BL-B01D1 (iza-bren) Development Program Trial

[Slide 1] Promising Efficacy Seen in Treatment-naïve Patients Total BOR, n (%) (N = 77) Iza-bren 2.5 mg/kg D1D8Q3W Iza-bren D1D8 Q3W+Serplulimab 4.5 mg/kg Q3W PR (N = 40) Iza-bren 2.75 mg/kg D1D8Q3W (N = 37) Confirmed PR 68 (88.3) 34 (85.0) PR pending confirmation¹¹ 60 (77.9) 34 (91.9) 31 (77.5) SD 1 (1.3) 29 (78.4) 0 PD 5 (6.5) 1 (2.7) 3 (7.5) 4 (5.2) 2 (5.4) ORR, % (95% CI) 3 (7.5) 88.3 (79.0, 94.5) 1 (2.7) cORR, % (95% CI) 85.0 (70.2, 94.3) 77.9 (67.0, 86.6) 91.9 (78.1, 98.3) DCR, % (95% CI) 77.5 (61.5,89.2) 94.8 (87.2, 98.6) 78.4 (61.8, 90.2) mDOR, mo (95% CI) 92.5 (79.6, 98.4) 97.3 (85.8,99.9) 7.3 (5.6, 8.3) mPFS, mo (95% CI) 7.3 (5.3,8.3) 8.0 (5.5,8.6) 8.2 (6.7, 9.6) 8.2 (4.4,9.6) Median FU for PFS, mo (95% CI) 8.3 (6.9,9.7) 10.8 (8.3, 12.3) 9.8 (8.1, 12.4) 10.8 (8.3, 12.5) 12-mo OS rate, % (95% CI) 80.8 (66.1, 89.6) 85.7 (68.7, 93.9) 76.5 (51.4, 89.8) Median FU for OS, mo (95% CI) 10.5 (9.7, 11.3) 10.5 (9.7, 11.6) 10.4 (9.2,11.7) Patients with at least one post baseline scan were included in the analysis. [1] Patients still on study with tumor assessment of PR who have not yet reached to the next time point of tumor assessment Cl: confidence interval; cORR: confirmed objective response rate; PR: partial response; SD: stable disease; PD: progressive disease; FU: follow-up time. Data cutoff: November 30th, 2025 Fei Zhou, MD, PhD Organisers Partners Content of this presentation is copyright and responsibility of the author. Permission is required for re-use. ESMO IASLC INTERNATIONAL g FOR STUDY ESTRO 2 ETOP-IBCSG of Lund CANCER PARTNERS FOUNDATION --- [Slide 2] Study Design Presented Key Eligibility Criteria Stage I Stage II ES-SCLC confirmed by Pts who failed standard treatment Treatment-naive pts histopathology and/or cytology Failed standard treatment (Stage I) or treatment-naive (Stage II) Iza-bren 2.75 mg/kg D1D8Q3W Iza-bren 2.5 mg/kg D1D8Q3W ECOG performance status of 0-1 + Serplulimab* 4.5 mg/kg Q3W + Serplulimab 4.5 mg/kg Q3W At least one measurable lesion per RECIST v1.1 Iza-bren 2.75 mg/kg D1D8Q3W Adequate organ and marrow function + Serplulimab 4.5 mg/kg Q3W Primary: ORR, RP2D (for combination treatment) Secondary: PFS, DCR, DOR, OS, PK, immunogenicity, DDI, safety Safety and efficacy results for stage II are presented. ECOG: Eastern Cooperative Oncology Group; ORR: objective response rate; RP2D: recommended phase 2 dose; PFS: progression-free survival; DCR: disease control rate; DOR: duration of response; OS: overall survival; PK: pharmacokinetics; DDI: drug-drug interaction : PD-1 inhibitor, which has been approved in China as first-line treatment for ES-SCLC in combined with carboplatin/etoposide. Fei Zhou, MD, PhD Organisers Content of this presentation is copyright and responsibility of the author. Permission is required for re-use Partners ESMD IASLC INTERNATIONAL FOR STUDY OF LONG CANCER ESTRO L ETOP-IBCSG PARTNERS FOUNDATION --- [Slide 3] Conclusions Iza-bren ES-SCLC. combined with serplulimab as a first-line treatment showed a tolerable and manageable safety profile in patients with Hematologic support. toxicities were the most common AEs, but were effectively managed by supportive care and growth factor Rate of iza-bren treatment discontinuation due to TRAEs was low overall (7.3%), with rates of 2.4% in the iza-bren 2.5 mg/kg D1D8Q3W cohort and 