Summit Therapeutics Inc. · NASDAQ:SMMT

Summit Therapeutics — WCLC Update Call (September 2025)

21 slides from Summit Therapeutics's conference presentation, Sep 8, 2025

  1. Slide 1: Summit Therapeutics WCLC Update Call

    Summit Therapeutics WCLC Update Call September 8, 2025 8:00am ET

  2. Slide 2: Forward Looking Statement

    Forward Looking Statement Any statements in this press release about the Company’s future expectations, plans and prospects, including but not limited to, statements about the clinical and preclinical development of the Company’s product candidates, entry into and actions related to the Company’s pa

  3. Slide 3: Ivonescimab vs Placebo Plus Chemo, Phase 3 in EGFR+ NSCLC: HARMONi

    Ivonescimab vs Placebo Plus Chemo, Phase 3 in Patients with EGFR+ NSCLC Progressed with 3rd gen EGFR-TKI Treatment: HARMONi Jonathan W. Goldman1, Antonio Passaro2, Janessa Laskin3, Delvys Rodrigues-Abreu4, Antonio Calles5, Lyudmila Bazhenova6, Giuseppe Lo Russo7, Natasha Leighl8, Frederico Cappuzzo9

  4. Slide 4: Phase 3 Study Design

    Phase 3 Study Design Ivonescimab + Endpoints: Key Eligibility Criteria Chemotherapy Primary Locally advanced or (N = 219) • OS, PFS by IRRC per RECIST 1.1 metastatic NSCLC: • EGFR sensitizing R Secondary mutation+ 1:1 • ORR by IRRC, DoR, safety and • Progressed on 3rd gen tolerability EGFR-TKI N=438

  5. Slide 5: Background

    Background Global Enrollment Time Period: Asia: Jan 2022 – Nov 2022 Western: May 2023 – Oct 2024 Timing of Global Analyses: PFS Primary Analysis: Jul 2024 PFS Total Analysis: Apr 2025 OS Primary Analysis: Apr 2025 OS Longer-term FU of Western pts* Analysis: Sep 2025 *For longer-term analysis for OS,

  6. Slide 6: Phase 3 Study Design

    Phase 3 Study Design Ivonescimab + Endpoints: Key Eligibility Criteria Chemotherapy Primary Locally advanced or (N = 219) • OS, PFS by IRRC per RECIST 1.1 metastatic NSCLC: • EGFR sensitizing R Secondary mutation+ 1:1 • ORR by IRRC, DoR, safety and • Progressed on 3rd gen tolerability EGFR-TKI N=438

  7. Slide 7: Demographic and Baseline Characteristics

    Demographic and Baseline Characteristics Arms were well-balanced; majority were females, ECOG 1, never smokers; 25% with brain mets Ivonescimab+chemo Placebo+chemo Characteristic, n (%) (N=219) (N=219) Age – Median (range) 62 (32-84) 60 (36-84) ≥65 yr 83 (37.9) 88 (40.2) Female 130 (59.4) 127 (58.0)

  8. Slide 8: Primary Endpoint: PFS by IRRC

    Primary Endpoint: PFS by IRRC Statistically significant and clinically meaningful benefit with ivonescimab 100 median FU: 22.3 mo Events, n (%) Median HR P Value (mo) (95% CI) 80 Ivonescimab+chemo 129 (75.0) 6.8 0.52 <0.0001 Placebo+chemo 146 (84.4) 4.4 (0.41-0.66) 60 PFS (%) 54.0% 40 34.7% Ivonesci

  9. Slide 9: PFS by IRRC – Subgroup Analysis

    PFS by IRRC – Subgroup Analysis Consistent across pre-defined subgroups Ivonescimab Placebo + Favors Ivonescimab Favors Placebo Hazard Ratio + chemo chemo + chemo + chemo (95% CI) Ivo + chemo Pbo + chemo HR (Events/N) (Events/N) Overall population 129/172 146/173 0.52 (0.41-0.66) Age <65 years 89/11

  10. Slide 10: PFS by Presence or Absence of Brain Mets

    PFS by Presence or Absence of Brain Mets 100 100 Pts with Brain Mets at Baseline: Pts with No Brain Mets at Baseline: HR = 0.34 (95% CI: 0.20-0.57) HR = 0.59 (95% CI: 0.45-0.77) 80 80 60 Ivonescimab+chemo Ivonescimab+chemo PFS (%) 60 PFS (%) Placebo+chemo Placebo+chemo 40 40 20 20 0 0 0 3 6 9 12 15

