MAJESTEC-4 Trial

SOCIETY or ASH Annual Meeting & Exposition 494 Phase 3 Study of Teclistamab (Tec) in Combination with Lenalidomide (Len) and Tec Alone Versus Len Alone in Newly Diagnosed Multiple Myeloma (NDMM) As Maintenance Therapy Following Autologous Stem Cell Transplantation (ASCT): Safety Run-in (SRI) Results from the Majestec-4/EMN30 Trial Program: Oral and Poster Abstracts Type: Oral Session: 654. Multiple Myeloma: Pharmacologic Therapies: Targeting BCMA Hematology Disease Topics & Pathways: Research, Clinical trials, Bispecific Antibody Therapy, Clinical Research, Plasma Cell Disorders, Diseases, Treatment Considerations, Biological therapies, Lymphoid Malignancies, Adverse Events Sunday, December 8, 2024: 9:45 AM Elena Zamagni, MD¹*, Tobias Silzle, MD²*, Ivan Å piA ka³*, Sabrin Tahri, MD⁴*, Sarah Lonergan⁴, Inger S. Nijhof, MD, PhD⁵*, Antonietta Pia Falcone, MD, PhD⁶*, Evangelos Terpos7*, Jakub Radocha, MD, PhD⁸*, Roberto Mina9*, Guldane Cengiz Seval, MD¹⁰*, Meral Beksac, MD¹¹, Cesar Rodriguez, MD¹²*, Marcelo C. Pasquini, MD, MS¹³,¹⁴, Michel Delforge¹⁵*, Vania Hungria, MD, PhD¹⁶, Donna Reece, MD¹⁷, Philippe Moreau, MD, PhD¹⁸*, Yael C. Cohen¹⁹, Kihyun Kim, MD²⁰*, Dominik Dytfeld2¹*, JiA™ MinaÅ Irene Strass/2³*, Jelena Bila, MD²⁴*, Martin Schreder, MD²⁵*, Janusz Krawczyk, MD²⁶, Fredrik Schjesvold, MD, PhD²⁷, Caroline Cicin-Sain²⁸*, Christoph Driessen²⁹, Gordon Cook³⁰*, Lugui Qiu, MD³¹, Gonzalo Martin Garate, MD³²*, Agoston Gyula Szabo, MD, PhD³³, Roman HÄ¡jek³⁴, Marc S. Raab, M.D.³⁵*, Silvia Mangiacavalli, MD³⁶*, Hermann Einsele, MD³⁷, Andrew Spencer, MBBS³⁸*, Mario Boccadoro, MD³⁹,⁴⁰, Helen Vassalou41*, Lixia Pei42*, Yingqi Shi43*, Maria Krevvata, PhD44*, Ryan Gruber44*, Caline Sakabedoyan⁴⁵*, Margaret Cobb⁴⁶*, Jagoda Jasielec⁴³*, Himal Amin⁴³*, Rachel Kobos, MD⁴³, Pieter Sonneveld, MD⁴⁷ and Niels W.C.J. van de Donk, MD, PhD48*

EMN30/MajesTEC-4 SRI: Hematologic TEAEs Cohort 1: Cohort 2: Tec QW Q4W + Len Cohort 3: Median relative dose intensityᵇ: Tec Q4W + Len Tec Q4W (n=32) (n=32) (n=30) - Tec: 96-99%c; Len: 55-56% Median follow-up, mo 32.7 21.2 Discontinuation due to TEAEsd 21.2 TEAEs,ª n (%) Any Grade Any Grade Any Grade - Cohort 1: 4 (12.5%) grade 3/4 grade 3/4 grade 3/4 Any TEAE 32 (100) 32 (100) - Cohort 2: 4 (12.5%) 32 (100) 31 (96.9) 30 (100) 20 (66.7) Hematologic TEAEs - Cohort 3: 1 (3.3%) Neutropenia 30 (93.8) 30 (93.8) 25 (78.1) 25 (78.1) 22 (73.3) Two Grade 5 TEAEs 19 (63.3) Leukopenia 8 (25.0) 3 (9.4) 0 0 2 (6.7) 1 (3.3) - COVID-19 (Cohort 2) Lymphopenia 2 (6.3) 1 (3.1) 4 (12.5) 4 (12.5) 6 (20.0) 4 (13.3) - Radiculopathy (Cohort 2) Thrombocytopenia 6 (18.8) 2 (6.3) 1 (3.1) 1 (3.1) 2 (6.7) 0 Anemia Two non-TEAE deaths 3 (9.4) 0 2 (6.3) 1 (3.1) 3 (10.0) 0 Febrile neutropenia 3 (9.4) 3 (9.4) 3 (9.4) 3 (9.4) 0 - Complications after allo-SCT (Cohort 1)e 0 Eosinophilia 1 (3.1) 1 (3.1) 1 (3.1) 1 (3.1) 0 0 - Progressive disease (Cohort 3) High median RDI maintained with Tec and low rates of discontinuation due to TEAEs allo-SCT, AEs (graded allogenic per NCI-CTCAE stem cell transplant; Version 5.0); MDS, any myelodysplastic grade in >25% syndrome; of patients