12.2% in the 2.75 mg/kg D1D8Q3W cohort. Encouraging antitumor activity was observed with iza-bren combined with serplulimab in 1L ES-SCLC: In the cohort of iza-bren 2.5 mg/kg D1D8Q3W, ORR: 85.0%, cORR: 77.5%; mDOR: 7.3 mo; mPFS: 8.2 mo. In the cohort of iza-bren 2.75 mg/kg D1D8Q3W, ORR: 91.9%, cORR: 78.4%; mDOR: 8.0 mo; mPFS: 8.3 mo. Iza-bren at 2.5 mg/kg D1D8 Q3W was selected as RP3D for combination with a PD-1 inhibitor and phase III study in China is in preparation for ES-SCLC. Fei Zhou, MD, PhD Organisers Partners Content of this presentation is copyright and responsibility of the author. Permission is required for re-use. INTERNATIONAL ESMO IASLC ASSOCIATION FOR THE STUDY ESTRO OF LUNG CANCER --- [Slide 4] Study Design Presented Key Eligibility Criteria Stage I Stage II ES-SCLC confirmed by Pts who failed standard treatment Treatment-naive pts histopathology and/or cytology Failed standard treatment (Stage I) or treatment-naive (Stage II) Iza-bren 2.75 mg/kg D1D8Q3W Iza-bren 2.5 mg/kg D1D8Q3W ECOG performance status of 0-1 + Serplulimab* 4.5 mg/kg Q3W + Serplulimab 4.5 mg/kg Q3W At least one measurable lesion per RECIST v1.1 Iza-bren 2.75 mg/kg D1D8Q3W Adequate organ and marrow function + Serplulimab 4.5 mg/kg Q3W Primary: ORR, RP2D (for combination treatment) Secondary: PFS, DCR, DOR, OS, PK, immunogenicity, DDI, safety Safety and efficacy results for stage II are presented. ECOG: Eastern Cooperative Oncology Group; ORR: objective response rate; RP2D: recommended phase 2 dose; PFS: progression-free survival; DCR: disease control rate; DOR: duration of response; OS: overall survival; PK: pharmacokinetics; DDI: drug-drug interaction : PD-1 inhibitor, which has been approved in China as first-line treatment for ES-SCLC in combined with carboplatin/etoposide. Fei Zhou, MD, PhD Organisers Content of this presentation is copyright and responsibility of the author. Permission is required for re-use Partners ESMD IASLC INTERNATIONAL ASSOCIATION FOR STUDY OF LONG CANCER ESTRO L ETOP-IBCSG PARTNERS FOUNDATION --- [Slide 5] Promising Efficacy Seen in Treatment-naïve Patients Total BOR, n (%) (N=77) Iza-bren 2.5 mg/kg D1D8Q3W Iza-bren D1D8 Q3W+Serplulimab 4.5 mg/kg Q3W PR (N = 40) Iza-bren 2.75 mg/kg D1D8Q3W (N = 37) Confirmed PR 68 (88.3) 34 (85.0) PR pending confirmation¹¹ 60 (77.9) 34 (91.9) 31 (77.5) SD 1 (1.3) 29 (78.4) 0 PD 5 (6.5) 1 (2.7) 3 (7.5) 4 (5.2) 2 (5.4) ORR, % (95% CI) 3 (7.5) 88.3 (79.0, 94.5) 1 (2.7) cORR, % (95% CI) 85.0 (70.2, 94.3) 77.9 (67.0, 86.6) 91.9 (78.1, 98.3) DCR, % (95% CI) 77.5 (61.5, 89.2) 94.8 (87.2, 98.6) 78.4 (61.8, 90.2) mDOR, mo (95% CI) 92.5 (79.6, 98.4) 97.3 (85.8, 99.9) 7.3 (5.6, 8.3) mPFS, mo (95% CI) 7.3 (5.3,8.3) 8.0 (5.5,8.6) 8.2 (6.7, 9.6) 8.2 (4.4,9.6) Median FU for PFS, mo (95% CI) 8.3 (6.9,9.7) 10.8 (8.3, 12.3) 9.8 (8.1, 12.4) 10.8 (8.3, 12.5) 12-mo OS rate, % (95% CI) 80.8 (66.1, 89.6) 85.7 (68.7, 93.9) 76.5 (51.4, 89.8) Median FU for OS, mo (95% CI) 10.5 (9.7, 11.3) 10.5 (9.7, 11.6) 10.4 (9.2,11.7) Patients with at least one post baseline scan were included in the analysis. [1] Patients still on study with tumor assessment of PR who have not yet reached to the next time point of tumor assessment Cl: confidence interval; cORR: confirmed objective response rate; PR: partial response; SD: stable disease; PD: progressive disease; FU: follow-up time. Data cutoff: November 30th, 