  11. Slide 11: PFS by IRRC: Primary Analysis vs Total PFS Analysis

    PFS by IRRC: Primary Analysis vs Total PFS Analysis Consistent PFS with Primary and Total (All Patients) PFS Analysis including all NA & EU patients 100 Ivonescimab+chemo (Primary) Primary analysis (median FU: 22.3 mo, N=345): HR = 0.52 (95% CI: 0.41-0.66) Placebo+chemo (Primary) 80 Ivonescimab+chem

  12. Slide 12: Primary Endpoint: Overall Survival

    Primary Endpoint: Overall Survival Favorable Trend Observed; NA & EU Follow-up Not Yet Mature No detrimental impact on any predefined subgroups 100 Events, n Median HR P Value (%) (mo) (95% CI) 80 Ivonescimab + chemo 122 (55.7) 16.8 0.79 0.0570 (0.62-1.01) Placebo + chemo 140 (63.9) 14.0 60 OS (%) I

  13. Slide 13: Overall Survival: Longer Term Western Follow-up

    Overall Survival: Longer Term Western Follow-up OS stable with longer term Western Data, nominal p=0.0332 Events, n Median HR P Value 100 (%) (mo) (95% CI) Ivonescimab + chemo 134 (61.2) 16.8 0.78 0.0332 (0.62-0.98) 80 Placebo + chemo 157 (71.7) 14.0 Region Median FU Median OS 60 (mo) (mo) OS (%) NA

  14. Slide 14: Overall Survival Subgroup Analysis – Longer Term FU

    Overall Survival Subgroup Analysis – Longer Term FU Consistent across pre-defined subgroups Ivonescimab Placebo Favor Ivonescimab Favor Placebo Hazard Ratio + chemo + chemo + chemo + chemo (95% CI) (Events/N) (Events/N) Overall population 134/219 157/219 0.78 (0.62-0.98) Age <65 years 90/136 99/131

  15. Slide 15: Reminder: Background

    Reminder: Background Global Enrollment Time Period: Asia: Jan 2022 – Nov 2022 Western: May 2023 – Oct 2024 Timing of Global Analyses: PFS Primary Analysis: Jul 2024 PFS Total Analysis: Apr 2025 OS Primary Analysis: Apr 2025 OS Longer-term FU of Western pts* Analysis: Sep 2025 *For longer-term analys

  16. Slide 16: Overall Response Rate and Duration of Response

    Overall Response Rate and Duration of Response By IRRC 100% 80% 84% DoR (mo) Ivonescimab + Placebo + DCR chemo chemo 73% 60% n 98 75 ORR/DCR DCR 40% Median (95% CI) 7.6 (5.5-10.6) 4.2 (2.9-4.7) 45% ORR 34% 20% ORR 0% Ivonescimab+chemo Placebo+chemo CI=confidence interval; DCR=disease control rate; D

  17. Slide 17: Treatment-Related Adverse Events (TRAEs)

    Treatment-Related Adverse Events (TRAEs) Most common were lab abnormalities, nausea, decreased appetite 50.0 95.0 Ivonescimab + Placebo + Total 42.2 93.1 TRAE, n(%) chemo chemo Anemia 10.1 12.4 49.1 56.4 (N=218) (N=218) 12.8 45.0 WBC count decreased 11.0 44.0 Any Grade 207 (95.0) 203 (93.1) Neutroph

  18. Slide 18: Immune-related and VEGF-related TRAEs

    Immune-related and VEGF-related TRAEs Most common irAEs: hypo/hyperthryroidism, transaminase elevation, rash; mostly low grade Most common VEGF-related TRAEs: proteinuria, hypertension, hemorrhage; mostly low grade irAE VEGF-related 9.6 33.0 7.3 33.5 Total Total 6.0 17.9 3.2 15.1 Hypothyroidism 0.5

  19. Slide 19: Summary

    Summary • Ivonescimab had a significant and clinically meaningful PFS benefit in EGFRm+ NSCLC patients post-3rd gen TKI • Reduced risk of progression or death by 48% vs chemotherapy, HR=0.52 • Consistent efficacy across pre-defined subgroups • Increased ORR and DoR • OS final analysis showed favorab

  20. Slide 20: Acknowledgements

    Acknowledgements Thank you to everyone who made this trial possible: • The patients and their families • The personnel at all the clinical study sites • The scientists, regulatory, operations, and other teams within Summit and Akeso who helped develop ivonescimab and supported the study Ivonescimab

  21. Slide 21: Questions & Answers

    ( Summit therapeutics. Questions & Answers

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