NCI-CTCAE, or grade 3/4 in National >1 patient. Cancer Ratio Institute of total Common dose actually Terminology received/total Criteria for Adverse Events: RDI, relative dose intensity; TEAE, treatment-emergent adverse event. are excluded. Includes SUD as well as repeat SUD if Presented applicable. Discontinuation NWCJ of all study treatment. Patient developed MDS and had a fatal planned event due dose to per severe protocol. immunosuppression Planned doses not after received allo-SCT due unrelated to study to drug study discontinuation treatment. by van de Donk at the 31st European Hematology Association (EHA) Annual Meeting; June 11-14, 2026; Stockholm, Sweden 7

EMN30/MajesTEC-4 SRI: Cumulative Incidence of Grade 3/4 Infections 1.0 0.9 0.8 0.7 Cumulative incidence of 0.6 Tec Q4W + Len Q4W + Len grade 3/4 infections Tec QW 0.5 0.4 0.3 0.2 0.1 Tec Q4W 0 0 3 6 9 12 15 18 21 24 27 30 33 36 Study month Number at risk 6 5 4 0 32 28 25 25 23 19 14 14 Tec QW > Q4W + Len Tec Q4W + Len 32 27 24 17 14 12 2 0 0 0 0 27 Tec Q4W 30 24 22 22 22 22 21 1 0 0 0 0 Cumulative incidence of grade 3/4 infections plateaued with Tec Q4W from ~6 months 10 Presented by NWCJ van de Donk at the 31st European Hematology Association (EHA) Annual Meeting; June 11-14, 2026; Stockholm, Sweden || EMN30/MajesTEC-4 SRI: Response Rates Post-ASCT and During Maintenance Efficacy data cutoff: December 8, 2025 60.0% 96.7% 100% 40.6% 96.9% >CR rate 46.9% 10.0 sCR 100 12.5 CR 31.3 80 VGPR 28.1 50.0 75.0 76.7 PR 60 15.6 Patients (%) 93.8 40 43.8 34.4 23.3 20 21.9 20.0 18.8 15.6 3.1 16.7 3.3 6.3 0 Response Best response Response Best response Response Best response post-ASCT on maintenance post-ASCT on maintenance post-ASCT on maintenance Tec QW > Q4W + Len (n=32) Tec Q4W + Len (n=32) Tec Q4W (n=30) Median follow-up, 35.3 mo Median follow-up, 23.7 mo Median follow-up, 23.7 mo >CR was reached in nearly 100% of patients during maintenance across cohorts sCR, stringent complete response; VGPR, very good partial response. Response based on investigator assessment *Post-ASCT consolidation. 11 Presented by NWCJ van de Donk at the 31st European Hematology Association (EHA) Annual Meeting: June 11-14, 2026; Stockholm, Sweden || EMN30/MajesTEC-4 SRI: Progression-Free Survival Estimated 18-mo Estimated 24-mo 96.4% 96.6% 100 Cohort 3: Median PFS was not 90 Cohort 2: Tec Q4W 93.8% Cohort 1: Tec Q4W +Len Tec QW > Q4W + reached in any cohort 80 Len % of patients progression 70 Only 3 patients progressed free and alive 60 - 2 in Cohort 1 50 40 - 1 in Cohort 3 30 20 10 0 0 3 6 9 12 15 18 21 24 27 30 33 Number at risk PFS (months) Tec QW + Q4W + Len 32 32 32 32 31 29 28 28 28 25 2 0 31 31 31 31 26 5 0 0 0 0 0 Tec Q4W + Len 32 Tec Q4W 30 29 28 27 26 26 6 0 0 0 0 0 Estimated 18- and 24-month PFS rates were 94%-97%, with only 3 progression events Clinical cutoff date: May 7, 2025. 