2025 Fei Zhou, MD, PhD Organisers Partners Content of this presentation is copyright and responsibility of the author. Permission is required for re-use. ESMO IASLC INTERNATIONAL 9 FOR STUDY ESTRO 2 ETOP-IBCSG of Lund CANCER PARTNERS FOUNDATION --- [Slide 6] Depth & Duration of Response Iza-bren 2.5 mg/kg D1D8Q3W+Serplulimab 4.5 mg/kg Q3W #0 Iza-bren 2.75 mg/kg D1D8Q3W+Serplulimab 4.5 mg/kg Q3W so ORR = 85.0% I Confirmed Partial Response Partal Response as Stable Decease Deease 40 40 ORR = 91.9% . Contened Response Partal Response I Disease Onego Basellne I (%) 20 43 Criwn 0 I 2 Chenge I I # Griends 1 8 - 40 40 40 40 40 80 100 100 60 mDOR = 7.3 mo Partial Response 40 Stable Disease . Person Response 40 Progressive Disease mDOR = 8.0 mo Disease 43 Deesse 20 20% Growth 29 0 Change from Baseline, Chenge I # I 9 20 30% Numer 3 40 40 40 60 # 80 -100 100 0 3 Q 13 1 12 Month Month Iza-bren 2.5 mg/kg D1D8Q3W+Serplulimab: 100% of patients with tumor shrinkage and the median (range) shrinkage (%) was -64.4 (-92.4, -3.1). Iza-bren 2.75 mg/kg D1D8Q3W+Serplulimab: 100% of patients with tumor shrinkage and the median (range) shrinkage (%) was -63.6 (-100.0, - -19.6). Data cutoff: November 30th, 2025 Fei Zhou, MD, PhD Organisers Partners Content of this presentation is copyright and responsibility of the author. Permission is required for re-use. INTERNATIONAL MD IASLC FOR THE STUDY ESTRO L ETOP OF LUNG CANCER PARTNER --- [Slide 7] Conclusions Iza-bren ES-SCLC. combined with serplulimab as a first-line treatment showed a tolerable and manageable safety profile in patients with Hematologic support. toxicities were the most common AEs, but were effectively managed by supportive care and growth factor Rate mg/kg of iza-bren treatment discontinuation due to TRAEs was low overall (7.3%), with rates of 2.4% in the iza-bren 2.5 D1D8Q3W cohort and 12.2% in the 2.75 mg/kg D1D8Q3W cohort. Encouraging antitumor activity was observed with iza-bren combined with serplulimab in 1L ES-SCLC: In the cohort of iza-bren 2.5 mg/kg D1D8Q3W, ORR: 85.0%, cORR: 77.5%; mDOR: 7.3 mo; mPFS: 8.2 mo. In the cohort of iza-bren 2.75 mg/kg D1D8Q3W, ORR: 91.9%, cORR: 78.4%; mDOR: 8.0 mo; mPFS: 8.3 mo. Iza-bren at 2.5 mg/kg D1D8 Q3W was selected as RP3D for combination with a PD-1 inhibitor and phase III study in China is in preparation for ES-SCLC. Fei Zhou, MD, PhD Organisers Partners Content of this presentation is copyright and responsibility of the author. Permission is required for re-use. INTERNATIONAL ESMO IASLC ASSOCIATION FOR THE STUDY ESTRO 2 OF LUNG CANCER

[Slide 1] single-arm phase II Frontline ES-SCLC ADC + PD-1 in ES-SCLC Topoisomerase-1 ADC + PD-1 strategy ORR: 77 evaluable pts 88.3% mPFS: 8.2 mo L Follow-up: 10.5 mo 2.5 mg/kg 2.75 mg/kg DOSE SIGNAL 2.5 mg/kg 85% KEY OUTCOMES 2.75 mg/kg 91.9% cORR: 77.9% DCR: 94.8% SAFETY Early 12-mo OS 80.8% ! Hematologic toxicity high L mDOR: 7.3 mo Anemia 93.9% Thrombocytopenia 72% @DrRishabhOnco Neutropenia 62% ! Discontinuation: 7.3% ! 2 treatment-related deaths High ORR (88.3%) in single-arm Phase II ADC + PD-1 Encouraging early OS signal and manageable safety no control arm 2.5 mg/kg selected

