peri­enced tumor re­duc­tion. The 75mCi TBD dem­onstrated pos­i­tive ac­­tiv­ity in both high-risk patients and triple class re­frac­tory patients with a 50% and 33% ORR, re­spec­tive­ly.

“The data re­ported to­day are very promising and we be­lieve the prod­uct profile for CLR 131 can im­prove fur­ther with the admin­istra­tion of a sec­ond cycle. These re­­sults are even more impressive con­sidering the chal­leng­ing patient pop­u­la­tion tested, as all were heavily pre-treated with the vast majority being re­frac­tory to their most recent ther­apy,” said James Caruso, pres­i­dent and CEO of Cellectar Bio­sciences. “Based upon these compelling data and the need for new and inno­va­tive treat­ment op­tions for patients, we plan to execute upon a well-defined and approvable regu­la­tory path for­ward in a prioritized hema­to­logic in­di­ca­tion. We hope that this poten­tially first-in-class PLE-targeted radio­thera­peutic will provide a new and meaningful treat­ment op­tion for patients living with mul­ti­ple myeloma and/or NHL.”

The most fre­quently re­ported ad­verse events in re­lapsed / re­frac­tory mul­ti­ple myeloma patients were cytopenias, which followed a predictable course and timeline. The most common grade ≥3 events at the highest dose (75mCi TBD) were hema­to­logic toxicities in­clud­ing thrombo­cyto­penia (65%), neu­tro­penia (41%), leu­ko­penia (30%), anemia (24%) and lymphopenia (35%). No patients ex­peri­enced cardiotoxicities, neurological toxicities, in­fusion site reac­tions, periph­eral neu­rop­athy, allergic reac­tions, cytokine re­lease syn­drome, ker­a­top­a­thy, renal toxicities, or changes in liver enzymes. The safety and tol­er­a­bil­ity profile in patients with re­lapsed / re­frac­tory NHL was the same except for fewer cytopenias of any grade.

In addi­tion to these findings, subtype assess­ments were com­pleted in the r/r B-cell NHL patients. Patients with DLBCL dem­onstrated a 30% re­sponse­ rate with one patient achieving a com­plete re­sponse­ (CR), which con­tinues at nearly 24 months post-treatment. The re­sponse­ rate for CLL / SLL / MZL patients was 33%. Only two mantle cell patients were en­rolled, with stable dis­ease as the best re­sponse­.

Current data from the com­pany’s Phase 2 CLOVER-1 clin­i­cal study show that four LPL/WM patients dem­onstrated 100% ORR with one patient achieving a com­plete re­sponse­ which con­tinues at nearly 27 months. This may rep­re­sent an im­por­tant im­prove­ment in the treat­ment of re­lapsed / re­frac­tory LPL/WM as no ap­prov­ed or late-stage devel­op­ment treat­ments for sec­ond- and third-line patients have re­ported a com­plete re­sponse­. LPL/WM is a rare, indolent and incurable form of non-Hodgkin’s lym­phoma that is com­prised of a niche patient pop­u­la­tion in need of new and better treat­ment op­tions.

“For patients who have failed the cur­rent stan­dard of care treat­ments for any of these in­di­ca­tions, there is a need for addi­tional treat­ment op­tions,” said lead study in­ves­ti­ga­tor Sikander Ailawadhi, M.D., Division of He­ma­tol­ogy/Oncology, De­part­ment of Internal Medicine, Mayo Clinic, Jacksonville, Florida. He added, “These data are impressive, especially in these very dif­fi­cult to treat patient pop­u­la­tions. CLR 131 offers a very attractive safety and ef­fi­cacy profile.”