13 Presented by NWCJ van de Donk at the 31st European Hematology Association (EHA) Annual Meeting; June 11-14, 2026; Stockholm, Sweden || EMN30/Majes TEC-4 SRI: Tec ± Len as Maintenance Therapy Post-ASCT in NDMM Tec and Tec-Len were safety administered as 2-year fixed-duration post-ASCT maintenance, with convenient Tec Q4W dosing after cycle 1 (median follow-up ~2-3 years) CRS and infections were manageable via established protocols, supporting use across practice settings Tec-based maintenance delivered remarkable depth of response post-ASCT, which deepened over time: - -97%-100% of patients achieved >CR post-ASCT - 90%-100% of evaluable patients achieved MRD-negative CR at 12 months Estimated 18- and 24-mo PFS rates were 94%-97%, with only 3 progression events The randomized portion is open and evaluating Tec-Len, Tec, and Len as maintenance with monthly Tec dosing Tec + Len as post-ASCT maintenance in NDMM is a promising new maintenance approach Presented by NWCJ van de Donk at the 31st European Hematology Association (EHA) Annual Meeting: June 11-14, 2026; Stockholm, Sweden 14

EMN30/MajesTEC-4: Study Design SRI Phase 3, randomized study Key eligibility criteria: SRI Cohort 1 Tec-Lenb Dual primary end points: NDMM Tec QW Q4W PFS Tec Q4W 12-month MRD-negative CR (by NGF; 10⁻⁵) + ECOG PS score of 0-2 Len Key secondary end point: Received 4-6 cycles of SRI Cohort 2 3- or 4-drug induction therapy Tec Q4W antibody) and N=1500 ASCT + consolidation + Len with >PR 1:1:1 randomization OS (PI and/or IMiD ± anti-CD38 Tec Select secondary end points: >CR Tec Q4W CR conversion MRD-negative CR SRI Cohort 3 MRD-negative conversion Sustained MRD-negative CR PFS2 Tec Q4W Lenb TTNT Safety CR, complete response; ECOG PS, Eastern Cooperative Oncology Group performance status; MRD, minimal residual disease; NGF, next-generation flow cytometry; OS, overall survival; PFS, progression-free survival; PFS2, progression-free survival after next line of therapy; PI, proteosome inhibitor; PR, partial response; QW, weekly; Q4W, every 4 weeks; TTNT. time to next treatment. "Single or tandem ASCT permitted. Len dose: 10 mg once daily; may increase to 15 mg once daily on Day 1 of Cycle 4 (Len) or Cycle 5 (Tec-Len) if 10 mg was tolerated 3 Presented by NWC van de Donk at the 31st European Hematology Association (FHA) Annual Meeting: June 11-14 2026 Stockholm Sweden || EMN30/MajesTEC-4 SRI: Dosing 28-day cycles Cycle 1 Cycle 2 Cycles 3-6 Cycles 7-26c Tec SUDᵃ + Tec QW Q4W Tec 1.5 mg/kg QW Tec 3.0 mg/kg Q2W Tec 3.0 mg/kg Q4Wb Tec 1.5 mg/kg on D8, D15, + Len + Len + Len + Len and D22 Tec Q4W Tec SUDᵃ + Tec 3.0 mg/kg Q4Wb + Len Tec 1.5 mg/kg on D8 and D15 + Len Tec SUDᵃ + Tec Q4W Tec 3.0 mg/kg Q4W Tec 1.5 mg/kg on D8 and D15 Len was initiated at 10 mg/day from Cycles 2 to 4, followed by 15 mg/day in Cycles 5 to 26, if tolerated All cohorts are 2-year fixed-duration maintenance regimens D, Day; Q2W, every 2 weeks; SUD, step-up dosing. "Patients received SUD of 0.06 and 0.3 mg/kg on D1 and D3, respectively. Patients who achieved >CR on Tec-Len after Cycle 13 discontinued Tec. Patients on Tec-Len could continue Len after Cycle 26. 