Cellectar Biosciences, Inc. · NASDAQ:CLRB

Cellectar Biosciences — Technical Presentation (March 2020)

14 slides from Cellectar Biosciences's technical presentation, Mar 9, 2020

1. Slide 1: Fractionated Dosing of CLR 131 in Patients with Relapsed or Refractory Multiple Myeloma (RRMM)

   FRACTIONATED DOSING OF CLR 131 IN PATIENTS WITH RELAPSED OR REFRACTORY MULTIPLE MYELOMA (RRMM) AILAWADHI S1, STIFF P2, IBRAHIM E3, VALLURUPALLI A4, CULL E5, GREEN DJ6, OLIVER K7, LONGCOR J7 1MAYO CLINIC FLORIDA; 2LOYOLA UNIVERSITY CARDINAL BERNARDIN CANCER CENTER; 3REDLANDS COMMUNITY HOSPITAL; 4UNIV

2. Slide 2: Background

   Background A B E A, B, C, D, E demonstrates presence of lipid rafts on • Phospholipid ether (PLE) molecules are various tumors . A=prostate; B=pancreatic; C=renal; utilized to deliver cytotoxic molecules to D=lung; E is co-culture of lung tumors C D tumor and normal fibroblasts and treated or 24 hou

3. Slide 3: Rationale in RR Multiple Myeloma

   Rationale in RR Multiple Myeloma • CLR 131 is a targeted radiotherapeutic leveraging PLE molecules to provide targeting of an I-131 payload • CLR 131 has been administered to over 80 patients (Phase 1/Phase 2 studies, hematologic and solid tumors) Selective uptake of radioiodinated CLR 124 in MM fla

4. Slide 4: Dosing Regimen Rationale

   Dosing Regimen Rationale Analysis of Bexxar and DeNardo Data • It was demonstrated that 75cGy should be the target absorbed dose to be efficacious with I-131 (Bexxar)1 • Patients with rapid clearance will require higher doses to achieve the appropriate area under the curve to create the absorbed dos

5. Slide 5: CLR 131 RR Hematologic Studies Overview

   CLR 131 RR Hematologic Studies Overview (Phase 1: NCT02278315; CLOVER-1: NCT02952508) Phase 1 RRMM Phase 2 RR B-cell Malignancies Denotes Ongoing Follow-up (≥ 1yr After Last Dose) 15 mCi/m2 x 2 20 mCi/m2 x 2 Up to 10 patients with a CBR of ≥20% in each cohort Data presented focuses on relapsed or re

6. Slide 6: RRMM Fractionated Dose Patient Characteristics

   RRMM Fractionated Dose Patient Characteristics All Bolus dose Fractionated Dose Fractionated Dose Fractionated Fractionated Cohorts Together: 31.25mCi/m2 n=3 31.25mCi/m2 n=10 37.5mCi/m2 n=6 MM Subjects n=16 • Median age: 71 years Median Age Min 67 59 69 51 74 59 71 51 • Average bone marrow plasma ce

7. Slide 7: Safety Population - Summary of TEAEs

   Safety Population - Summary of TEAEs (Treatment Emergent AE / Regardless of Causality) >20% All Grades Grade 3/4 Only Fractionated Fractionated All Fractionated Fractionated All Bolus Dose Dose Dose Fractionated Bolus Dose Dose Dose Fractionated 31.25mCi/m2 31.25mCi/m2 37.5mCi/m2 Subjects 31.25mCi/m

8. Slide 8: CLR 131 Safety Population - Cytopenia Trends

   CLR 131 Safety Population - Cytopenia Trends 250 Average Platelet Count 200 150 Average 31.25 Bolus 100 Average 31.25 Fractionated Average 37.5 Fractionated 50 0 Screening Day 1 Day 8 Day 15 Day 22 Day 29 Day 36 Day 43 Day 50 Day 57 Day 64 Day 71 Day 78 Day 85 16.0 15.0 Average Hemoglobin 14.0 13.0

9. Slide 9: Tumor Assessment & Disease Control Rates

   Tumor Assessment & Disease Control Rates (During 85 Day Study Assess. Period) 3.5 100% Disease Control Tumor Response (n=16) 3 Fractionated Fractionated All Bolus Dose Dose Dose Fractionated 2.5 31.25mCi/m2 31.25mCi/m2 37.5mCi/m2 MM Subjects n=3 (%) n=7 (%) n=6 (%) n=13 (%) 2 Partial 1 (33) 1 (14.3)

10. Slide 10: Waterfall Plot of Best Patient Responses

    Waterfall Plot of Best Patient Responses Patients 31.25mCi/m2 Bolus 40 Stable Disease 31.25mCi/m2 Fractionated 20 37.5mCi/m2 Fractionated 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 -20 Minimal Response -40 Partial Response -60 -80 -100 Fractionated dosing results in greater reduction in M-protein or F

11. Slide 11: Kaplan Meier Curve of Progression Free Survival

    Kaplan Meier Curve of Progression Free Survival • All 3 dosing regimens show CLR 131 Progression Free Survival 31.25mCi/m2 bolus 120 31.25mCi/m2 fractionated progression free survival (PFS) is 37. 5mCi/m2 fractionated consistent with other RRMM drugs 100 − To date, median PFS approximately 3-4 month

12. Slide 12: Pharmacokinetics By Dosing Regime of CLR 131

    Pharmacokinetics By Dosing Regime of CLR 131 25mCi/m2 31.25mCi/m2 37.5mCi/m2 fractionated 30mCi/m2 fractionated x 2 • Increased plasma exposure has demonstrated increased tumor uptake and increased responses • Cycle two could more than double the plasma exposure further increasing tumor uptake and p

13. Slide 13: Conclusions

    Conclusions • CLR 131 is well tolerated with cytopenic events being the majority of TEAE reported – Fractionated dosing improves tolerability over bolus dosing • CLR 131 demonstrates efficacy in late line, heavily pretreated and multiple-agent refractory multiple myeloma patients – Approximately 30%

14. Slide 14: Acknowledgements

    Acknowledgements Mayo Clinic Florida1,2 Redlands Community Hospital2 University of Wisconsin Carbone Cancer University of Rochester2 Center1,2 Cardinal Bernardin Cancer Center, Loyola Prism Health Cancer Center2 University1,2 Fred Hutchinson Cancer Research Center2 Ochsner Cancer Institute2 Universi

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