Summary of Results by Total Body Dose

Conference Call Details

The man­agement team will host a conference call for in­vestors to­day, Wednesday, Feb­ru­ary 19 at 10:30 am Eastern Time to re­view the re­­sults and data from both the Phase 2 CLOVER-1 study and the Phase 1 r/r MM dose escalation study. The call will also in­clude a pre­sen­ta­tion from lead in­ves­ti­ga­tor, Dr. Sikander Ailawadhi, M.D. Conference call, webcast and post-conference call replay details are as follows:

Domestic dial-in: 877-705-6003
International dial-in: 201-493-6725
Conference ID: 13697717
Webcast: http://bit.ly/2uNAGWY

A webcast replay of the event will be avail­able fol­low­ing the live event on the Events section of the Cellectar website.

About the Phase 2 CLOVER-1 Study

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 / re­frac­tory B-cell hema­to­logic can­cers. The hema­to­logic can­cers being studied in­clude mul­ti­ple myeloma (MM), chronic lym­pho­cytic leukemia / small lym­pho­cytic lym­phoma (CLL / SLL), lym­pho­plas­ma­­cytic lym­phoma / Waldenstrom’s macro­globu­linemia (LPL/WM), marginal zone lym­phoma (MZL), mantle cell lym­phoma (MCL), and diffuse large B-cell lym­phoma (DLBCL).

The study could en­roll up to 80 patients with its pri­mary end­point being clin­i­cal ben­e­fit re­sponse­ (CBR), which is defined as the pro­por­tion­ of MM patients within three months fol­low­ing the initial in­fusion of CLR 131 with stringent com­plete re­sponse­, com­plete re­sponse­, very good partial re­sponse­, partial re­sponse­ and stable dis­ease per Inter­na­tional Myeloma Work­ing Group criteria, or the pro­por­tion­ of lym­phomas patients (CLL/SLL, LPL, MZL, MCL, and DLBCL) within three months fol­low­ing the initial in­fusion of CLR 131 with CR, PR and SD per the Lugano classification CT-based re­sponse­ criteria. Addi­tional end­points in­clude over­all re­sponse­ rate (ORR), pro­gres­sion free sur­vival (PFS), median over­all sur­vival (OS) and other markers of ef­fi­cacy. Patients were treated with three dif­fer­en­t doses (<50mCi, ~50mCi and ~75mCi total body dose) admin­istered in either a single 30-minute in­fusion or two 30-minute in­fusions at day 1 and day 7 (± 1), with the op­tion for a sec­ond dose cycle approx­i­mately 75-180 days later.

Based upon pos­i­tive re­­sults and corroborating data showing the poten­tial to fur­ther im­prove upon the cur­rent over­all re­sponse­ rates and durability of those re­sponse­s, the study has been ex­panded to test a two-cycle dosing optimization regi­men of CLR 131. Patients will be admin­istered a two-cycle regi­men with a total of four in­fusions, to be admin­istered on day 1 and day 15 (± 1) and again on day 57 and day 71 (± 1).

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 the Phase 1 r/r MM Dose Escalation Study

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 I.V. in­fusion, either as a single bolus dose or as two frac­tion­ated doses. The r/r mul­ti­ple myeloma patients in this study re­ceived doses ranging from ≤25mCi to ~75mCi total body dose. To date, an in­de­pen­dent Data Monitoring Com­mit­tee de­ter­mined that all doses have been safe and well-tolerated by patients.

About CLR 131

CLR 131 is a small-molecule Phospholipid Drug Conjugate™ de­signed to provide targeted de­livery of iodine-131 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 two Phase 1 dose-escalating clin­i­cal stud­ies, one in mul­ti­ple myeloma and one in pedi­atric solid tumors and lym­phoma. The FDA granted CLR 131 Fast Track Desig­na­tion for both r/r mul­ti­ple myeloma and r/r DLBCL 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. Most recently, the Euro­pean Com­mis­sion granted an ODD for r/r mul­ti­ple myeloma.

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 three clin­i­cal stud­ies - one 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 / Waldenstrom’s macro­globu­linemia (LPL / WM), 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 and a Phase 1 study in pedi­atric solid tumors and lym­phomas.

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 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. 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 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, 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.