Madison, WI (Press Release) – Cellectar Biosciences (Nasdaq: CLRB), a clin­i­cal-stage bio­pharma­ceu­tical com­pany focused on the discovery, devel­op­ment and com­mer­cial­iza­tion of drugs for the treat­ment of cancer, to­day up­dates interim over­all sur­vival (OS) data from the com­pany’s on­go­ing Phase 1b clin­i­cal trial eval­u­ating CLR 131 for the treat­ment of re­lapsed/refractory (R/R) mul­ti­ple myeloma (MM).

The results to date show that OS is cur­rently at 19.4 months. Cellectar con­tinues to monitor these patients and in­tends to up­date OS results as data be­come avail­able. All 15 patients from the Phase 1b, single-dose cohorts were heavily pre­treated, re­ceiv­ing an average of 5 pre­vi­ous lines of multidrug ther­apy in­­clud­ing anti CD38, immunomodulating drugs and pro­te­a­some in­hib­i­tors. All patients were re­lapsed or re­frac­tory to at least one pro­te­a­some in­hib­i­tor and IMiD. Most patients pre­sented with ad­vanced stage 2 or 3 dis­ease and 67% had pre­vi­ously re­ceived at least 1 stem cell trans­plant.

“We are extremely pleased to an­nounce that CLR 131 has achieved OS of 19.4 months in our Phase 1b trial in R/R MM. We view this out­come as impressive con­sidering all patients were heavily pre­treated and pre­sented with high tumor burden,” said James Caruso, pres­i­dent and chief exec­u­tive officer of Cellectar Biosciences. “Most drugs cur­rently approved for third-line or later R/R MM average approx­i­mately 12 months of sur­vival, in­­clud­ing sev­er­al recent ap­prov­als. We be­lieve extending OS to beyond 19 months with a more patient-friendly dosing regi­men provides both a unique prod­uct profile and poten­tial for beneficial patient out­comes.”

The objective of this multi­center, open-label, Phase 1b dose-escalation study is the char­ac­ter­i­za­tion of safety and tol­er­a­bil­ity of CLR 131 admin­istered as a single-dose, 30-minute in­fusion in patients with R/R MM. Patients re­ceived doses of 12.5 mCi/m2 up to 31.25 mCi/m2. All doses were deemed safe and well tol­er­ated by an in­de­pen­dent data monitoring com­mit­tee.

Data from a fifth cohort, re­leased in August, eval­u­ated a split or frac­tion­ated dose of 31.25 mCi/m2 for tol­er­a­bil­ity and safety. The dosing schedule provided higher average drug exposure but lower peak serum levels than non-fractionated dosing poten­tially reducing adverse events and im­prov­ing ef­fi­cacy. The in­de­pen­dent Data Monitoring Com­mit­tee (DMC) de­ter­mined the frac­tion­ated dose used in Cohort 5 to be safe and well tol­er­ated and rec­om­mended ad­vancement to a higher dose cohort.

About Phospholipid Drug Conjugates™

Cellectar's prod­uct can­di­dates are built upon a pat­ented de­livery and retention plat­form that uti­lizes op­ti­mized phos­pholipid ether-drug con­ju­gates (PDCs™) to target cancer cells. The PDC plat­form sel­ectively de­livers diverse onco­logic pay­loads to can­cer­ous cells and cancer stem cells, in­­clud­ing hema­to­logic cancers and solid tumors. This sel­ective de­livery allows the pay­loads’ thera­peutic window to be modified, which may main­tain or en­hance drug potency while reducing the num­ber and severity of adverse events. This plat­form takes ad­van­tage of a metabolic path­way uti­lized by all tumor cell types in all cell cycle stages. Compared with other targeted de­livery plat­forms, the PDC plat­form’s mech­a­nism of entry does not rely upon spe­cif­ic cell surface epitopes or an­ti­gens. In addi­tion, PDCs can be con­ju­gated to mol­e­cules in nu­mer­ous ways, thereby in­creas­ing the types of mol­e­cules sel­ectively de­liv­ered. Cellectar be­lieves the PDC plat­form holds poten­tial for the discovery and devel­op­ment of the next gen­er­a­tion of cancer-targeting agents.

About CLR 131

CLR 131 is Cellectar’s inves­ti­ga­tional radioiodinated PDC ther­apy that exploits the tumor-targeting properties of the com­pany's pro­pri­e­tary phos­pholipid ether (PLE) and PLE analogs to sel­ectively de­liver radi­a­tion to malignant tumor cells, thus minimizing radi­a­tion exposure to nor­mal tissues. CLR 131 is in a Phase 2 clin­i­cal study in R/R MM and a range of B-cell malig­nan­cies and a Phase 1b clin­i­cal study in patients with R/R MM exploring frac­tion­ated dosing. The objective of the multi­center, open-label, Phase 1b dose-escalation study is the char­ac­ter­i­za­tion of safety and tol­er­a­bil­ity of CLR 131 in patients with R/R MM. Patients in Cohorts 1-4 re­ceived single doses of CLR 131 ranging from 12.5 mCi/m2 to 31.25 mCi/m2. All study doses have been deemed safe and well tol­er­ated by an in­de­pen­dent Data Monitoring Com­mit­tee. The com­pany is cur­rently initiating a Phase 1 study with CLR 131 in pedi­atric solid tumors and lym­phoma, and is planning a sec­ond Phase 1 study in com­bi­na­tion with ex­ternal beam radi­a­tion for head and neck cancer.

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 our PDC plat­form to de­vel­op thera­peutics that spe­cif­i­cally target treat­ment to cancer cells. Through R&D col­lab­o­rations, the com­pany’s strat­e­gy is to gen­er­ate near-term capital, supple­ment in­ternal resources, gain access to novel mol­e­cules or pay­loads, ac­cel­er­ate prod­uct can­di­date devel­op­ment and broaden our pro­pri­e­tary and part­nered prod­uct pipe­lines.

The com­pany's lead PDC thera­peutic, CLR 131, is in a Phase 1 clin­i­cal study in patients with R/R MM and a Phase 2 clin­i­cal study in R/R MM and a range of B-cell malig­nan­cies. The com­pany is cur­rently initiating a Phase 1 study with CLR 131 in pedi­atric solid tumors and lym­phoma, and is planning a sec­ond Phase 1 study in com­bi­na­tion with ex­ternal beam radi­a­tion for head and neck cancer. The com­pany’s prod­uct pipe­line also in­cludes two pre­clin­i­cal PDC chemo­thera­peutic pro­grams (CLR 1700 and 1900) and part­nered assets in­clude PDCs from mul­ti­ple R&D col­lab­o­rations.

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, 2017 and our Form 10-Q for the quar­ter­ly period ended June 30, 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.