4 Presented by NWCJ van de Donk at the 31st European Hematology Association (EHA) Annual Meeting: June 11-14, 2026; Stockholm, Sweden || EMN30/MajesTEC-4 SRI: Demographic and Disease Characteristics Tec QW + Q4W + Len Tec Q4W + Len Tec Q4W Characteristic (n=32) (n=32) (n=30) Median(range) age, y 58.5 (31-73) 58.0 (38-73) 58.5 (34-72) 265, n (%) 12 (37.5) 5 (15.6) 9 (30.0) Male, n n (%) 21 (65.6) 21 (65.6) 22 (73.3) White, race, n (%) 32 (100) 32 (100) 30 (100) ISS disease stage at diagnosis, n/N (%) I 18/32 (56.3) 7/32 (21.9) 9/28 (32.1) II 7/32 (21.9) 10/32 (31.3) 11/28 (39.3) III 7/32 (21.9) 15/32 (46.9) 8/28 (28.6) High cytogenetic risk at diagnosis,* n/N (%) 7/25 (28.0) 5/29 (17.2) 6/25 (24.0) Induction regimen for MM, n (%) PP IMID 28 (87.5) 28 (87.5) 30 (100) PP . IMID . anti-CD384 11 (34.4) 19 (59.4) 20 (66.7) Prior consolidation, n (%) 6(18.8) 12 (37.5) 10 (33.3) Median (range) time from ASCT to maintenance, mo 4.3 (2.0-6.2) 5.1 (1.8-7.4) 4.5 (2.1-6.9) iss, International Staging System High cytogenetic - presence of at of del(17p). (4.14) or (14,16) 9394 received borlezomb and 5/94 (3.2%) received carliformb. 5394 (56.4%) received Len, 36/94 5%) received haldomide, and 1/94 (%) received pomaldomide 5094 (53.2%) received and 154 "%)received saturnab. Presented by NWCJ - Donk - The 21st European Hematology Association (EHA) Annual Meeting June 11-54, 2020 Stockholm Seeden

EMN30/MajesTEC-4 SRI: Hematologic TEAEs Cohort 1: Cohort 2: Cohort 3: Median relative dose intensityᵇ: Tec QW Q4W + Len Tec Q4W + Len Tec Q4W - Tec: 96-99%c; Len: 55-56% (n=32) (n=32) (n=30) Discontinuation due to TEAEsd Median follow-up, mo 32.7 21.2 21.2 Any Grade Any Grade Any Grade - Cohort 1: 4 (12.5%) TEAEs,ᵃ n (%) grade 3/4 grade 3/4 grade 3/4 - Cohort 2: 4 (12.5%) Any TEAE 32 (100) 32 (100) 32 (100) 31 (96.9) 30 (100) 20 (66.7) - Cohort 3: 1 (3.3%) Hematologic TEAEs Two Grade 5 TEAEs Neutropenia 30 (93.8) 30 (93.8) 25 (78.1) 25 (78.1) 22 (73.3) 19 (63.3) Leukopenia 8 (25.0) 3 (9.4) 0 0 2 (6.7) 1 (3.3) - COVID-19 (Cohort 2) Lymphopenia 2 (6.3) 1 (3.1) 4 (12.5) 4 (12.5) 6 (20.0) 4 (13.3) - Radiculopathy (Cohort 2) Thrombocytopenia 6 (18.8) 2 (6.3) 1 (3.1) 1 (3.1) 2 (6.7) 0 Two non-TEAE deaths Anemia 3 (9.4) 0 2 (6.3) 1 (3.1) 3 (10.0) 0 - Complications after allo-SCT (Cohort 1)e Febrile neutropenia 3 (9.4) 3 (9.4) 3 (9.4) 3 (9.4) 0 0 - Progressive disease (Cohort 3) Eosinophilia 1 (3.1) 1 (3.1) 1 (3.1) 1 (3.1) 0 0 High median RDI maintained with Tec and low rates of discontinuation due to TEAEs allo-SCT, allogenic stem cell transplant; MDS, myelodysplastic syndrome; NCI-CTCAE, National Cancer Institute Common Terminology Criteria for Adverse Events; RDI, relative dose intensity; TEAE, treatment-emergent adverse event. "AEs (graded per NCI-CTCAE Version 5.0): any grade in >25% of patients or grade 3/4 in >1 patient. Ratio of total dose actually received/total planned dose per protocol. Planned doses not received due to study drug discontinuation are excluded Includes SUD as well as repeat SUD if applicable. Discontinuation of all study treatment "Patient developed MDS and had a fatal event due to severe immunosuppression after allo-SCT unrelated to study treatment 7 Presented by NWCJ van de Donk at the 31st European Hematology Association (EHA) Annual Meeting; June 11-14, 2026; Stockholm, Sweden || EMN30/MajesTEC-4 SRI: Nonhematologic