[Slide 1] Study Design Key Eligibility Criteria Presented Stage 1 Stage И ES-SCLC confirmed by Pts who failed standard treatment elcc histopathology and/or cytology Treatment have pts European Lung Cancer Congress 2026 Failed standard treatment (Stage 1) or treatment-naive (Stage 11) Iza-bren 2.75 mg/kg D1D8Q3W 12a bren 25 mg/kg D1D8Q3W ECOG performance status of 0-1 Serplulimab* 4.5 mg/kg Q3W Serplulimab 45 mg/kg Q3W At least one measurable lesion per RECIST v1.1 iza bren 2.75 mg/kg D1D8Q3W Adequate organ and marrow function Serplulimab 4.5 mg/kg Q3W Primary: ORR, RP2D (for combination treatment) Secondary: PFS, DCR, DOR, OS, PK, immunogenicity, DDI, safety Safety and efficacy results for stage 11 are presented. ECOG: Eastern Cooperative Oncology Group; ORR: objective response caler, RP2D: recommended phase 2 dose, PFS: progression tree survively DCR: disease conted 100, DOR: d response, % and survival; PK: pharmacokinelics; DDI: drug-drug interaction PD-1 inhibitor, which has been approved in China as first line treatment for ES-SCLC n combined with carboplain/reloposide. Fel Zhou, MD, PhD Organises have Content of this presentation is copyright and responsibility of the author Permission is required for 00-USA ASLC ESTRO ETOP-IBCSG elcc European Lung Cancer Congress 2026 --- [Slide 2] Depth & Duration of Response za bren 2.5 mg/kg D1D8Q3W Serplulimab 4.5 mg/kg Q3W lza bren 2 75 mg/kg D1D8Q3W Serplulimab 4.5 Q3W ORR 85.0% ORR 91.9% elcc European Lung Cancer Congress 2026 mDOR 7.3 mo mDOR 8.0mo Iza-bren 2.5 mg/kg D1D8Q3W+Serplulimab: 100% of patients with tumor shrinkage and the median (range) shrinkage (%) was -64.4 (-92.4,-3.1). Iza-bren 2.75 mg/kg D1D8Q3W+Serplulimab: 100% of patients with tumor shrinkage and the median (range) shrinkage (%) was -63.6(-100.0, -19.6). Data cutoff: November 10th, 2025 Fei Zhou, MD, PhD Organisers haves Content of this presentation is copyright and responsibility of the author Permission is required for re-use ESMO IASUC ESTRO ETOP-MCSS elcc European Lung Cancer Congress 2026 --- [Slide 3] PFS 100% Total lica-bren 2.5 mgkg / AS many cow Us-bren Consored 2.75 mg/kg 45 mykg can elcc European Lung Cancer Congress 2026 Progression-free 50% survival 75% probability 25% mPFS (95% CI) Total: 8.2 (6.7, 9.6) Iza-bren 2.5 mg/kg D1D8Q3W + Serplulimab: 8.2 (4.4,9.6) Iza-bren 2.75 mg/kg D1D8Q3W + Serplulimab: 8.3 (6.9,9.7) 0% 0 $ 12 Months Subjects at risk 77 61 42 20 40 32 21 11 of 37 29 21 3 OS was immalure at the time of DCO. Data cutsff: November VP. 2025 Fel Zhou, MD, PhD Organisers Patients Content of this presentation is copyright and responsibility of the author Permission is required for re-use ASLC - ESTRO TOP BCSO elcc European Lung Cancer Congress 2026 --- [Slide 4] TRAEs with Frequency ≥ 30% Anaemia Thrombocytopenia Gradez3 TRAEs which were predominantly hematologic in nature, Leukopenia were able to be effectively managed with standard supportive measures including dose reductions and growth factor support. Neutropenia 9.8% of patients had dose reduction and 1.2% of patients had dose Decreased appetite discontinuation due to neutropenia. The median time to resolution of elcc European Lung ALT increased Cancer Congress 2026 Grade 3 or 4 neutropenia was 3 days. Most only had 1 episode. Preferred Term Asthenia Neutropenic fever rate was 2.4%. Nausea 6.1% of patients had dose reduction and 0 patient had dose AST increased discontinuation due to anaemia. The median time to resolution of Hypoalbuminaemia Grade 3 anaemia was 7 days. Most had 2 episodes. Stomatitis All grade and grade>3 infection related AEs rate were 20.7% and 8.9%. Hyponatraemia Two deaths related to iza-bren (one due to multiple organ dysfunction Rash syndrome, and one due to pneumonia and respiratory failure) were Lymphocyte count decreased reported. 