Cellectar Biosciences (CLRB) investor relations material

Strategic priorities and pipeline

• Phase 3 confirmatory study of iopofosine | 131 in Waldenström macroglobulinemia (WM) is ongoing; first patient enrollment projected for 1Q27, with a U.S. accelerated approval application planned for 1H27 using Phase 2b data and ongoing Phase 3 validation.

• Phase 3 IRIS WaM plans 200 patients randomized 1:1 against rituximab, cyclophosphamide and dexamethasone; PFS is the primary endpoint for full approval, with MRR and safety as secondary endpoints.

• CLR 125 Phase 1b TNBC study initiated, with enrollment ongoing; CLR 225 is Phase 1 ready for pancreatic cancer, with trial initiation TBD.

• Strategic priorities include U.S. and EU development and commercialization approaches for iopofosine, additional platform collaborations, and advancement of solid-tumor studies.

PDC platform

• Phospholipid drug conjugates target lipid rafts, described as prevalent across tumor cells and types; the presentation reports ~10-day stability in tumor cells versus milliseconds in healthy tissue.

• Platform design supports diverse payloads, pan-cancer targeting, rapid uptake, cytoplasmic entry and CNS penetration; the presentation describes intracellular delivery through lipid raft transmembrane flipping.

• Disrupting lipid rafts with MBCD reduced fluorescent-tagged PDC uptake by ~60% in A549 cells, supporting the proposed lipid-raft uptake mechanism.

• Platform strategy spans radioisotopes and other payloads; the presentation cites a broad IP portfolio covering radio-conjugates, small molecules, oligonucleotide payloads and linker technology.

WM pivotal trial results

• Phase 2b CLOVER-WaM enrolled a heavily pretreated population: median 4 prior therapy lines; 73.8% had prior BTKi treatment and 66.2% were dual refractory to BTKi and rituximab.

• At the Dec. 2025 data cut, evaluable patients (n=55) had ORR 83.6%, MRR 61.8%, DCR 98.2% and VGPR/CR rate 14.5%; all patients had at least 12 months of follow-up.

• At the Dec. 2025 data cut, median duration of response was 533 days (17.8 months) among mITT responders; median PFS was 406 days (13.5 months) in the mITT population.

• Common hematologic toxicities included thrombocytopenia (86.2%), neutropenia (80.0%) and anemia (64.6%); reported cytopenias were manageable, and all patients recovered.

• U.S. and EU WM market estimates were 26,000 and ~36,000 prevalent patients, respectively; the presentation describes concentrated specialist care and limited approved treatment options.