TEAEs Tec QW Q4W + Len Tec Q4W + Len Tec Q4W All CRS was grade 1/2 (38.3%/6.4%) (n=32) (n=32) (n=30) - Most occurred after SUD 1/SUD 2 Median follow-up, mo 32.7 21.2 21.2 (37.2%/8.5%) TEAEs,ᵃ n (%) Any grade Grade 3/4 Any grade Grade 3/4 Any grade Grade 3/4 - All resolved and no Nonhematologic TEAEsᵇ discontinuations URTI 22 (68.8) 1 (3.1) 13 (40.6) 0 12 (40.0) 0 - 11.7% received tocilizumab for Diarrhea 17 (53.1) 3 (9.4) 12 (37.5) 1 (3.1) 8 (26.7) 0 CRS treatment CRS 16 (50.0) 0 13 (40.6) 0 13 (43.3) 0 No ICANS Cough 14 (43.8) 0 8 (25.0) 0 10 (33.3) 0 COVID-19 13 (40.6) 1 (3.1) 7 (21.9) 0 9 (30.0) 1 (3.3) Injection-site erythema 7 (21.9) 0 12 (37.5) 0 9 (30.0) 0 Fatigue 10 (31.3) 1 (3.1) 9 (28.1) 1 (3.1) 6 (20.0) 0 PSN 5 (15.6) 0 9 (28.1) 0 2 (6.7) 0 Pneumonia 8 (25.0) 4 (12.5) 3 (9.4) 0 2 (6.7) 1 (3.3) CRS was mostly grade 1 and occurred during SUD, with no Tec discontinuations CRS, cytokine release syndrome; ICANS, immune effector cell-associated neurotoxicity syndrome; PSN, peripheral sensory neuropathy; URTI, upper respiratory tract infection. "AEs (graded per NCI-CTCAE Version 5.0); any grade in >25% of patients or grade 3/4 in -10% of patients. Hypogammaglobulinemia based on TEAE reporting also met the >25% threshold and is reported separately. 8 Presented by NWCJ van de Donk at the 31st European Hematology Association (EHA) Annual Meeting: June 11-14, 2026; Stockholm, Sweden || EMN30/MajesTEC-4 SRI: Response Rates Post-ASCT and During Maintenance Efficacy data cutoff: December 8, 2025 ≥CR rate 46.9% 100% 40.6% 96.9% 60.0% 96.7% 100 12.5 10.0 sCR 31.3 80 CR 28.1 VGPR 75.0 50.0 60 15.6 76.7 Patients (%) PR 93.8 40 34.4 43.8 23.3 20 21.9 20.0 18.8 15.6 3.1 16.7 3.3 0 6.3 Response Best response Response Best response Response Best response post-ASCT on maintenance post-ASCT on maintenance post-ASCT on maintenance Tec QW Q4W + Len (n=32) Tec Q4W + Len (n=32) Tec Q4W (n=30) Median follow-up, 35.3 mo Median follow-up, 23.7 mo Median follow-up, 23.7 mo ≥CR was reached in nearly 100% of patients during maintenance across cohorts sCR, stringent complete response; VGPR, very good partial response. Response based on investigator assessment "Post-ASCT * consolidation 11 Presented by NWCJ van de Donk at the 31st European Hematology Association (EHA) Annual Meeting: June 11-14, 2026; Stockholm, Sweden || EMN30/MajesTEC-4 SRI: Progression-Free Survival Estimated 18-mo Estimated 24-mo 96.4% 100 96.6% 90 Cohort 3: Tec Q4W Cohort 2: 80 93.8% Tec Q4W +Len Cohort 1: Median PFS was not Tec QW -> Q4W + % of patients progression 70 reached in any cohort Len free and alive 60 Only 3 patients progressed 50 - 2 in Cohort 1 40 30 - 1 in Cohort 3 20 10 0 0 3 6 9 12 15 18 21 24 27 30 33 Number at risk PFS (months) Tec QW -> Q4W + Len 32 32 32 32 31 29 28 28 28 25 2 0 Tec Q4W + Len 32 31 31 31 31 26 5 0 0 0 0 0 Tec Q4W 30 29 28 27 26 26 6 0 0 0 0 0 Estimated 18- and 24-month PFS rates were 94%-97%, with only 3 progression events Clinical cutoff date: May 7. 2025. 13 Presented by NWCJ van de Donk at the 31st European Hematology Association (EHA) Annual Meeting: June 11-14, 2026; Stockholm, Sweden