100 60 60 40 20 0 20 40 60 80 100 Incidence (%) Two cases (2.4%) of ILD were reported (one Grade 2, iza-bren 25 Iza-bren 2.5mg/kg D1D8Q3W Serplulimab 4.5mg/kg Q3W Grade 1-2 mg/kg D1D8Q3W cohort; one Grade 3, 2.75 mg/kg D1D8Q3W cohort). Iza-bren 2.75mg/kg D1D8Q3W Serplulimab 5mg/kg Q3W Grade 1-2 No new safety signals were identified. Iza-bren 2.5mg/kg D1D8Q3W Serplulimab 4.5mg/kg Q3W Grade as TRAE: treatment related adverse event; Iza-bren 2.75mg/kg D1D8Q3W Serplulimab 4.5mg/kg Q3W Grade 23 Data cutoff: November 30°, 2025 Patients Fei Zhou, MD, PhD Organisers IASLC I ESTRO ETOP-IBCSG Content of this presentation is copyright and responsibility of the author. Permission is required for re-use ESMO lcc European Lung Cancer Congress 2026

[Slide 1] Study Design Presented Key Eligibility Criteria Stage I Stage II ES-SCLC confirmed by Pts who failed standard treatment Treatment-naive pts histopathology and/or cytology Failed standard treatment (Stage I) Iza-bren 2.5 mg/kg D1D8Q3W or treatment-naïve (Stage II) Iza-bren 2.75 mg/kg D1D8Q3W + Serplulimab 4.5 mg/kg Q3W ECOG performance status of 0-1 + Serplulimab 4.5 mg/kg Q3W At least one measurable lesion per Iza-bren 2.75 mg/kg D1D8Q3W RECIST v1.1 + Serplulimab 4.5 mg/kg Q3W Adequate organ and marrow function Primary: ORR, RP2D (for combination treatment) Secondary: PFS, DCR, DOR, OS, PK, immunogenicity, DDI, safety Safety and efficacy results for stage II are presented ECOG: Eastem Cooperative Oncology Group ORR: objective response rate; RP2D: recommended phase 2 dose; PFS: progression free survival; DCR: disease control rate; DOR: duration of response; OS: overall survival PK: pharmacokinetics, DDI: drug-drug interaction : PD-1 inhibitor, which has been approved in China as first-line treatment for ES-SCLC in combined with carboplatin/etoposide. Fei Zhou, MD, PhD Organisers Partners Content of this presentation is copyright and responsibility of the author Permission is required for re-use ADERNATIONAL ESMO IASLC ESTRO ETOP-IBCSG or LUNG CANCER PARTNERS FOUNDATION --- [Slide 2] TRAEs with Frequency ≥ 30% Anaemia Grade>3 TRAEs which were predominantly hematologic in nature, Thrombocytopenia were able to be effectively managed with standard supportive Leukopenia measures including dose reductions and growth factor support. Neutropenia 9.8% of patients had dose reduction and 1.2% of patients had dose Decreased appetite discontinuation due to neutropenia. The median time to resolution of ALT increased Grade 3 or 4 neutropenia was 3 days. Most only had 1 episode. Preferred Term Asthenia Neutropenic fever rate was 2.4%. Nausea 6.1% of patients had dose reduction and 0 patient had dose discontinuation due to anaemia. The median time to resolution of AST increased Grade 3 anaemia was 7 days. Most had 2 episodes. Hypoalbuminaemia All grade and grade>3 infection related AEs rate were 20.7% and Stomatitis 8.9%. Hyponatraemia Two deaths related to iza-bren (one due to multiple organ dysfunction Rash syndrome, and one due to pneumonia and respiratory failure) were Lymphocyte count decreased reported. 100 80 60 40 20 0 20 40 60 80 100 Incidence (%) Two cases (2.4%) of ILD were reported (one Grade 2, iza-bren 2.5 Iza-bren 2.5mg/kg D1D8Q3W Serplulimab 4.5mg/kg Q3W Grade 1-2 mg/kg D1D8Q3W cohort; one Grade 3, 2.75 mg/kg D1D8Q3W cohort). Iza-bren 2.75mg/kg D1D8Q3W Serplulimab 4.5mg/kg Q3W Grade 1-2 No new safety signals were identified. Iza-bren 2.5mg/kg D1D8Q3W Serplulimab 4.5mg/kg Q3W Grade 23 TRAE: treatment related adverse event; Iza-bren 2.75mg/kg D1D8Q3W Serplulimab 4.5mg/kg Q3W Grade a3 Data cutoff: November 30th, 2025 Fei Zhou, MD, PhD Organisers Partners Content of this presentation is copyright and responsibility of the author Permission is required for re-use ESMO IASLC ESTRO L ETOP-IBCSG or CANCER PARTNERS --- [Slide 3] PFS 100% Total Iza-bren 2.5 mg/kg D1D8Q3W+Serplulimab 4.5 mg/kg Q3W Iza-bren 2.75 mg/kg D1D8Q3W+Serplulmab 4.5 mg/kg Q3W + Censored 75% Progression-free survival probability 50% 25% mPFS (95% CI) Total: 8.2 (6.7, 9.6) Iza-bren 2.5 mg/kg D1D8Q3W + Serplulimab: 8.2 (4.4, 9.6) Iza-bren 2.75 mg/kg D1D8Q3W + Serplulimab: 8.3 (6.9, 9.7) 0% 0 3 6 9 12 15 Months Subjects at risk 77 61 42 20 8 0 40 32 21 11 5 0 37 29 21 9 3 0 OS was immature at the time of DCO Data cutoff: November 30th, 2025 Fei Zhou, MD, PhD Organisers Partners Content of this presentation is copyright and responsibility of the author Permission is required for re-use ESMO IASLC INTERNATIONAL STUDY ESTRO LUNG CANCER L ETOP-IBCSG PARTNERS FOUNDATION --- [Slide 4] Depth & Duration of Response Iza-bren 2.5 mg/kg D1D8Q3W+Serplulimab 4.5 mg/kg Q3W Iza-bren 2.75 mg/kg D1D8Q3W+Serplulimab 4.5 mg/kg Q3W ORR = 85.0% ORR = 91.9% - mDOR = 7.3 mo Disease mDOR = 8.0 mo Iza-bren 2.5 mg/kg D1D8Q3W+Serplulimab: 100% of patients with tumor shrinkage and the median (range) shrinkage (%) was -64.4 (-92.4, -3.1). Iza-bren 2.75 mg/kg D1D8Q3W+Serplulimab: 100% of patients with tumor shrinkage and the median (range) shrinkage (%) was -63.6 (-100.0, -19.6). Data cutoff: November 30th, 2025 Fei Zhou, MD, PhD Organisers Partners Content of this presentation is copyright and responsibility of the author. Permission is required for re-use ESMO IASLC ESTRO L ETOP-IBCSG PARTNERS FOUNDATION

[Slide 1] TRAEs with Frequency ≥ 30% Grade23 TRAEs which were predominantly hematologic in nature, Anna were able to be effectively managed with standard supportive measures including dose reductions and growth factor support. Leukopensa 9.8% of patients had dose reduction and 1.2% of patients had dose Neutriperia discontinuation due to neutropenia. The median time to resolution of Decreased appellite Grade 3 or 4 neutropenia was 3 days. Most only had 1 episode. ALT increased Term Neutropenic fever rate was 2.4%. Assenia 6.1% of patients had dose reduction and 0 patient had dose Names discontinuation due to anaemia. The median time to resolution of AST increased Grade 3 anaemia was 7 days. Most had 2 episodes All grade and grade23 infection related AEs rate were 20 7% and I 8.9% Two deaths related to iza-bren (one due to multiple organ dysfunction Resh syndrome, and one due to pneumonia and respiratory failure) were Lymphoryte - decreased reported 100 so 00 40 20 0 20 40 00 80 100 Incidence (%) Two cases (2.4%) of ILD were reported (one Grade 2, iza-bren 2.5 Lie-bren 1. fing kg 010033W Suptutions limplig ase Gode 1-2 mg/kg D1D8Q3W cohort; one Grade 3, 2.75 mg/kg D1D8Q3W cohort). - tree 1 Hinging DIDBCTOR Singhg I I Date 1-2 No new safety signals were identified. - 1 Singleg 010439W - I Grade is - 2. Timghg DID#GOW 4. I I Gase as TRAE: treatment related adverse meet, Data cuteff November 300, 2025 Fal Thou, NO, PhO Signature Person Content of the presentation a appyinght and responsibility of the author Permission a required for . - ESMD IASLC I ESTRO L STOP-IBCS --- [Slide 2] Promising Efficacy Seen in Treatment-naïve Patients ZA bren D1D8 Q3W+Serplulimab 4.5 mg/kg Q3W Total za bren 2.5 mg/kg D1D8Q3W za- bren 2.75 mg/kg D1D8Q3W (N=77) (N 40) (N 37) BOR, n (%) PR 68 (88.3) 34 (85.0) 34(91.9) Confirmed PR 60 (77.9) 31 (77.5) 29(78.4) PR pending confirmation¹ 1(1.3) 0 1(27) SD 5 (6.5) 3 (7.5) 2(5.4) PD 4 (5.2) 3 (7.5) 1 (2.7) ORR, % (95% CI) 88.3(79.0,94.5) 85 (70.2, 94.3) 91.9(78.1,96.3) cORR, % (95% CI) 77.9(67.0,86.6) 77.5(61.5,89.2) 78.4(61.8,90.2) DCR, % (95% CI) 94.8 (87.2,98.6) 92.5 (796,98.4) 973(658,999) mDOR, mo (95% CI) 7.3 (5.6,8.3) 7,3(5,8,8.3) 8.0(5.5,8.6) mPFS, mo (95% CI) 8.2 (6.7,9.6) 8.2 (4.4,9.6) 8.3(6.9,9,9.7) Median FU for PFS, mo (95% CI) 10.8 (8.3, 12.3) 9.8(8.1,12.4) 10.8(8.3, 12.5) 12-mo os rate, % (95% CI) 80. 8(66.1,89.6) 657(68.7,93.9) 76.5(51.4,89.8) Median FU for os, mo (95% CI) 10.5 (97,11.3) 10.5(9.7,11.6) 10.4(0.2,11.7) Patients with at less one post baseline scan were included in the analysis [1] Patients is on study with tumor assessment of PR who have not yet reached to the new time paint of fundr assessment CL: confidence interval, CORR numbermed abjective response rate; PR parial response; 10: stable decesse, PD: progressue finease FU. follow-up time Data cutaff November 100, 2025 Fel Day, MD, PMD Departments Patient's Contant of his presentation a copyment and responsibility of be author Permission a required for - use ESMD IASLC ESTRO X STOP 6 - - MARER 2016 --- [Slide 3] Study Design Presented Key Eligibility Criteria Stage I Stage II ES-SCLC confirmed by Pts who failed standard treatment Treatment have pts histopathology and/or cytology Failed standard treatment (Stage 1) za bren 25 mg/kg D1D8Q3W or treatment-naive (Stage II) Iza-bren 2.75 mg/kg D1D8Q3W Serplulimab 4.5 mg/kg Q3W ECOG performance status of 0-1 + Serplulimab 4.5 mg/kg Q3W At least one measurable lesion per Iza bren 2.75 mg/kg D1D8Q3W RECIST v1.1 Serplulimab 4.5 mg/kg Q3W Adequate organ and marrow function Primary: ORR, RP2D (for combination treatment) Secondary: PFS, DCR, DOR, OS, PK, immunogenicity, DDI, safety Salety and officacy results be stage a any presented ECOO Easien Cooperative Oneslogy Crisp, ORR, objective response - RP20: recommended phose 2 dose, PFS: progression to survivel DCR, danate control rate, DOR: duration of response, 05: overall and PK pharmacoknetics, DDI aug any interaction PD 1 whole which has teen approved in China as line line beatment or ES-SCLO n combined with carboplation/uloposide Fel they, MD, PEO Organizers Tature Centent of to peneration a appyinght and responsability of be subbor Permission . required for use ESMD ARE ESTR9 X EYOP-ISCSO 026 --- [Slide 4] TRAEs with Frequency ≥ 30% Grade23 TRAEs which were predominantly hematologic in nature, Antenia were able to be effectively managed with standard supportive Thromborytopens measures including dose reductions and growth factor support. Leukapenia 9.8% of patients had dose reduction and 1.2% of patients had dose Neutroperia discontinuation due to neutropenia. The median time to resolution of Decreased appealle Grade 3 or 4 neutropenia was 3 days Most only had 1 episode. ALT increased Personal 1 Neutropenic fever rate was 2.4% Alberia 6.1% of patients had dose reduction and 0 patient had dose I discontinuation due to anaemia The median time to resolution of AST increased Grade 3 anaemia was 7 days. Most had 2 episodes, Hypeabuminasma All grade and grade23 infection related AEs rate were 20.7% and I 8.9% Hyperolismis Two deaths related to iza-bren (one due to multiple organ dysfunction Rash syndrome, and one due to pneumonia and respiratory failure) were Lymphoryte - decreased reported. 100 00 00 2 20 9 20 8 8 a 100 incidence (%) Two cases (2.4%) of ILD were reported (one Grade 2, iza-bren 2.5 - 1. finglig 010633W Septutimes 4. Singlig are Grade I mg/kg D1D8Q3W cohort, one Grade 3, 2.75 mg/kg D1D8Q3W cohort). - bren 1 Hinghg DIDBQ3W Segistrial Linghg 00w One 1-2 No new safety signals were identified. - 2.5mg/kg fingling GSW I Grade a - 1. ringhg 0100G3W Septiment 4. Singhing any Gate 13 TRAE: treatment related adverse east, Data cuteff: November 30°, 2025 Fel thou, NO, Pb0 Departments Person Contant of to presentation . appyright and responsibility of the author Permassion is required to 10 use ESMD ARC ESTRO h ETOP-IBCS --- [Slide 5] Promising Efficacy Seen in Treatment-naïve Patients za bren D1DB Q3W+Serplulimab 4.5 mg/kg Q3W Total za bren 25 mg/kg D1D8Q3W za bren 2.75 mg/kg D1D8Q3W (N=77) (N=40) (N=37) BOR, n (%) PR 68 (88.3) 34(85.0) 34(91.9) Confirmed PR 60 (77.9) 31(77.5) 29(78.4) PR pending confirmation¹ 1(1.3) 0 1(27) SD 5(6.5) 3(7.5) 2 (5.4) PD 4(5.2) 3(7.5) 1 (2.7) ORR, % (95% CI) 88,3(79.0,94.5) 85.0(70.2,94.3) 91.9(781,98.3) cORR, % (95% CI) 77.9(67.0,86.6) 77.5(61.5,89.2) 78.4(61.8,90.2) DCR, % (95% CI) 948(872,986) 92.5(796,98.4) 97.3(858,999) mDOR, mo (95% CI) 7.3(5,8,8.3) 7.3(5,8.3) 8.0(5,5,8.6) mPFS, mo (95% CI) 8.2(6.7,9.6) 8.2(4.4,9.6) 8.3(6.9,9,9.7) Median FU for PFS, mo (95% CI) 10.8(8,123) 9.8(8.1,12.4) 10.8(8.3,12.5) 12-mo os rate, % (95% CI) 80.8(66.1,89.6) 65.7(68.7,93.9) 76.5(51.4,89.8) Median FU for OS, mo (95% CI) 10.5(9.7,11.3) 10.5(9.7,11.6) 10.4(0.2,11.7) Patients - # less one post benefine scan were included in the analysis [1] Patients a on study with tumor assessment of PR who have not yet reached to the need time paint of fundr assessment Ct: confidence interval, CORR nonfirmed abjective response rate PR partal response, 10 stable doesse, PD: progressue deesse, FU. follow-up time Data cutaff: November 10", 2025 Fel Zoou, MD, PtD Organizers - Contant of his presentation is aspymght and responsibility of be author Permission a required for to use ESMD LAME ESTRO X STOP 6 elcc - -- BARER - --- [Slide 6] Depth & Duration of Response ta bren 2.5 mg/kg D1D8Q3W+Serplulimab 45 mg/kg Q3W iza bren 2 75 mg/kg D1D8Q3W Serplulimab 4.5 mg/kg Q3W ORR R 85.0% ORR . 91 9% mDOR = 7.3 mo In mDOR = 8.0 mo E If Iza-bren 2.5 mg/kg D1D8Q3W+Serplulimab: 100% of patients with tumor shrinkage and the median (range) shrinkage (%) was -64.4 (-92.4, -3.1). Iza-bren 2.75 mg/kg D1D8Q3W+Serplulimab: 100% of patients with tumor shrinkage and the median (range) shrinkage (%) was -63.6 (-100.0, -19.6). Data cutoff November 30°, 2023 Fel Zhou, MD, PhD I Content of the presentation . supyright and responsibility of the author Permission is required for re-use ESMD ARC ESTRO X TOP-IBC